util/reflect: add StructFieldNameByTag

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

.gitea/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,18 @@
+---
+name: Bug report
+about: For reporting bugs in micro
+title: "[BUG]"
+labels: ''
+assignees: ''
+
+---
+
+**Describe the bug**
+
+1. What are you trying to do?
+2. What did you expect to happen?
+3. What happens instead?
+
+**How to reproduce the bug:**
+
+If possible, please include a minimal code snippet here.

.gitea/ISSUE_TEMPLATE/feature-request---enhancement.md

@@ -0,0 +1,17 @@
+---
+name: Feature request / Enhancement
+about: If you have a need not served by micro
+title: "[FEATURE]"
+labels: ''
+assignees: ''
+
+---
+
+**Is your feature request related to a problem? Please describe.**
+A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
+
+**Describe the solution you'd like**
+A clear and concise description of what you want to happen.
+
+**Additional context**
+Add any other context or screenshots about the feature request here.

.gitea/ISSUE_TEMPLATE/question.md

@@ -0,0 +1,8 @@
+---
+name: Question
+about: Ask a question about micro
+title: ''
+labels: ''
+assignees: ''
+
+---

.gitea/autoapprove.yml

@@ -0,0 +1,28 @@
+name: "autoapprove"
+
+on:
+  pull_request_target:
+    types: [assigned, opened, synchronize, reopened]
+  workflow_run:
+    workflows: ["prbuild"]
+    types:
+      - completed
+
+permissions:
+  pull-requests: write
+  contents: write
+
+jobs:
+  autoapprove:
+    runs-on: ubuntu-latest
+    steps:
+      - name: approve
+        run: [ "curl -o tea https://dl.gitea.com/tea/main/tea-main-linux-amd64",
+               "chmod +x ./tea",
+               "./tea login add --name unistack --token ${{ secrets.GITHUB_TOKEN }} --url https://git.unistack.org",
+               "./tea pr --repo ${{ github.event.repository.name }}"
+        ]
+        if: github.actor == 'vtolstov'
+        id: approve
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}

.gitea/workflows/lint.yml

@@ -0,0 +1,24 @@
+name: lint
+on:
+  pull_request:
+    branches:
+    - master
+    - v3
+jobs:
+  lint:
+    name: lint
+    runs-on: ubuntu-latest
+    steps:
+    - name: setup-go
+      uses: actions/setup-go@v3
+      with:
+        go-version: 1.21
+    - name: checkout
+      uses: actions/checkout@v3
+    - name: deps
+      run: go get -v -d ./...
+    - name: lint
+      uses: https://github.com/golangci/golangci-lint-action@v3.4.0
+      continue-on-error: true
+      with:
+        version: v1.52

.gitea/workflows/pr.yml

@@ -0,0 +1,23 @@
+name: pr
+on:
+  pull_request:
+    branches:
+    - master
+    - v3
+jobs:
+  test:
+    name: test
+    runs-on: ubuntu-latest
+    steps:
+    - name: checkout
+      uses: actions/checkout@v3
+    - name: setup-go
+      uses: actions/setup-go@v3
+      with:
+        go-version: 1.21
+    - name: deps
+      run: go get -v -t -d ./...
+    - name: test
+      env:
+        INTEGRATION_TESTS: yes
+      run: go test -mod readonly -v ./...

.github.old/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,9 @@
+## Pull Request template
+Please, go through these steps before clicking submit on this PR.
+
+1. Give a descriptive title to your PR.
+2. Provide a description of your changes.
+3. Make sure you have some relevant tests.
+4. Put `closes #XXXX` in your comment to auto-close the issue that your PR fixes (if applicable).
+
+**PLEASE REMOVE THIS TEMPLATE BEFORE SUBMITTING**

.github.old/dependabot.yml

@@ -0,0 +1,26 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://help.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+
+version: 2
+updates:
+
+  # Maintain dependencies for GitHub Actions
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "daily"
+    commit-message:
+      prefix: "chore"
+      include: "scope"
+
+  # Maintain dependencies for Golang
+  - package-ecosystem: "gomod"
+    directory: "/"
+    schedule:
+      interval: "daily"
+    commit-message:
+      prefix: "chore"
+      include: "scope"
+

.github.old/workflows/autoapprove.yml

@@ -0,0 +1,24 @@
+name: "autoapprove"
+
+on:
+  pull_request_target:
+    types: [assigned, opened, synchronize, reopened]
+  workflow_run:
+    workflows: ["prbuild"]
+    types:
+      - completed
+
+permissions:
+  pull-requests: write
+  contents: write
+
+jobs:
+  autoapprove:
+    runs-on: ubuntu-latest
+    steps:
+      - name: approve
+        uses: hmarr/auto-approve-action@v3
+        if: github.actor == 'vtolstov' || github.actor == 'dependabot[bot]'
+        id: approve
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}

.github.old/workflows/automerge.yml

@@ -0,0 +1,21 @@
+name: "automerge"
+
+on:
+  pull_request_target:
+    types: [assigned, opened, synchronize, reopened]
+
+permissions:
+  pull-requests: write
+  contents: write
+
+jobs:
+  automerge:
+    runs-on: ubuntu-latest
+    if: github.actor == 'vtolstov'
+    steps:
+      - name: merge
+        id: merge
+        run: gh pr merge --auto --merge "$PR_URL"
+        env:
+          PR_URL: ${{github.event.pull_request.html_url}}
+          GITHUB_TOKEN: ${{secrets.TOKEN}}

.github.old/workflows/build.yml

@@ -1,55 +1,40 @@
 name: build
 on:
-  push:
+ push:
     branches:
     - master
+    - v3
 jobs:
   test:
     name: test
     runs-on: ubuntu-latest
     steps:
     - name: setup
-      uses: actions/setup-go@v2
+      uses: actions/setup-go@v3
       with:
-        go-version: 1.16
+        go-version: 1.17
+    - name: checkout
+      uses: actions/checkout@v3
     - name: cache
-      uses: actions/cache@v2
+      uses: actions/cache@v3
       with:
         path: ~/go/pkg/mod
         key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
         restore-keys: ${{ runner.os }}-go-
-    - name: sdk checkout
-      uses: actions/checkout@v2
-    - name: sdk deps
+    - name: deps
       run: go get -v -t -d ./...
-    - name: sdk test
+    - name: test
       env:
         INTEGRATION_TESTS: yes
       run: go test -mod readonly -v ./...
-    - name: tests checkout
-      uses: actions/checkout@v2
-      with:
-        repository: unistack-org/micro-tests
-        ref: refs/heads/master
-        path: micro-tests
-        fetch-depth: 1
-    - name: tests deps
-      run: |
-        cd micro-tests
-        go mod edit -replace="github.com/unistack-org/micro/v3=../"
-        go get -v -t -d ./...
-    - name: tests test
-      env:
-        INTEGRATION_TESTS: yes
-      run: cd micro-tests && go test -mod readonly -v ./...
   lint:
     name: lint
     runs-on: ubuntu-latest
     steps:
       - name: checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
       - name: lint
-        uses: golangci/golangci-lint-action@v2
+        uses: golangci/golangci-lint-action@v3.4.0
         continue-on-error: true
         with:
           # Required: the version of golangci-lint is required and must be specified without patch version: we always use the latest patch version.

.github.old/workflows/codecov.yml

@@ -0,0 +1,39 @@
+name: "codecov"
+
+on:
+  workflow_run:
+    workflows: ["build"]
+    types:
+      - completed
+  push:
+    branches: [ v3 ]
+  pull_request:
+    branches: [ v3 ]
+  schedule:
+    - cron: '34 1 * * 0'
+
+jobs:
+  codecov:
+    name: codecov
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [ 'go' ]
+
+    steps:
+    - name: checkout
+      uses: actions/checkout@v3
+    - name: setup
+      uses: actions/setup-go@v3
+      with:
+        go-version: 1.17
+    - name: Run coverage
+      run: go test -v -race -coverprofile=coverage.out -covermode=atomic ./...
+    - name: codecov
+      uses: codecov/codecov-action@v3.1.1

.github.old/workflows/codeql-analysis.yml

@@ -0,0 +1,78 @@
+# For most projects, this workflow file will not need changing; you simply need
+# to commit it to your repository.
+#
+# You may wish to alter this file to override the set of languages analyzed,
+# or to provide custom queries or build logic.
+#
+# ******** NOTE ********
+# We have attempted to detect the languages in your repository. Please check
+# the `language` matrix defined below to confirm you have the correct set of
+# supported CodeQL languages.
+#
+name: "codeql"
+
+on:
+  workflow_run:
+    workflows: ["prbuild"]
+    types:
+      - completed
+  push:
+    branches: [ master, v3 ]
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: [ master, v3 ]
+  schedule:
+    - cron: '34 1 * * 0'
+
+jobs:
+  analyze:
+    name: analyze
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [ 'go' ]
+        # CodeQL supports [ 'cpp', 'csharp', 'go', 'java', 'javascript', 'python' ]
+        # Learn more:
+        # https://docs.github.com/en/free-pro-team@latest/github/finding-security-vulnerabilities-and-errors-in-your-code/configuring-code-scanning#changing-the-languages-that-are-analyzed
+
+    steps:
+    - name: checkout
+      uses: actions/checkout@v3
+    - name: setup
+      uses: actions/setup-go@v3
+      with:
+        go-version: 1.17
+    # Initializes the CodeQL tools for scanning.
+    - name: init
+      uses: github/codeql-action/init@v2
+      with:
+        languages: ${{ matrix.language }}
+        # If you wish to specify custom queries, you can do so here or in a config file.
+        # By default, queries listed here will override any specified in a config file.
+        # Prefix the list here with "+" to use these queries and those in the config file.
+        # queries: ./path/to/local/query, your-org/your-repo/queries@main
+
+    # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
+    # If this step fails, then you should remove it and run the build manually (see below)
+    - name: autobuild
+      uses: github/codeql-action/autobuild@v2
+
+    # ℹ️ Command-line programs to run using the OS shell.
+    # 📚 https://git.io/JvXDl
+
+    # ✏️ If the Autobuild fails above, remove it and uncomment the following three lines
+    #    and modify them (or add more) to build your code if your project
+    #    uses a compiled language
+
+    #- run: |
+    #   make bootstrap
+    #   make release
+
+    - name: analyze
+      uses: github/codeql-action/analyze@v2

.github.old/workflows/dependabot-automerge.yml

@@ -0,0 +1,27 @@
+name: "dependabot-automerge"
+
+on:
+  pull_request_target:
+    types: [assigned, opened, synchronize, reopened]
+
+permissions:
+  pull-requests: write
+  contents: write
+
+jobs:
+  automerge:
+    runs-on: ubuntu-latest
+    if: github.actor == 'dependabot[bot]'
+    steps:
+      - name: metadata
+        id: metadata
+        uses: dependabot/fetch-metadata@v1.3.6
+        with:
+          github-token: "${{ secrets.TOKEN }}"
+      - name: merge
+        id: merge
+        if: ${{contains(steps.metadata.outputs.dependency-names, 'go.unistack.org')}}
+        run: gh pr merge --auto --merge "$PR_URL"
+        env:
+          PR_URL: ${{github.event.pull_request.html_url}}
+          GITHUB_TOKEN: ${{secrets.TOKEN}}

.github.old/workflows/pr.yml

@@ -0,0 +1,40 @@
+name: prbuild
+on:
+  pull_request:
+    branches:
+    - master
+    - v3
+jobs:
+  test:
+    name: test
+    runs-on: ubuntu-latest
+    steps:
+    - name: setup
+      uses: actions/setup-go@v3
+      with:
+        go-version: 1.17
+    - name: checkout
+      uses: actions/checkout@v3
+    - name: cache
+      uses: actions/cache@v3
+      with:
+        path: ~/go/pkg/mod
+        key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
+        restore-keys: ${{ runner.os }}-go-
+    - name: deps
+      run: go get -v -t -d ./...
+    - name: test
+      env:
+        INTEGRATION_TESTS: yes
+      run: go test -mod readonly -v ./...
+  lint:
+    name: lint
+    runs-on: ubuntu-latest
+    steps:
+      - name: checkout
+        uses: actions/checkout@v3
+      - name: lint
+        uses: golangci/golangci-lint-action@v3.4.0
+        continue-on-error: true
+        with:
+          version: v1.30

.github/generate.sh

@@ -1,15 +0,0 @@
-#!/bin/bash -e
-
-find . -type f -name '*.pb.*.go' -o -name '*.pb.go' -a ! -name 'message.pb.go' -delete
-PROTOS=$(find . -type f -name '*.proto' | grep -v proto/google/api)
-
-mkdir -p proto/google/api
-curl -s -o proto/google/api/annotations.proto -L https://raw.githubusercontent.com/googleapis/googleapis/master/google/api/annotations.proto
-curl -s -o proto/google/api/http.proto -L https://raw.githubusercontent.com/googleapis/googleapis/master/google/api/http.proto
-
-for PROTO in $PROTOS; do
-  echo $PROTO
-  protoc -I./proto -I. -I$(dirname $PROTO) --go-grpc_out=paths=source_relative:. --go_out=paths=source_relative:. --micro_out=paths=source_relative:. $PROTO
-done
-
-rm -r proto

.github/renovate.json

@@ -1,20 +0,0 @@
-{
-  "extends": [
-    "config:base"
-  ],
-  "postUpdateOptions": ["gomodTidy"],
-  "packageRules": [
-    {
-      "matchUpdateTypes": ["minor", "patch", "pin", "digest"],
-      "automerge": true
-    },
-    {
-      "groupName": "all deps",
-      "separateMajorMinor": true,
-      "groupSlug": "all",
-      "packagePatterns": [
-        "*"
-      ]
-    }
-  ]
-}

.github/stale.sh

@@ -1,13 +0,0 @@
-#!/bin/bash -ex
-
-export PATH=$PATH:$(pwd)/bin
-export GO111MODULE=on
-export GOBIN=$(pwd)/bin
-
-#go get github.com/rvflash/goup@v0.4.1
-
-#goup -v ./...
-#go get github.com/psampaz/go-mod-outdated@v0.6.0
-go list -u -m -mod=mod -json all | go-mod-outdated -update -direct -ci || true
-
-#go list -u -m -json all | go-mod-outdated -update

.github/workflows/pr.yml

@@ -1,62 +0,0 @@
-name: prbuild
-on:
-  pull_request:
-    branches:
-    - master
-jobs:
-  test:
-    name: test
-    runs-on: ubuntu-latest
-    steps:
-    - name: setup
-      uses: actions/setup-go@v2
-      with:
-        go-version: 1.16
-    - name: cache
-      uses: actions/cache@v2
-      with:
-        path: ~/go/pkg
-        key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
-        restore-keys: ${{ runner.os }}-go-
-    - name: sdk checkout
-      uses: actions/checkout@v2
-    - name: sdk deps
-      run: go get -v -t -d ./...
-    - name: sdk test
-      env:
-        INTEGRATION_TESTS: yes
-      run: go test -mod readonly -v ./...
-    - name: tests checkout
-      uses: actions/checkout@v2
-      with:
-        repository: unistack-org/micro-tests
-        ref: refs/heads/master
-        path: micro-tests
-        fetch-depth: 1
-    - name: tests deps
-      run: |
-        cd micro-tests
-        go mod edit -replace="github.com/unistack-org/micro/v3=../"
-        go get -v -t -d ./...
-    - name: tests test
-      env:
-        INTEGRATION_TESTS: yes
-      run: cd micro-tests && go test -mod readonly -v ./...
-  lint:
-    name: lint
-    runs-on: ubuntu-latest
-    steps:
-      - name: checkout
-        uses: actions/checkout@v2
-      - name: lint
-        uses: golangci/golangci-lint-action@v2
-        continue-on-error: true
-        with:
-          # Required: the version of golangci-lint is required and must be specified without patch version: we always use the latest patch version.
-          version: v1.30
-          # Optional: working directory, useful for monorepos
-          # working-directory: somedir
-          # Optional: golangci-lint command line arguments.
-          # args: --issues-exit-code=0
-          # Optional: show only new issues if it's a pull request. The default value is `false`.
-          # only-new-issues: true

.gitignore

@@ -1,6 +1,8 @@
 # Develop tools
 /.vscode/
 /.idea/
+.idea
+.vscode
 
 # Binaries for programs and plugins
 *.exe
@@ -13,6 +15,7 @@
 _obj
 _test
 _build
+.DS_Store
 
 # Architecture specific extensions/prefixes
 *.[568vq]

.golangci.yml

@@ -1,30 +1,44 @@
 run:
+  concurrency: 4
   deadline: 5m
-  modules-download-mode: readonly
-  skip-files:
-    - ".*\\.pb\\.go$"
-    - ".*\\.pb\\.micro\\.go$"
+  issues-exit-code: 1
+  tests: true
+
+linters-settings:
+  govet:
+    check-shadowing: true
+    enable:
+      - fieldalignment
+
 linters:
-  disable-all: false
-  enable-all: false
   enable:
-    - megacheck
-    - staticcheck
-    - deadcode
-    - varcheck
-    - gosimple
-    - unused
-    - prealloc
-    - scopelint
-    - gocritic
-    - goimports
-    - unconvert
     - govet
-    - nakedret
+    - deadcode
+    - errcheck
+    - govet
+    - ineffassign
+    - staticcheck
     - structcheck
-    - gosec
-  disable:
-    - maligned
-    - interfacer
     - typecheck
-    - dupl
+    - unused
+    - varcheck
+    - bodyclose
+    - gci
+    - goconst
+    - gocritic
+    - gosimple
+    - gofmt
+    - gofumpt
+    - goimports
+    - revive
+    - gosec
+    - makezero
+    - misspell
+    - nakedret
+    - nestif
+    - nilerr
+    - noctx
+    - prealloc
+    - unconvert
+    - unparam
+  disable-all: false

README.md

@@ -1,4 +1,4 @@
-# Micro [![License](https://img.shields.io/:license-apache-blue.svg)](https://opensource.org/licenses/Apache-2.0) [![Doc](https://img.shields.io/badge/go.dev-reference-007d9c?logo=go&logoColor=white&style=flat-square)](https://pkg.go.dev/github.com/unistack-org/micro/v3?tab=overview) [![Status](https://github.com/unistack-org/micro/workflows/build/badge.svg?branch=master)](https://github.com/unistack-org/micro/actions?query=workflow%3Abuild+branch%3Amaster+event%3Apush) [![Lint](https://goreportcard.com/badge/github.com/unistack-org/micro)](https://goreportcard.com/report/github.com/unistack-org/micro) [![Slack](https://img.shields.io/static/v1?label=micro&message=slack&color=blueviolet)](https://unistack-org.slack.com/messages/default)
+# Micro [![License](https://img.shields.io/:license-apache-blue.svg)](https://opensource.org/licenses/Apache-2.0) [![Doc](https://img.shields.io/badge/go.dev-reference-007d9c?logo=go&logoColor=white&style=flat-square)](https://pkg.go.dev/github.com/unistack-org/micro/v3?tab=overview) [![Status](https://github.com/unistack-org/micro/workflows/build/badge.svg?branch=master)](https://github.com/unistack-org/micro/actions?query=workflow%3Abuild+branch%3Amaster+event%3Apush) [![Lint](https://goreportcard.com/badge/go.unistack.org/micro/v3)](https://goreportcard.com/report/go.unistack.org/micro/v3) [![Coverage](https://codecov.io/gh/unistack-org/micro/branch/v3/graph/badge.svg?token=OZPO2LP7VS)](https://codecov.io/gh/unistack-org/micro)
 
 Micro is a standard library for microservices.
 

SECURITY.md

@@ -0,0 +1,15 @@
+# Security Policy
+
+## Supported Versions
+
+Use this section to tell people about which versions of your project are
+currently being supported with security updates.
+
+| Version | Supported          |
+| ------- | ------------------ |
+| 3.7.x   | :white_check_mark: |
+| < 3.7.0 | :x:                |
+
+## Reporting a Vulnerability
+
+If you find any issue, please create github issue in this repo

api/api.go

@@ -1,181 +0,0 @@
-package api
-
-import (
-	"errors"
-	"regexp"
-	"strings"
-
-	"github.com/unistack-org/micro/v3/metadata"
-	"github.com/unistack-org/micro/v3/register"
-	"github.com/unistack-org/micro/v3/server"
-)
-
-// Api interface
-type Api interface {
-	// Initialise options
-	Init(...Option) error
-	// Get the options
-	Options() Options
-	// Register a http handler
-	Register(*Endpoint) error
-	// Register a route
-	Deregister(*Endpoint) error
-	// Implementation of api
-	String() string
-}
-
-// Options holds the options
-type Options struct{}
-
-// Option func signature
-type Option func(*Options) error
-
-// Endpoint is a mapping between an RPC method and HTTP endpoint
-type Endpoint struct {
-	// Name Greeter.Hello
-	Name string
-	// Description e.g what's this endpoint for
-	Description string
-	// Handler e.g rpc, proxy
-	Handler string
-	// Host e.g example.com
-	Host []string
-	// Method e.g GET, POST
-	Method []string
-	// Path e.g /greeter. Expect POSIX regex
-	Path []string
-	// Body destination
-	// "*" or "" - top level message value
-	// "string" - inner message value
-	Body string
-	// Stream flag
-	Stream bool
-}
-
-// Service represents an API service
-type Service struct {
-	// Name of service
-	Name string
-	// Endpoint for this service
-	Endpoint *Endpoint
-	// Services that provides service
-	Services []*register.Service
-}
-
-// Encode encodes an endpoint to endpoint metadata
-func Encode(e *Endpoint) map[string]string {
-	if e == nil {
-		return nil
-	}
-
-	// endpoint map
-	ep := make(map[string]string)
-
-	// set vals only if they exist
-	set := func(k, v string) {
-		if len(v) == 0 {
-			return
-		}
-		ep[k] = v
-	}
-
-	set("endpoint", e.Name)
-	set("description", e.Description)
-	set("handler", e.Handler)
-	set("method", strings.Join(e.Method, ","))
-	set("path", strings.Join(e.Path, ","))
-	set("host", strings.Join(e.Host, ","))
-	set("body", e.Body)
-
-	return ep
-}
-
-// Decode decodes endpoint metadata into an endpoint
-func Decode(e metadata.Metadata) *Endpoint {
-	if e == nil {
-		return nil
-	}
-
-	ep := &Endpoint{}
-	ep.Name, _ = e.Get("endpoint")
-	ep.Description, _ = e.Get("description")
-	epmethod, _ := e.Get("method")
-	ep.Method = []string{epmethod}
-	eppath, _ := e.Get("path")
-	ep.Path = []string{eppath}
-	ephost, _ := e.Get("host")
-	ep.Host = []string{ephost}
-	ep.Handler, _ = e.Get("handler")
-	ep.Body, _ = e.Get("body")
-
-	return ep
-}
-
-// Validate validates an endpoint to guarantee it won't blow up when being served
-func Validate(e *Endpoint) error {
-	if e == nil {
-		return errors.New("endpoint is nil")
-	}
-
-	if len(e.Name) == 0 {
-		return errors.New("name required")
-	}
-
-	for _, p := range e.Path {
-		ps := p[0]
-		pe := p[len(p)-1]
-
-		if ps == '^' && pe == '$' {
-			_, err := regexp.CompilePOSIX(p)
-			if err != nil {
-				return err
-			}
-		} else if ps == '^' && pe != '$' {
-			return errors.New("invalid path")
-		} else if ps != '^' && pe == '$' {
-			return errors.New("invalid path")
-		}
-	}
-
-	if len(e.Handler) == 0 {
-		return errors.New("invalid handler")
-	}
-
-	return nil
-}
-
-/*
-Design ideas
-
-// Gateway is an api gateway interface
-type Gateway interface {
-	// Register a http handler
-	Handle(pattern string, http.Handler)
-	// Register a route
-	RegisterRoute(r Route)
-	// Init initialises the command line.
-	// It also parses further options.
-	Init(...Option) error
-	// Run the gateway
-	Run() error
-}
-
-// NewGateway returns a new api gateway
-func NewGateway() Gateway {
-	return newGateway()
-}
-*/
-
-// WithEndpoint returns a server.HandlerOption with endpoint metadata set
-//
-// Usage:
-//
-// 	proto.RegisterHandler(service.Server(), new(Handler), api.WithEndpoint(
-//		&api.Endpoint{
-//			Name: "Greeter.Hello",
-//			Path: []string{"/greeter"},
-//		},
-//	))
-func WithEndpoint(e *Endpoint) server.HandlerOption {
-	return server.EndpointMetadata(e.Name, Encode(e))
-}

api/api_test.go

@@ -1,153 +0,0 @@
-package api
-
-import (
-	"strings"
-	"testing"
-)
-
-//nolint:gocyclo
-func TestEncoding(t *testing.T) {
-	testData := []*Endpoint{
-		nil,
-		{
-			Name:        "Foo.Bar",
-			Description: "A test endpoint",
-			Handler:     "meta",
-			Host:        []string{"foo.com"},
-			Method:      []string{"GET"},
-			Path:        []string{"/test"},
-		},
-	}
-
-	compare := func(expect, got []string) bool {
-		// no data to compare, return true
-		if len(expect) == 0 && len(got) == 0 {
-			return true
-		}
-		// no data expected but got some return false
-		if len(expect) == 0 && len(got) > 0 {
-			return false
-		}
-
-		// compare expected with what we got
-		for _, e := range expect {
-			var seen bool
-			for _, g := range got {
-				if e == g {
-					seen = true
-					break
-				}
-			}
-			if !seen {
-				return false
-			}
-		}
-
-		// we're done, return true
-		return true
-	}
-
-	for _, d := range testData {
-		// encode
-		e := Encode(d)
-		// decode
-		de := Decode(e)
-
-		// nil endpoint returns nil
-		if d == nil {
-			if e != nil {
-				t.Fatalf("expected nil got %v", e)
-			}
-			if de != nil {
-				t.Fatalf("expected nil got %v", de)
-			}
-
-			continue
-		}
-
-		// check encoded map
-		name := e["endpoint"]
-		desc := e["description"]
-		method := strings.Split(e["method"], ",")
-		path := strings.Split(e["path"], ",")
-		host := strings.Split(e["host"], ",")
-		handler := e["handler"]
-
-		if name != d.Name {
-			t.Fatalf("expected %v got %v", d.Name, name)
-		}
-		if desc != d.Description {
-			t.Fatalf("expected %v got %v", d.Description, desc)
-		}
-		if handler != d.Handler {
-			t.Fatalf("expected %v got %v", d.Handler, handler)
-		}
-		if ok := compare(d.Method, method); !ok {
-			t.Fatalf("expected %v got %v", d.Method, method)
-		}
-		if ok := compare(d.Path, path); !ok {
-			t.Fatalf("expected %v got %v", d.Path, path)
-		}
-		if ok := compare(d.Host, host); !ok {
-			t.Fatalf("expected %v got %v", d.Host, host)
-		}
-
-		if de.Name != d.Name {
-			t.Fatalf("expected %v got %v", d.Name, de.Name)
-		}
-		if de.Description != d.Description {
-			t.Fatalf("expected %v got %v", d.Description, de.Description)
-		}
-		if de.Handler != d.Handler {
-			t.Fatalf("expected %v got %v", d.Handler, de.Handler)
-		}
-		if ok := compare(d.Method, de.Method); !ok {
-			t.Fatalf("expected %v got %v", d.Method, de.Method)
-		}
-		if ok := compare(d.Path, de.Path); !ok {
-			t.Fatalf("expected %v got %v", d.Path, de.Path)
-		}
-		if ok := compare(d.Host, de.Host); !ok {
-			t.Fatalf("expected %v got %v", d.Host, de.Host)
-		}
-	}
-}
-
-func TestValidate(t *testing.T) {
-	epPcre := &Endpoint{
-		Name:        "Foo.Bar",
-		Description: "A test endpoint",
-		Handler:     "meta",
-		Host:        []string{"foo.com"},
-		Method:      []string{"GET"},
-		Path:        []string{"^/test/?$"},
-	}
-	if err := Validate(epPcre); err != nil {
-		t.Fatal(err)
-	}
-
-	epGpath := &Endpoint{
-		Name:        "Foo.Bar",
-		Description: "A test endpoint",
-		Handler:     "meta",
-		Host:        []string{"foo.com"},
-		Method:      []string{"GET"},
-		Path:        []string{"/test/{id}"},
-	}
-	if err := Validate(epGpath); err != nil {
-		t.Fatal(err)
-	}
-
-	epPcreInvalid := &Endpoint{
-		Name:        "Foo.Bar",
-		Description: "A test endpoint",
-		Handler:     "meta",
-		Host:        []string{"foo.com"},
-		Method:      []string{"GET"},
-		Path:        []string{"/test/?$"},
-	}
-	if err := Validate(epPcreInvalid); err == nil {
-		t.Fatalf("invalid pcre %v", epPcreInvalid.Path[0])
-	}
-
-}

api/handler/handler.go

@@ -1,14 +0,0 @@
-// Package handler provides http handlers
-package handler
-
-import (
-	"net/http"
-)
-
-// Handler represents a HTTP handler that manages a request
-type Handler interface {
-	// standard http handler
-	http.Handler
-	// name of handler
-	String() string
-}

api/handler/options.go

@@ -1,72 +0,0 @@
-package handler
-
-import (
-	"github.com/unistack-org/micro/v3/api/router"
-	"github.com/unistack-org/micro/v3/client"
-	"github.com/unistack-org/micro/v3/logger"
-)
-
-var (
-	// DefaultMaxRecvSize specifies max recv size for handler
-	DefaultMaxRecvSize int64 = 1024 * 1024 * 100 // 10Mb
-)
-
-// Options struct holds handler options
-type Options struct {
-	MaxRecvSize int64
-	Namespace   string
-	Router      router.Router
-	Client      client.Client
-	Logger      logger.Logger
-}
-
-// Option func signature
-type Option func(o *Options)
-
-// NewOptions creates new options struct and fills it
-func NewOptions(opts ...Option) Options {
-	options := Options{
-		Client:      client.DefaultClient,
-		Router:      router.DefaultRouter,
-		Logger:      logger.DefaultLogger,
-		MaxRecvSize: DefaultMaxRecvSize,
-	}
-	for _, o := range opts {
-		o(&options)
-	}
-
-	// set namespace if blank
-	if len(options.Namespace) == 0 {
-		WithNamespace("go.micro.api")(&options)
-	}
-
-	return options
-}
-
-// WithNamespace specifies the namespace for the handler
-func WithNamespace(s string) Option {
-	return func(o *Options) {
-		o.Namespace = s
-	}
-}
-
-// WithRouter specifies a router to be used by the handler
-func WithRouter(r router.Router) Option {
-	return func(o *Options) {
-		o.Router = r
-	}
-}
-
-// WithClient specifies client to be used by the handler
-func WithClient(c client.Client) Option {
-	return func(o *Options) {
-		o.Client = c
-	}
-}
-
-// WithMaxRecvSize specifies max body size
-func WithMaxRecvSize(size int64) Option {
-	return func(o *Options) {
-		o.MaxRecvSize = size
-	}
-}

api/resolver/grpc/grpc.go

@@ -1,47 +0,0 @@
-// Package grpc resolves a grpc service like /greeter.Say/Hello to greeter service
-package grpc
-
-import (
-	"errors"
-	"net/http"
-	"strings"
-
-	"github.com/unistack-org/micro/v3/api/resolver"
-)
-
-// Resolver struct
-type Resolver struct {
-	opts resolver.Options
-}
-
-// Resolve func to resolve enndpoint
-func (r *Resolver) Resolve(req *http.Request, opts ...resolver.ResolveOption) (*resolver.Endpoint, error) {
-	// parse options
-	options := resolver.NewResolveOptions(opts...)
-
-	// /foo.Bar/Service
-	if req.URL.Path == "/" {
-		return nil, errors.New("unknown name")
-	}
-	// [foo.Bar, Service]
-	parts := strings.Split(req.URL.Path[1:], "/")
-	// [foo, Bar]
-	name := strings.Split(parts[0], ".")
-	// foo
-	return &resolver.Endpoint{
-		Name:   strings.Join(name[:len(name)-1], "."),
-		Host:   req.Host,
-		Method: req.Method,
-		Path:   req.URL.Path,
-		Domain: options.Domain,
-	}, nil
-}
-
-func (r *Resolver) String() string {
-	return "grpc"
-}
-
-// NewResolver is used to create new Resolver
-func NewResolver(opts ...resolver.Option) resolver.Resolver {
-	return &Resolver{opts: resolver.NewOptions(opts...)}
-}

api/resolver/host/host.go

@@ -1,35 +0,0 @@
-// Package host resolves using http host
-package host
-
-import (
-	"net/http"
-
-	"github.com/unistack-org/micro/v3/api/resolver"
-)
-
-type hostResolver struct {
-	opts resolver.Options
-}
-
-// Resolve endpoint
-func (r *hostResolver) Resolve(req *http.Request, opts ...resolver.ResolveOption) (*resolver.Endpoint, error) {
-	// parse options
-	options := resolver.NewResolveOptions(opts...)
-
-	return &resolver.Endpoint{
-		Name:   req.Host,
-		Host:   req.Host,
-		Method: req.Method,
-		Path:   req.URL.Path,
-		Domain: options.Domain,
-	}, nil
-}
-
-func (r *hostResolver) String() string {
-	return "host"
-}
-
-// NewResolver creates new host api resolver
-func NewResolver(opts ...resolver.Option) resolver.Resolver {
-	return &hostResolver{opts: resolver.NewOptions(opts...)}
-}

api/resolver/options.go

@@ -1,67 +0,0 @@
-package resolver
-
-import (
-	"context"
-
-	"github.com/unistack-org/micro/v3/register"
-)
-
-// Options struct
-type Options struct {
-	Handler       string
-	ServicePrefix string
-	Context       context.Context
-}
-
-// Option func
-type Option func(o *Options)
-
-// WithHandler sets the handler being used
-func WithHandler(h string) Option {
-	return func(o *Options) {
-		o.Handler = h
-	}
-}
-
-// WithServicePrefix sets the ServicePrefix option
-func WithServicePrefix(p string) Option {
-	return func(o *Options) {
-		o.ServicePrefix = p
-	}
-}
-
-// NewOptions returns new initialised options
-func NewOptions(opts ...Option) Options {
-	options := Options{
-		Context: context.Background(),
-	}
-	for _, o := range opts {
-		o(&options)
-	}
-	return options
-}
-
-// ResolveOptions are used when resolving a request
-type ResolveOptions struct {
-	Domain string
-}
-
-// ResolveOption sets an option
-type ResolveOption func(*ResolveOptions)
-
-// Domain sets the resolve Domain option
-func Domain(n string) ResolveOption {
-	return func(o *ResolveOptions) {
-		o.Domain = n
-	}
-}
-
-// NewResolveOptions returns new initialised resolve options
-func NewResolveOptions(opts ...ResolveOption) ResolveOptions {
-	options := ResolveOptions{Domain: register.DefaultDomain}
-	for _, o := range opts {
-		o(&options)
-	}
-
-	return options
-}

api/resolver/path/path.go

@@ -1,44 +0,0 @@
-// Package path resolves using http path
-package path
-
-import (
-	"net/http"
-	"strings"
-
-	"github.com/unistack-org/micro/v3/api/resolver"
-)
-
-// Resolver the path resolver
-type Resolver struct {
-	opts resolver.Options
-}
-
-// Resolve resolves endpoint
-func (r *Resolver) Resolve(req *http.Request, opts ...resolver.ResolveOption) (*resolver.Endpoint, error) {
-	// parse options
-	options := resolver.NewResolveOptions(opts...)
-
-	if req.URL.Path == "/" {
-		return nil, resolver.ErrNotFound
-	}
-
-	parts := strings.Split(req.URL.Path[1:], "/")
-
-	return &resolver.Endpoint{
-		Name:   r.opts.ServicePrefix + "." + parts[0],
-		Host:   req.Host,
-		Method: req.Method,
-		Path:   req.URL.Path,
-		Domain: options.Domain,
-	}, nil
-}
-
-// String retruns the string representation
-func (r *Resolver) String() string {
-	return "path"
-}
-
-// NewResolver returns new path resolver
-func NewResolver(opts ...resolver.Option) resolver.Resolver {
-	return &Resolver{opts: resolver.NewOptions(opts...)}
-}

api/resolver/resolver.go

@@ -1,34 +0,0 @@
-// Package resolver resolves a http request to an endpoint
-package resolver
-
-import (
-	"errors"
-	"net/http"
-)
-
-var (
-	// ErrNotFound returned when endpoint is not found
-	ErrNotFound = errors.New("not found")
-	// ErrInvalidPath returned on invalid path
-	ErrInvalidPath = errors.New("invalid path")
-)
-
-// Resolver resolves requests to endpoints
-type Resolver interface {
-	Resolve(r *http.Request, opts ...ResolveOption) (*Endpoint, error)
-	String() string
-}
-
-// Endpoint is the endpoint for a http request
-type Endpoint struct {
-	// Endpoint name e.g greeter
-	Name string
-	// HTTP Host e.g example.com
-	Host string
-	// HTTP Methods e.g GET, POST
-	Method string
-	// HTTP Path e.g /greeter.
-	Path string
-	// Domain endpoint exists within
-	Domain string
-}

api/resolver/subdomain/subdomain.go

@@ -1,90 +0,0 @@
-// Package subdomain is a resolver which uses the subdomain to determine the domain to route to. It
-// offloads the endpoint resolution to a child resolver which is provided in New.
-package subdomain
-
-import (
-	"net"
-	"net/http"
-	"strings"
-
-	"github.com/unistack-org/micro/v3/api/resolver"
-	"github.com/unistack-org/micro/v3/logger"
-	"golang.org/x/net/publicsuffix"
-)
-
-// NewResolver creates new subdomain api resolver
-func NewResolver(parent resolver.Resolver, opts ...resolver.Option) resolver.Resolver {
-	options := resolver.NewOptions(opts...)
-	return &subdomainResolver{options, parent}
-}
-
-type subdomainResolver struct {
-	opts resolver.Options
-	resolver.Resolver
-}
-
-// Resolve resolve endpoint based on subdomain
-func (r *subdomainResolver) Resolve(req *http.Request, opts ...resolver.ResolveOption) (*resolver.Endpoint, error) {
-	if dom := r.Domain(req); len(dom) > 0 {
-		opts = append(opts, resolver.Domain(dom))
-	}
-
-	return r.Resolver.Resolve(req, opts...)
-}
-
-// Domain returns domain
-func (r *subdomainResolver) Domain(req *http.Request) string {
-	// determine the host, e.g. foobar.m3o.app
-	host := req.URL.Hostname()
-	if len(host) == 0 {
-		if h, _, err := net.SplitHostPort(req.Host); err == nil {
-			host = h // host does contain a port
-		} else if strings.Contains(err.Error(), "missing port in address") {
-			host = req.Host // host does not contain a port
-		}
-	}
-
-	// check for an ip address
-	if net.ParseIP(host) != nil {
-		return ""
-	}
-
-	// check for dev environment
-	if host == "localhost" || host == "127.0.0.1" {
-		return ""
-	}
-
-	// extract the top level domain plus one (e.g. 'myapp.com')
-	domain, err := publicsuffix.EffectiveTLDPlusOne(host)
-	if err != nil {
-		if logger.V(logger.DebugLevel) {
-			logger.Debug(r.opts.Context, "Unable to extract domain from %v", host)
-		}
-		return ""
-	}
-
-	// there was no subdomain
-	if host == domain {
-		return ""
-	}
-
-	// remove the domain from the host, leaving the subdomain, e.g. "staging.foo.myapp.com" => "staging.foo"
-	subdomain := strings.TrimSuffix(host, "."+domain)
-
-	// ignore the API subdomain
-	if subdomain == "api" {
-		return ""
-	}
-
-	// return the reversed subdomain as the namespace, e.g. "staging.foo" => "foo-staging"
-	comps := strings.Split(subdomain, ".")
-	for i := len(comps)/2 - 1; i >= 0; i-- {
-		opp := len(comps) - 1 - i
-		comps[i], comps[opp] = comps[opp], comps[i]
-	}
-	return strings.Join(comps, "-")
-}
-
-func (r *subdomainResolver) String() string {
-	return "subdomain"
-}

api/resolver/subdomain/subdomain_test.go

@@ -1,73 +0,0 @@
-package subdomain
-
-import (
-	"net/http"
-	"net/url"
-	"testing"
-
-	"github.com/unistack-org/micro/v3/api/resolver/vpath"
-)
-
-func TestResolve(t *testing.T) {
-	tt := []struct {
-		Name   string
-		Host   string
-		Result string
-	}{
-		{
-			Name:   "Top level domain",
-			Host:   "micro.mu",
-			Result: "micro",
-		},
-		{
-			Name:   "Effective top level domain",
-			Host:   "micro.com.au",
-			Result: "micro",
-		},
-		{
-			Name:   "Subdomain dev",
-			Host:   "dev.micro.mu",
-			Result: "dev",
-		},
-		{
-			Name:   "Subdomain foo",
-			Host:   "foo.micro.mu",
-			Result: "foo",
-		},
-		{
-			Name:   "Multi-level subdomain",
-			Host:   "staging.myapp.m3o.app",
-			Result: "myapp-staging",
-		},
-		{
-			Name:   "Dev host",
-			Host:   "127.0.0.1",
-			Result: "micro",
-		},
-		{
-			Name:   "Localhost",
-			Host:   "localhost",
-			Result: "micro",
-		},
-		{
-			Name:   "IP host",
-			Host:   "81.151.101.146",
-			Result: "micro",
-		},
-	}
-
-	for _, tc := range tt {
-		t.Run(tc.Name, func(t *testing.T) {
-			r := NewResolver(vpath.NewResolver())
-			result, err := r.Resolve(&http.Request{URL: &url.URL{Host: tc.Host, Path: "foo/bar"}})
-			if err != nil {
-				t.Fatal(err)
-			}
-			if result != nil {
-				if tc.Result != result.Domain {
-					t.Fatalf("Expected %v but got %v", tc.Result, result.Domain)
-				}
-			}
-		})
-	}
-}

api/resolver/vpath/vpath.go

@@ -1,77 +0,0 @@
-// Package vpath resolves using http path and recognised versioned urls
-package vpath
-
-import (
-	"errors"
-	"net/http"
-	"regexp"
-	"strings"
-
-	"github.com/unistack-org/micro/v3/api/resolver"
-)
-
-// NewResolver creates new vpath api resolver
-func NewResolver(opts ...resolver.Option) resolver.Resolver {
-	return &vpathResolver{opts: resolver.NewOptions(opts...)}
-}
-
-type vpathResolver struct {
-	opts resolver.Options
-}
-
-var (
-	re = regexp.MustCompile("^v[0-9]+$")
-)
-
-// Resolve endpoint
-func (r *vpathResolver) Resolve(req *http.Request, opts ...resolver.ResolveOption) (*resolver.Endpoint, error) {
-	if req.URL.Path == "/" {
-		return nil, errors.New("unknown name")
-	}
-
-	options := resolver.NewResolveOptions(opts...)
-
-	parts := strings.Split(req.URL.Path[1:], "/")
-	if len(parts) == 1 {
-		return &resolver.Endpoint{
-			Name:   r.withPrefix(parts...),
-			Host:   req.Host,
-			Method: req.Method,
-			Path:   req.URL.Path,
-			Domain: options.Domain,
-		}, nil
-	}
-
-	// /v1/foo
-	if re.MatchString(parts[0]) {
-		return &resolver.Endpoint{
-			Name:   r.withPrefix(parts[0:2]...),
-			Host:   req.Host,
-			Method: req.Method,
-			Path:   req.URL.Path,
-			Domain: options.Domain,
-		}, nil
-	}
-
-	return &resolver.Endpoint{
-		Name:   r.withPrefix(parts[0]),
-		Host:   req.Host,
-		Method: req.Method,
-		Path:   req.URL.Path,
-		Domain: options.Domain,
-	}, nil
-}
-
-func (r *vpathResolver) String() string {
-	return "vpath"
-}
-
-// withPrefix transforms "foo" into "go.micro.api.foo"
-func (r *vpathResolver) withPrefix(parts ...string) string {
-	p := r.opts.ServicePrefix
-	if len(p) > 0 {
-		parts = append([]string{p}, parts...)
-	}
-
-	return strings.Join(parts, ".")
-}

api/router/options.go

@@ -1,70 +0,0 @@
-package router
-
-import (
-	"context"
-
-	"github.com/unistack-org/micro/v3/api/resolver"
-	"github.com/unistack-org/micro/v3/api/resolver/vpath"
-	"github.com/unistack-org/micro/v3/logger"
-	"github.com/unistack-org/micro/v3/register"
-)
-
-// Options holds the options for api router
-type Options struct {
-	Handler  string
-	Register register.Register
-	Resolver resolver.Resolver
-	Logger   logger.Logger
-	Context  context.Context
-}
-
-// Option func signature
-type Option func(o *Options)
-
-// NewOptions returns options struct filled by opts
-func NewOptions(opts ...Option) Options {
-	options := Options{
-		Context: context.Background(),
-		Handler: "meta",
-	}
-
-	for _, o := range opts {
-		o(&options)
-	}
-
-	if options.Resolver == nil {
-		options.Resolver = vpath.NewResolver(
-			resolver.WithHandler(options.Handler),
-		)
-	}
-
-	return options
-}
-
-// WithContext sets the context
-func WithContext(ctx context.Context) Option {
-	return func(o *Options) {
-		o.Context = ctx
-	}
-}
-
-// WithHandler sets the handler
-func WithHandler(h string) Option {
-	return func(o *Options) {
-		o.Handler = h
-	}
-}
-
-// WithRegister sets the register
-func WithRegister(r register.Register) Option {
-	return func(o *Options) {
-		o.Register = r
-	}
-}
-
-// WithResolver sets the resolver
-func WithResolver(r resolver.Resolver) Option {
-	return func(o *Options) {
-		o.Resolver = r
-	}
-}

api/router/router.go

@@ -1,33 +0,0 @@
-// Package router provides api service routing
-package router
-
-import (
-	"net/http"
-
-	"github.com/unistack-org/micro/v3/api"
-)
-
-var (
-	// DefaultRouter contains default router implementation
-	DefaultRouter Router
-)
-
-// Router is used to determine an endpoint for a request
-type Router interface {
-	// Returns options
-	Options() Options
-	// Init initialize router
-	Init(...Option) error
-	// Stop the router
-	Close() error
-	// Endpoint returns an api.Service endpoint or an error if it does not exist
-	Endpoint(r *http.Request) (*api.Service, error)
-	// Register endpoint in router
-	Register(ep *api.Endpoint) error
-	// Deregister endpoint from router
-	Deregister(ep *api.Endpoint) error
-	// Route returns an api.Service route
-	Route(r *http.Request) (*api.Service, error)
-	// String representation of router
-	String() string
-}

auth/auth.go

@@ -1,143 +0,0 @@
-// Package auth provides authentication and authorization capability
-package auth
-
-import (
-	"context"
-	"errors"
-	"time"
-
-	"github.com/unistack-org/micro/v3/metadata"
-)
-
-const (
-	// BearerScheme used for Authorization header
-	BearerScheme = "Bearer "
-	// ScopePublic is the scope applied to a rule to allow access to the public
-	ScopePublic = ""
-	// ScopeAccount is the scope applied to a rule to limit to users with any valid account
-	ScopeAccount = "*"
-)
-
-var (
-	// DefaultAuth holds default auth implementation
-	DefaultAuth Auth = NewAuth()
-	// ErrInvalidToken is when the token provided is not valid
-	ErrInvalidToken = errors.New("invalid token provided")
-	// ErrForbidden is when a user does not have the necessary scope to access a resource
-	ErrForbidden = errors.New("resource forbidden")
-)
-
-// Auth provides authentication and authorization
-type Auth interface {
-	// Init the auth
-	Init(opts ...Option)
-	// Options set for auth
-	Options() Options
-	// Generate a new account
-	Generate(id string, opts ...GenerateOption) (*Account, error)
-	// Verify an account has access to a resource using the rules
-	Verify(acc *Account, res *Resource, opts ...VerifyOption) error
-	// Inspect a token
-	Inspect(token string) (*Account, error)
-	// Token generated using refresh token or credentials
-	Token(opts ...TokenOption) (*Token, error)
-	// Grant access to a resource
-	Grant(rule *Rule) error
-	// Revoke access to a resource
-	Revoke(rule *Rule) error
-	// Rules returns all the rules used to verify requests
-	Rules(...RulesOption) ([]*Rule, error)
-	// String returns the name of the implementation
-	String() string
-}
-
-// Account provided by an auth provider
-type Account struct {
-	// ID of the account e.g. email
-	ID string `json:"id"`
-	// Type of the account, e.g. service
-	Type string `json:"type"`
-	// Issuer of the account
-	Issuer string `json:"issuer"`
-	// Any other associated metadata
-	Metadata metadata.Metadata `json:"metadata"`
-	// Scopes the account has access to
-	Scopes []string `json:"scopes"`
-	// Secret for the account, e.g. the password
-	Secret string `json:"secret"`
-}
-
-// Token can be short or long lived
-type Token struct {
-	// The token to be used for accessing resources
-	AccessToken string `json:"access_token"`
-	// RefreshToken to be used to generate a new token
-	RefreshToken string `json:"refresh_token"`
-	// Time of token creation
-	Created time.Time `json:"created"`
-	// Time of token expiry
-	Expiry time.Time `json:"expiry"`
-}
-
-// Expired returns a boolean indicating if the token needs to be refreshed
-func (t *Token) Expired() bool {
-	return t.Expiry.Unix() < time.Now().Unix()
-}
-
-// Resource is an entity such as a user or
-type Resource struct {
-	// Name of the resource, e.g. go.micro.service.notes
-	Name string `json:"name"`
-	// Type of resource, e.g. service
-	Type string `json:"type"`
-	// Endpoint resource e.g NotesService.Create
-	Endpoint string `json:"endpoint"`
-}
-
-// Access defines the type of access a rule grants
-type Access int
-
-const (
-	// AccessGranted to a resource
-	AccessGranted Access = iota
-	// AccessDenied to a resource
-	AccessDenied
-)
-
-// Rule is used to verify access to a resource
-type Rule struct {
-	// ID of the rule, e.g. "public"
-	ID string
-	// Scope the rule requires, a blank scope indicates open to the public and * indicates the rule
-	// applies to any valid account
-	Scope string
-	// Resource the rule applies to
-	Resource *Resource
-	// Access determines if the rule grants or denies access to the resource
-	Access Access
-	// Priority the rule should take when verifying a request, the higher the value the sooner the
-	// rule will be applied
-	Priority int32
-}
-
-type accountKey struct{}
-
-// AccountFromContext gets the account from the context, which
-// is set by the auth wrapper at the start of a call. If the account
-// is not set, a nil account will be returned. The error is only returned
-// when there was a problem retrieving an account
-func AccountFromContext(ctx context.Context) (*Account, bool) {
-	if ctx == nil {
-		return nil, false
-	}
-	acc, ok := ctx.Value(accountKey{}).(*Account)
-	return acc, ok
-}
-
-// ContextWithAccount sets the account in the context
-func ContextWithAccount(ctx context.Context, account *Account) context.Context {
-	if ctx == nil {
-		ctx = context.Background()
-	}
-	return context.WithValue(ctx, accountKey{}, account)
-}

auth/noop.go

@@ -1,78 +0,0 @@
-package auth
-
-import (
-	"github.com/google/uuid"
-)
-
-type noopAuth struct {
-	opts Options
-}
-
-// String returns the name of the implementation
-func (n *noopAuth) String() string {
-	return "noop"
-}
-
-// Init the auth
-func (n *noopAuth) Init(opts ...Option) {
-	for _, o := range opts {
-		o(&n.opts)
-	}
-}
-
-// Options set for auth
-func (n *noopAuth) Options() Options {
-	return n.opts
-}
-
-// Generate a new account
-func (n *noopAuth) Generate(id string, opts ...GenerateOption) (*Account, error) {
-	options := NewGenerateOptions(opts...)
-
-	return &Account{
-		ID:       id,
-		Secret:   options.Secret,
-		Metadata: options.Metadata,
-		Scopes:   options.Scopes,
-		Issuer:   n.Options().Issuer,
-	}, nil
-}
-
-// Grant access to a resource
-func (n *noopAuth) Grant(rule *Rule) error {
-	return nil
-}
-
-// Revoke access to a resource
-func (n *noopAuth) Revoke(rule *Rule) error {
-	return nil
-}
-
-// Rules used to verify requests
-func (n *noopAuth) Rules(opts ...RulesOption) ([]*Rule, error) {
-	return []*Rule{}, nil
-}
-
-// Verify an account has access to a resource
-func (n *noopAuth) Verify(acc *Account, res *Resource, opts ...VerifyOption) error {
-	return nil
-}
-
-// Inspect a token
-func (n *noopAuth) Inspect(token string) (*Account, error) {
-	uid, err := uuid.NewRandom()
-	if err != nil {
-		return nil, err
-	}
-	return &Account{ID: uid.String(), Issuer: n.Options().Issuer}, nil
-}
-
-// Token generation using an account id and secret
-func (n *noopAuth) Token(opts ...TokenOption) (*Token, error) {
-	return &Token{}, nil
-}
-
-// NewAuth returns new noop auth
-func NewAuth(opts ...Option) Auth {
-	return &noopAuth{opts: NewOptions(opts...)}
-}

auth/options.go

@@ -1,321 +0,0 @@
-package auth
-
-import (
-	"context"
-	"time"
-
-	"github.com/unistack-org/micro/v3/logger"
-	"github.com/unistack-org/micro/v3/metadata"
-	"github.com/unistack-org/micro/v3/meter"
-	"github.com/unistack-org/micro/v3/store"
-	"github.com/unistack-org/micro/v3/tracer"
-)
-
-// NewOptions creates Options struct from slice of options
-func NewOptions(opts ...Option) Options {
-	options := Options{
-		Tracer: tracer.DefaultTracer,
-		Logger: logger.DefaultLogger,
-		Meter:  meter.DefaultMeter,
-	}
-	for _, o := range opts {
-		o(&options)
-	}
-	return options
-}
-
-// Options struct holds auth options
-type Options struct {
-	Name string
-	// Issuer of the service's account
-	Issuer string
-	// ID is the services auth ID
-	ID string
-	// Secret is used to authenticate the service
-	Secret string
-	// Token is the services token used to authenticate itself
-	Token *Token
-	// PublicKey for decoding JWTs
-	PublicKey string
-	// PrivateKey for encoding JWTs
-	PrivateKey string
-	// LoginURL is the relative url path where a user can login
-	LoginURL string
-	// Store to back auth
-	Store store.Store
-	// Addrs sets the addresses of auth
-	Addrs []string
-	// Logger sets the logger
-	Logger logger.Logger
-	// Meter sets tht meter
-	Meter meter.Meter
-	// Tracer
-	Tracer tracer.Tracer
-	// Context to store other options
-	Context context.Context
-}
-
-// Option func
-type Option func(o *Options)
-
-// Addrs is the auth addresses to use
-func Addrs(addrs ...string) Option {
-	return func(o *Options) {
-		o.Addrs = addrs
-	}
-}
-
-// Name sets the name
-func Name(n string) Option {
-	return func(o *Options) {
-		o.Name = n
-	}
-}
-
-// Issuer of the services account
-func Issuer(i string) Option {
-	return func(o *Options) {
-		o.Issuer = i
-	}
-}
-
-// Store to back auth
-func Store(s store.Store) Option {
-	return func(o *Options) {
-		o.Store = s
-	}
-}
-
-// PublicKey is the JWT public key
-func PublicKey(key string) Option {
-	return func(o *Options) {
-		o.PublicKey = key
-	}
-}
-
-// PrivateKey is the JWT private key
-func PrivateKey(key string) Option {
-	return func(o *Options) {
-		o.PrivateKey = key
-	}
-}
-
-// Credentials sets the auth credentials
-func Credentials(id, secret string) Option {
-	return func(o *Options) {
-		o.ID = id
-		o.Secret = secret
-	}
-}
-
-// ClientToken sets the auth token to use when making requests
-func ClientToken(token *Token) Option {
-	return func(o *Options) {
-		o.Token = token
-	}
-}
-
-// LoginURL sets the auth LoginURL
-func LoginURL(url string) Option {
-	return func(o *Options) {
-		o.LoginURL = url
-	}
-}
-
-// GenerateOptions struct
-type GenerateOptions struct {
-	// Metadata associated with the account
-	Metadata metadata.Metadata
-	// Scopes the account has access too
-	Scopes []string
-	// Provider of the account, e.g. oauth
-	Provider string
-	// Type of the account, e.g. user
-	Type string
-	// Secret used to authenticate the account
-	Secret string
-	// Issuer of the account, e.g. micro
-	Issuer string
-}
-
-// GenerateOption func
-type GenerateOption func(o *GenerateOptions)
-
-// WithSecret for the generated account
-func WithSecret(s string) GenerateOption {
-	return func(o *GenerateOptions) {
-		o.Secret = s
-	}
-}
-
-// WithType for the generated account
-func WithType(t string) GenerateOption {
-	return func(o *GenerateOptions) {
-		o.Type = t
-	}
-}
-
-// WithMetadata for the generated account
-func WithMetadata(md metadata.Metadata) GenerateOption {
-	return func(o *GenerateOptions) {
-		o.Metadata = metadata.Copy(md)
-	}
-}
-
-// WithProvider for the generated account
-func WithProvider(p string) GenerateOption {
-	return func(o *GenerateOptions) {
-		o.Provider = p
-	}
-}
-
-// WithScopes for the generated account
-func WithScopes(s ...string) GenerateOption {
-	return func(o *GenerateOptions) {
-		o.Scopes = s
-	}
-}
-
-// WithIssuer for the generated account
-func WithIssuer(i string) GenerateOption {
-	return func(o *GenerateOptions) {
-		o.Issuer = i
-	}
-}
-
-// NewGenerateOptions from a slice of options
-func NewGenerateOptions(opts ...GenerateOption) GenerateOptions {
-	var options GenerateOptions
-	for _, o := range opts {
-		o(&options)
-	}
-	return options
-}
-
-// TokenOptions struct
-type TokenOptions struct {
-	// ID for the account
-	ID string
-	// Secret for the account
-	Secret string
-	// RefreshToken is used to refesh a token
-	RefreshToken string
-	// Expiry is the time the token should live for
-	Expiry time.Duration
-	// Issuer of the account
-	Issuer string
-}
-
-// TokenOption func
-type TokenOption func(o *TokenOptions)
-
-// WithExpiry for the token
-func WithExpiry(ex time.Duration) TokenOption {
-	return func(o *TokenOptions) {
-		o.Expiry = ex
-	}
-}
-
-// WithCredentials sets tye id and secret
-func WithCredentials(id, secret string) TokenOption {
-	return func(o *TokenOptions) {
-		o.ID = id
-		o.Secret = secret
-	}
-}
-
-// WithToken sets the refresh token
-func WithToken(rt string) TokenOption {
-	return func(o *TokenOptions) {
-		o.RefreshToken = rt
-	}
-}
-
-// WithTokenIssuer sets the token issuer option
-func WithTokenIssuer(iss string) TokenOption {
-	return func(o *TokenOptions) {
-		o.Issuer = iss
-	}
-}
-
-// NewTokenOptions from a slice of options
-func NewTokenOptions(opts ...TokenOption) TokenOptions {
-	var options TokenOptions
-	for _, o := range opts {
-		o(&options)
-	}
-
-	// set default expiry of token
-	if options.Expiry == 0 {
-		options.Expiry = time.Minute
-	}
-
-	return options
-}
-
-// VerifyOptions struct
-type VerifyOptions struct {
-	Context   context.Context
-	Namespace string
-}
-
-// VerifyOption func
-type VerifyOption func(o *VerifyOptions)
-
-// VerifyContext pass context to verify
-func VerifyContext(ctx context.Context) VerifyOption {
-	return func(o *VerifyOptions) {
-		o.Context = ctx
-	}
-}
-
-// VerifyNamespace sets thhe namespace for verify
-func VerifyNamespace(ns string) VerifyOption {
-	return func(o *VerifyOptions) {
-		o.Namespace = ns
-	}
-}
-
-// RulesOptions struct
-type RulesOptions struct {
-	Context   context.Context
-	Namespace string
-}
-
-// RulesOption func
-type RulesOption func(o *RulesOptions)
-
-// RulesContext pass rules context
-func RulesContext(ctx context.Context) RulesOption {
-	return func(o *RulesOptions) {
-		o.Context = ctx
-	}
-}
-
-// RulesNamespace sets the rule namespace
-func RulesNamespace(ns string) RulesOption {
-	return func(o *RulesOptions) {
-		o.Namespace = ns
-	}
-}
-
-// Logger sets the logger
-func Logger(l logger.Logger) Option {
-	return func(o *Options) {
-		o.Logger = l
-	}
-}
-
-// Meter sets the meter
-func Meter(m meter.Meter) Option {
-	return func(o *Options) {
-		o.Meter = m
-	}
-}
-
-// Tracer sets the meter
-func Tracer(t tracer.Tracer) Option {
-	return func(o *Options) {
-		o.Tracer = t
-	}
-}

auth/rules.go

@@ -1,92 +0,0 @@
-package auth
-
-import (
-	"fmt"
-	"sort"
-	"strings"
-)
-
-// VerifyAccess an account has access to a resource using the rules provided. If the account does not have
-// access an error will be returned. If there are no rules provided which match the resource, an error
-// will be returned
-//nolint:gocyclo
-func VerifyAccess(rules []*Rule, acc *Account, res *Resource) error {
-	// the rule is only to be applied if the type matches the resource or is catch-all (*)
-	validTypes := []string{"*", res.Type}
-
-	// the rule is only to be applied if the name matches the resource or is catch-all (*)
-	validNames := []string{"*", res.Name}
-
-	// rules can have wildcard excludes on endpoints since this can also be a path for web services,
-	// e.g. /foo/* would include /foo/bar. We also want to check for wildcards and the exact endpoint
-	validEndpoints := []string{"*", res.Endpoint}
-	if comps := strings.Split(res.Endpoint, "/"); len(comps) > 1 {
-		for i := 1; i < len(comps)+1; i++ {
-			wildcard := fmt.Sprintf("%v/*", strings.Join(comps[0:i], "/"))
-			validEndpoints = append(validEndpoints, wildcard)
-		}
-	}
-
-	// filter the rules to the ones which match the criteria above
-	filteredRules := make([]*Rule, 0)
-	for _, rule := range rules {
-		if !include(validTypes, rule.Resource.Type) {
-			continue
-		}
-		if !include(validNames, rule.Resource.Name) {
-			continue
-		}
-		if !include(validEndpoints, rule.Resource.Endpoint) {
-			continue
-		}
-		filteredRules = append(filteredRules, rule)
-	}
-
-	// sort the filtered rules by priority, highest to lowest
-	sort.SliceStable(filteredRules, func(i, j int) bool {
-		return filteredRules[i].Priority > filteredRules[j].Priority
-	})
-
-	// loop through the rules and check for a rule which applies to this account
-	for _, rule := range filteredRules {
-		// a blank scope indicates the rule applies to everyone, even nil accounts
-		if rule.Scope == ScopePublic && rule.Access == AccessDenied {
-			return ErrForbidden
-		} else if rule.Scope == ScopePublic && rule.Access == AccessGranted {
-			return nil
-		}
-
-		// all further checks require an account
-		if acc == nil {
-			continue
-		}
-
-		// this rule applies to any account
-		if rule.Scope == ScopeAccount && rule.Access == AccessDenied {
-			return ErrForbidden
-		} else if rule.Scope == ScopeAccount && rule.Access == AccessGranted {
-			return nil
-		}
-
-		// if the account has the necessary scope
-		if include(acc.Scopes, rule.Scope) && rule.Access == AccessDenied {
-			return ErrForbidden
-		} else if include(acc.Scopes, rule.Scope) && rule.Access == AccessGranted {
-			return nil
-		}
-	}
-
-	// if no rules matched then return forbidden
-	return ErrForbidden
-}
-
-// include is a helper function which checks to see if the slice contains the value. includes is
-// not case sensitive.
-func include(slice []string, val string) bool {
-	for _, s := range slice {
-		if strings.EqualFold(s, val) {
-			return true
-		}
-	}
-	return false
-}

auth/rules_test.go

@@ -1,288 +0,0 @@
-package auth
-
-import (
-	"testing"
-)
-
-func TestVerify(t *testing.T) {
-	srvResource := &Resource{
-		Type:     "service",
-		Name:     "go.micro.service.foo",
-		Endpoint: "Foo.Bar",
-	}
-
-	webResource := &Resource{
-		Type:     "service",
-		Name:     "go.micro.web.foo",
-		Endpoint: "/foo/bar",
-	}
-
-	catchallResource := &Resource{
-		Type:     "*",
-		Name:     "*",
-		Endpoint: "*",
-	}
-
-	tt := []struct {
-		Name     string
-		Rules    []*Rule
-		Account  *Account
-		Resource *Resource
-		Error    error
-	}{
-		{
-			Name:     "NoRules",
-			Rules:    []*Rule{},
-			Account:  nil,
-			Resource: srvResource,
-			Error:    ErrForbidden,
-		},
-		{
-			Name:     "CatchallPublicAccount",
-			Account:  &Account{},
-			Resource: srvResource,
-			Rules: []*Rule{
-				{
-					Scope:    "",
-					Resource: catchallResource,
-				},
-			},
-		},
-		{
-			Name:     "CatchallPublicNoAccount",
-			Resource: srvResource,
-			Rules: []*Rule{
-				{
-					Scope:    "",
-					Resource: catchallResource,
-				},
-			},
-		},
-		{
-			Name:     "CatchallPrivateAccount",
-			Account:  &Account{},
-			Resource: srvResource,
-			Rules: []*Rule{
-				{
-					Scope:    "*",
-					Resource: catchallResource,
-				},
-			},
-		},
-		{
-			Name:     "CatchallPrivateNoAccount",
-			Resource: srvResource,
-			Rules: []*Rule{
-				{
-					Scope:    "*",
-					Resource: catchallResource,
-				},
-			},
-			Error: ErrForbidden,
-		},
-		{
-			Name:     "CatchallServiceRuleMatch",
-			Resource: srvResource,
-			Account:  &Account{},
-			Rules: []*Rule{
-				{
-					Scope: "*",
-					Resource: &Resource{
-						Type:     srvResource.Type,
-						Name:     srvResource.Name,
-						Endpoint: "*",
-					},
-				},
-			},
-		},
-		{
-			Name:     "CatchallServiceRuleNoMatch",
-			Resource: srvResource,
-			Account:  &Account{},
-			Rules: []*Rule{
-				{
-					Scope: "*",
-					Resource: &Resource{
-						Type:     srvResource.Type,
-						Name:     "wrongname",
-						Endpoint: "*",
-					},
-				},
-			},
-			Error: ErrForbidden,
-		},
-		{
-			Name:     "ExactRuleValidScope",
-			Resource: srvResource,
-			Account: &Account{
-				Scopes: []string{"neededscope"},
-			},
-			Rules: []*Rule{
-				{
-					Scope:    "neededscope",
-					Resource: srvResource,
-				},
-			},
-		},
-		{
-			Name:     "ExactRuleInvalidScope",
-			Resource: srvResource,
-			Account: &Account{
-				Scopes: []string{"neededscope"},
-			},
-			Rules: []*Rule{
-				{
-					Scope:    "invalidscope",
-					Resource: srvResource,
-				},
-			},
-			Error: ErrForbidden,
-		},
-		{
-			Name:     "CatchallDenyWithAccount",
-			Resource: srvResource,
-			Account:  &Account{},
-			Rules: []*Rule{
-				{
-					Scope:    "*",
-					Resource: catchallResource,
-					Access:   AccessDenied,
-				},
-			},
-			Error: ErrForbidden,
-		},
-		{
-			Name:     "CatchallDenyWithNoAccount",
-			Resource: srvResource,
-			Account:  &Account{},
-			Rules: []*Rule{
-				{
-					Scope:    "*",
-					Resource: catchallResource,
-					Access:   AccessDenied,
-				},
-			},
-			Error: ErrForbidden,
-		},
-		{
-			Name:     "RulePriorityGrantFirst",
-			Resource: srvResource,
-			Account:  &Account{},
-			Rules: []*Rule{
-				{
-					Scope:    "*",
-					Resource: catchallResource,
-					Access:   AccessGranted,
-					Priority: 1,
-				},
-				{
-					Scope:    "*",
-					Resource: catchallResource,
-					Access:   AccessDenied,
-					Priority: 0,
-				},
-			},
-		},
-		{
-			Name:     "RulePriorityDenyFirst",
-			Resource: srvResource,
-			Account:  &Account{},
-			Rules: []*Rule{
-				{
-					Scope:    "*",
-					Resource: catchallResource,
-					Access:   AccessGranted,
-					Priority: 0,
-				},
-				{
-					Scope:    "*",
-					Resource: catchallResource,
-					Access:   AccessDenied,
-					Priority: 1,
-				},
-			},
-			Error: ErrForbidden,
-		},
-		{
-			Name:     "WebExactEndpointValid",
-			Resource: webResource,
-			Account:  &Account{},
-			Rules: []*Rule{
-				{
-					Scope:    "*",
-					Resource: webResource,
-				},
-			},
-		},
-		{
-			Name:     "WebExactEndpointInalid",
-			Resource: webResource,
-			Account:  &Account{},
-			Rules: []*Rule{
-				{
-					Scope: "*",
-					Resource: &Resource{
-						Type:     webResource.Type,
-						Name:     webResource.Name,
-						Endpoint: "invalidendpoint",
-					},
-				},
-			},
-			Error: ErrForbidden,
-		},
-		{
-			Name:     "WebWildcardEndpoint",
-			Resource: webResource,
-			Account:  &Account{},
-			Rules: []*Rule{
-				{
-					Scope: "*",
-					Resource: &Resource{
-						Type:     webResource.Type,
-						Name:     webResource.Name,
-						Endpoint: "*",
-					},
-				},
-			},
-		},
-		{
-			Name:     "WebWildcardPathEndpointValid",
-			Resource: webResource,
-			Account:  &Account{},
-			Rules: []*Rule{
-				{
-					Scope: "*",
-					Resource: &Resource{
-						Type:     webResource.Type,
-						Name:     webResource.Name,
-						Endpoint: "/foo/*",
-					},
-				},
-			},
-		},
-		{
-			Name:     "WebWildcardPathEndpointInvalid",
-			Resource: webResource,
-			Account:  &Account{},
-			Rules: []*Rule{
-				{
-					Scope: "*",
-					Resource: &Resource{
-						Type:     webResource.Type,
-						Name:     webResource.Name,
-						Endpoint: "/bar/*",
-					},
-				},
-			},
-			Error: ErrForbidden,
-		},
-	}
-
-	for _, tc := range tt {
-		t.Run(tc.Name, func(t *testing.T) {
-			if err := VerifyAccess(tc.Rules, tc.Account, tc.Resource); err != tc.Error {
-				t.Errorf("Expected %v but got %v", tc.Error, err)
-			}
-		})
-	}
-}

broker/broker.go

@@ -1,50 +1,126 @@
 // Package broker is an interface used for asynchronous messaging
-package broker
+package broker // import "go.unistack.org/micro/v3/broker"
 
 import (
 	"context"
+	"errors"
+	"time"
 
-	"github.com/unistack-org/micro/v3/metadata"
+	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v3/metadata"
 )
 
+// DefaultBroker default memory broker
+var DefaultBroker Broker = NewBroker()
+
 var (
-	// DefaultBroker default broker
-	DefaultBroker Broker = NewBroker()
+	// ErrNotConnected returns when broker used but not connected yet
+	ErrNotConnected = errors.New("broker not connected")
+	// ErrDisconnected returns when broker disconnected
+	ErrDisconnected = errors.New("broker disconnected")
+	// DefaultGracefulTimeout
+	DefaultGracefulTimeout = 5 * time.Second
 )
 
 // Broker is an interface used for asynchronous messaging.
 type Broker interface {
+	// Name returns broker instance name
 	Name() string
-	Init(...Option) error
+	// Init initilize broker
+	Init(opts ...Option) error
+	// Options returns broker options
 	Options() Options
+	// Address return configured address
 	Address() string
-	Connect(context.Context) error
-	Disconnect(context.Context) error
-	Publish(context.Context, string, *Message, ...PublishOption) error
-	Subscribe(context.Context, string, Handler, ...SubscribeOption) (Subscriber, error)
+	// Connect connects to broker
+	Connect(ctx context.Context) error
+	// Disconnect disconnect from broker
+	Disconnect(ctx context.Context) error
+	// Publish message to broker topic
+	Publish(ctx context.Context, topic string, msg *Message, opts ...PublishOption) error
+	// Subscribe subscribes to topic message via handler
+	Subscribe(ctx context.Context, topic string, h Handler, opts ...SubscribeOption) (Subscriber, error)
+	// BatchPublish messages to broker with multiple topics
+	BatchPublish(ctx context.Context, msgs []*Message, opts ...PublishOption) error
+	// BatchSubscribe subscribes to topic messages via handler
+	BatchSubscribe(ctx context.Context, topic string, h BatchHandler, opts ...SubscribeOption) (Subscriber, error)
+	// String type of broker
 	String() string
 }
 
+type (
+	FuncPublish        func(ctx context.Context, topic string, msg *Message, opts ...PublishOption) error
+	HookPublish        func(next FuncPublish) FuncPublish
+	FuncBatchPublish   func(ctx context.Context, msgs []*Message, opts ...PublishOption) error
+	HookBatchPublish   func(next FuncBatchPublish) FuncBatchPublish
+	FuncSubscribe      func(ctx context.Context, topic string, h Handler, opts ...SubscribeOption) (Subscriber, error)
+	HookSubscribe      func(next FuncSubscribe) FuncSubscribe
+	FuncBatchSubscribe func(ctx context.Context, topic string, h BatchHandler, opts ...SubscribeOption) (Subscriber, error)
+	HookBatchSubscribe func(next FuncBatchSubscribe) FuncBatchSubscribe
+)
+
 // Handler is used to process messages via a subscription of a topic.
 type Handler func(Event) error
 
+// Events contains multiple events
+type Events []Event
+
+// Ack try to ack all events and return
+func (evs Events) Ack() error {
+	var err error
+	for _, ev := range evs {
+		if err = ev.Ack(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// SetError sets error on event
+func (evs Events) SetError(err error) {
+	for _, ev := range evs {
+		ev.SetError(err)
+	}
+}
+
+// BatchHandler is used to process messages in batches via a subscription of a topic.
+type BatchHandler func(Events) error
+
 // Event is given to a subscription handler for processing
 type Event interface {
+	// Topic returns event topic
 	Topic() string
+	// Message returns broker message
 	Message() *Message
+	// Ack acknowledge message
 	Ack() error
+	// Error returns message error (like decoding errors or some other)
 	Error() error
+	// SetError set event processing error
+	SetError(err error)
 }
 
 // Message is used to transfer data
 type Message struct {
-	Header metadata.Metadata // contains message metadata
-	Body   []byte            // contains message body
+	// Header contains message metadata
+	Header metadata.Metadata
+	// Body contains message body
+	Body codec.RawMessage
+}
+
+// NewMessage create broker message with topic filled
+func NewMessage(topic string) *Message {
+	m := &Message{Header: metadata.New(2)}
+	m.Header.Set(metadata.HeaderTopic, topic)
+	return m
 }
 
 // Subscriber is a convenience return type for the Subscribe method
 type Subscriber interface {
+	// Options returns subscriber options
 	Options() SubscribeOptions
+	// Topic returns topic for subscription
 	Topic() string
-	Unsubscribe(context.Context) error
+	// Unsubscribe from topic
+	Unsubscribe(ctx context.Context) error
 }

broker/context_test.go

@@ -0,0 +1,72 @@
+package broker
+
+import (
+	"context"
+	"testing"
+)
+
+func TestFromContext(t *testing.T) {
+	ctx := context.WithValue(context.TODO(), brokerKey{}, NewBroker())
+	c, ok := FromContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("FromContext not works")
+	}
+}
+
+func TestFromNilContext(t *testing.T) {
+	// nolint: staticcheck
+	c, ok := FromContext(nil)
+	if ok || c != nil {
+		t.Fatal("FromContext not works")
+	}
+}
+
+func TestNewContext(t *testing.T) {
+	ctx := NewContext(context.TODO(), NewBroker())
+	c, ok := FromContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("NewContext not works")
+	}
+}
+
+func TestNewNilContext(t *testing.T) {
+	// nolint: staticcheck
+	ctx := NewContext(nil, NewBroker())
+	c, ok := FromContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("NewContext not works")
+	}
+}
+
+func TestSetSubscribeOption(t *testing.T) {
+	type key struct{}
+	o := SetSubscribeOption(key{}, "test")
+	opts := &SubscribeOptions{}
+	o(opts)
+
+	if v, ok := opts.Context.Value(key{}).(string); !ok || v == "" {
+		t.Fatal("SetSubscribeOption not works")
+	}
+}
+
+func TestSetPublishOption(t *testing.T) {
+	type key struct{}
+	o := SetPublishOption(key{}, "test")
+	opts := &PublishOptions{}
+	o(opts)
+
+	if v, ok := opts.Context.Value(key{}).(string); !ok || v == "" {
+		t.Fatal("SetPublishOption not works")
+	}
+}
+
+func TestSetOption(t *testing.T) {
+	type key struct{}
+	o := SetOption(key{}, "test")
+	opts := &Options{}
+	o(opts)
+
+	if v, ok := opts.Context.Value(key{}).(string); !ok || v == "" {
+		t.Fatal("SetOption not works")
+	}
+}

broker/memory.go

@@ -1,244 +0,0 @@
-package broker
-
-import (
-	"context"
-	"errors"
-	"sync"
-
-	"github.com/google/uuid"
-	"github.com/unistack-org/micro/v3/logger"
-	maddr "github.com/unistack-org/micro/v3/util/addr"
-	mnet "github.com/unistack-org/micro/v3/util/net"
-	"github.com/unistack-org/micro/v3/util/rand"
-)
-
-type memoryBroker struct {
-	opts Options
-
-	addr string
-	sync.RWMutex
-	connected   bool
-	Subscribers map[string][]*memorySubscriber
-}
-
-type memoryEvent struct {
-	opts    Options
-	topic   string
-	err     error
-	message interface{}
-}
-
-type memorySubscriber struct {
-	id      string
-	topic   string
-	exit    chan bool
-	handler Handler
-	opts    SubscribeOptions
-	ctx     context.Context
-}
-
-func (m *memoryBroker) Options() Options {
-	return m.opts
-}
-
-func (m *memoryBroker) Address() string {
-	return m.addr
-}
-
-func (m *memoryBroker) Connect(ctx context.Context) error {
-	m.Lock()
-	defer m.Unlock()
-
-	if m.connected {
-		return nil
-	}
-
-	// use 127.0.0.1 to avoid scan of all network interfaces
-	addr, err := maddr.Extract("127.0.0.1")
-	if err != nil {
-		return err
-	}
-	var rng rand.Rand
-	i := rng.Intn(20000)
-	// set addr with port
-	addr = mnet.HostPort(addr, 10000+i)
-
-	m.addr = addr
-	m.connected = true
-
-	return nil
-}
-
-func (m *memoryBroker) Disconnect(ctx context.Context) error {
-	m.Lock()
-	defer m.Unlock()
-
-	if !m.connected {
-		return nil
-	}
-
-	m.connected = false
-
-	return nil
-}
-
-func (m *memoryBroker) Init(opts ...Option) error {
-	for _, o := range opts {
-		o(&m.opts)
-	}
-	return nil
-}
-
-func (m *memoryBroker) Publish(ctx context.Context, topic string, msg *Message, opts ...PublishOption) error {
-	m.RLock()
-	if !m.connected {
-		m.RUnlock()
-		return errors.New("not connected")
-	}
-
-	subs, ok := m.Subscribers[topic]
-	m.RUnlock()
-	if !ok {
-		return nil
-	}
-
-	var v interface{}
-	if m.opts.Codec != nil {
-		buf, err := m.opts.Codec.Marshal(msg)
-		if err != nil {
-			return err
-		}
-		v = buf
-	} else {
-		v = msg
-	}
-
-	p := &memoryEvent{
-		topic:   topic,
-		message: v,
-		opts:    m.opts,
-	}
-
-	eh := m.opts.ErrorHandler
-
-	for _, sub := range subs {
-		if err := sub.handler(p); err != nil {
-			p.err = err
-			if sub.opts.ErrorHandler != nil {
-				eh = sub.opts.ErrorHandler
-			}
-			if eh != nil {
-				eh(p)
-			} else if m.opts.Logger.V(logger.ErrorLevel) {
-				m.opts.Logger.Error(m.opts.Context, err.Error())
-			}
-			continue
-		}
-	}
-
-	return nil
-}
-
-func (m *memoryBroker) Subscribe(ctx context.Context, topic string, handler Handler, opts ...SubscribeOption) (Subscriber, error) {
-	m.RLock()
-	if !m.connected {
-		m.RUnlock()
-		return nil, errors.New("not connected")
-	}
-	m.RUnlock()
-
-	options := NewSubscribeOptions(opts...)
-
-	id, err := uuid.NewRandom()
-	if err != nil {
-		return nil, err
-	}
-
-	sub := &memorySubscriber{
-		exit:    make(chan bool, 1),
-		id:      id.String(),
-		topic:   topic,
-		handler: handler,
-		opts:    options,
-		ctx:     ctx,
-	}
-
-	m.Lock()
-	m.Subscribers[topic] = append(m.Subscribers[topic], sub)
-	m.Unlock()
-
-	go func() {
-		<-sub.exit
-		m.Lock()
-		var newSubscribers []*memorySubscriber
-		for _, sb := range m.Subscribers[topic] {
-			if sb.id == sub.id {
-				continue
-			}
-			newSubscribers = append(newSubscribers, sb)
-		}
-		m.Subscribers[topic] = newSubscribers
-		m.Unlock()
-	}()
-
-	return sub, nil
-}
-
-func (m *memoryBroker) String() string {
-	return "memory"
-}
-
-func (m *memoryBroker) Name() string {
-	return m.opts.Name
-}
-
-func (m *memoryEvent) Topic() string {
-	return m.topic
-}
-
-func (m *memoryEvent) Message() *Message {
-	switch v := m.message.(type) {
-	case *Message:
-		return v
-	case []byte:
-		msg := &Message{}
-		if err := m.opts.Codec.Unmarshal(v, msg); err != nil {
-			if m.opts.Logger.V(logger.ErrorLevel) {
-				m.opts.Logger.Error(m.opts.Context, "[memory]: failed to unmarshal: %v", err)
-			}
-			return nil
-		}
-		return msg
-	}
-
-	return nil
-}
-
-func (m *memoryEvent) Ack() error {
-	return nil
-}
-
-func (m *memoryEvent) Error() error {
-	return m.err
-}
-
-func (m *memorySubscriber) Options() SubscribeOptions {
-	return m.opts
-}
-
-func (m *memorySubscriber) Topic() string {
-	return m.topic
-}
-
-func (m *memorySubscriber) Unsubscribe(ctx context.Context) error {
-	m.exit <- true
-	return nil
-}
-
-// NewBroker return new memory broker
-func NewBroker(opts ...Option) Broker {
-	return &memoryBroker{
-		opts:        NewOptions(opts...),
-		Subscribers: make(map[string][]*memorySubscriber),
-	}
-}

broker/memory/memory.go

@@ -0,0 +1,395 @@
+package broker
+
+import (
+	"context"
+	"sync"
+
+	"go.unistack.org/micro/v3/broker"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v3/options"
+	maddr "go.unistack.org/micro/v3/util/addr"
+	"go.unistack.org/micro/v3/util/id"
+	mnet "go.unistack.org/micro/v3/util/net"
+	"go.unistack.org/micro/v3/util/rand"
+)
+
+type memoryBroker struct {
+	funcPublish        broker.FuncPublish
+	funcBatchPublish   broker.FuncBatchPublish
+	funcSubscribe      broker.FuncSubscribe
+	funcBatchSubscribe broker.FuncBatchSubscribe
+	subscribers        map[string][]*memorySubscriber
+	addr               string
+	opts               broker.Options
+	sync.RWMutex
+	connected bool
+}
+
+type memoryEvent struct {
+	err     error
+	message interface{}
+	topic   string
+	opts    broker.Options
+}
+
+type memorySubscriber struct {
+	ctx          context.Context
+	exit         chan bool
+	handler      broker.Handler
+	batchhandler broker.BatchHandler
+	id           string
+	topic        string
+	opts         broker.SubscribeOptions
+}
+
+func (m *memoryBroker) Options() broker.Options {
+	return m.opts
+}
+
+func (m *memoryBroker) Address() string {
+	return m.addr
+}
+
+func (m *memoryBroker) Connect(ctx context.Context) error {
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	default:
+	}
+
+	m.Lock()
+	defer m.Unlock()
+
+	if m.connected {
+		return nil
+	}
+
+	// use 127.0.0.1 to avoid scan of all network interfaces
+	addr, err := maddr.Extract("127.0.0.1")
+	if err != nil {
+		return err
+	}
+	var rng rand.Rand
+	i := rng.Intn(20000)
+	// set addr with port
+	addr = mnet.HostPort(addr, 10000+i)
+
+	m.addr = addr
+	m.connected = true
+
+	return nil
+}
+
+func (m *memoryBroker) Disconnect(ctx context.Context) error {
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	default:
+	}
+
+	m.Lock()
+	defer m.Unlock()
+
+	if !m.connected {
+		return nil
+	}
+
+	m.connected = false
+	return nil
+}
+
+func (m *memoryBroker) Init(opts ...broker.Option) error {
+	for _, o := range opts {
+		o(&m.opts)
+	}
+
+	m.funcPublish = m.fnPublish
+	m.funcBatchPublish = m.fnBatchPublish
+	m.funcSubscribe = m.fnSubscribe
+	m.funcBatchSubscribe = m.fnBatchSubscribe
+
+	m.opts.Hooks.EachNext(func(hook options.Hook) {
+		switch h := hook.(type) {
+		case broker.HookPublish:
+			m.funcPublish = h(m.funcPublish)
+		case broker.HookBatchPublish:
+			m.funcBatchPublish = h(m.funcBatchPublish)
+		case broker.HookSubscribe:
+			m.funcSubscribe = h(m.funcSubscribe)
+		case broker.HookBatchSubscribe:
+			m.funcBatchSubscribe = h(m.funcBatchSubscribe)
+		}
+	})
+
+	return nil
+}
+
+func (m *memoryBroker) Publish(ctx context.Context, topic string, msg *broker.Message, opts ...broker.PublishOption) error {
+	return m.funcPublish(ctx, topic, msg, opts...)
+}
+
+func (m *memoryBroker) fnPublish(ctx context.Context, topic string, msg *broker.Message, opts ...broker.PublishOption) error {
+	msg.Header.Set(metadata.HeaderTopic, topic)
+	return m.publish(ctx, []*broker.Message{msg}, opts...)
+}
+
+func (m *memoryBroker) BatchPublish(ctx context.Context, msgs []*broker.Message, opts ...broker.PublishOption) error {
+	return m.funcBatchPublish(ctx, msgs, opts...)
+}
+
+func (m *memoryBroker) fnBatchPublish(ctx context.Context, msgs []*broker.Message, opts ...broker.PublishOption) error {
+	return m.publish(ctx, msgs, opts...)
+}
+
+func (m *memoryBroker) publish(ctx context.Context, msgs []*broker.Message, opts ...broker.PublishOption) error {
+	m.RLock()
+	if !m.connected {
+		m.RUnlock()
+		return broker.ErrNotConnected
+	}
+	m.RUnlock()
+
+	var err error
+
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	default:
+		options := broker.NewPublishOptions(opts...)
+
+		msgTopicMap := make(map[string]broker.Events)
+		for _, v := range msgs {
+			p := &memoryEvent{opts: m.opts}
+
+			if m.opts.Codec == nil || options.BodyOnly {
+				p.topic, _ = v.Header.Get(metadata.HeaderTopic)
+				p.message = v.Body
+			} else {
+				p.topic, _ = v.Header.Get(metadata.HeaderTopic)
+				p.message, err = m.opts.Codec.Marshal(v)
+				if err != nil {
+					return err
+				}
+			}
+			msgTopicMap[p.topic] = append(msgTopicMap[p.topic], p)
+		}
+
+		beh := m.opts.BatchErrorHandler
+		eh := m.opts.ErrorHandler
+
+		for t, ms := range msgTopicMap {
+			m.RLock()
+			subs, ok := m.subscribers[t]
+			m.RUnlock()
+			if !ok {
+				continue
+			}
+
+			for _, sub := range subs {
+				if sub.opts.BatchErrorHandler != nil {
+					beh = sub.opts.BatchErrorHandler
+				}
+				if sub.opts.ErrorHandler != nil {
+					eh = sub.opts.ErrorHandler
+				}
+
+				switch {
+				// batch processing
+				case sub.batchhandler != nil:
+					if err = sub.batchhandler(ms); err != nil {
+						ms.SetError(err)
+						if beh != nil {
+							_ = beh(ms)
+						} else if m.opts.Logger.V(logger.ErrorLevel) {
+							m.opts.Logger.Error(m.opts.Context, err.Error())
+						}
+					} else if sub.opts.AutoAck {
+						if err = ms.Ack(); err != nil {
+							m.opts.Logger.Errorf(m.opts.Context, "ack failed: %v", err)
+						}
+					}
+					// single processing
+				case sub.handler != nil:
+					for _, p := range ms {
+						if err = sub.handler(p); err != nil {
+							p.SetError(err)
+							if eh != nil {
+								_ = eh(p)
+							} else if m.opts.Logger.V(logger.ErrorLevel) {
+								m.opts.Logger.Error(m.opts.Context, err.Error())
+							}
+						} else if sub.opts.AutoAck {
+							if err = p.Ack(); err != nil {
+								m.opts.Logger.Errorf(m.opts.Context, "ack failed: %v", err)
+							}
+						}
+					}
+				}
+			}
+		}
+	}
+
+	return nil
+}
+
+func (m *memoryBroker) BatchSubscribe(ctx context.Context, topic string, handler broker.BatchHandler, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
+	return m.funcBatchSubscribe(ctx, topic, handler, opts...)
+}
+
+func (m *memoryBroker) fnBatchSubscribe(ctx context.Context, topic string, handler broker.BatchHandler, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
+	m.RLock()
+	if !m.connected {
+		m.RUnlock()
+		return nil, broker.ErrNotConnected
+	}
+	m.RUnlock()
+
+	sid, err := id.New()
+	if err != nil {
+		return nil, err
+	}
+
+	options := broker.NewSubscribeOptions(opts...)
+
+	sub := &memorySubscriber{
+		exit:         make(chan bool, 1),
+		id:           sid,
+		topic:        topic,
+		batchhandler: handler,
+		opts:         options,
+		ctx:          ctx,
+	}
+
+	m.Lock()
+	m.subscribers[topic] = append(m.subscribers[topic], sub)
+	m.Unlock()
+
+	go func() {
+		<-sub.exit
+		m.Lock()
+		newSubscribers := make([]*memorySubscriber, 0, len(m.subscribers)-1)
+		for _, sb := range m.subscribers[topic] {
+			if sb.id == sub.id {
+				continue
+			}
+			newSubscribers = append(newSubscribers, sb)
+		}
+		m.subscribers[topic] = newSubscribers
+		m.Unlock()
+	}()
+
+	return sub, nil
+}
+
+func (m *memoryBroker) Subscribe(ctx context.Context, topic string, handler broker.Handler, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
+	return m.funcSubscribe(ctx, topic, handler, opts...)
+}
+
+func (m *memoryBroker) fnSubscribe(ctx context.Context, topic string, handler broker.Handler, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
+	m.RLock()
+	if !m.connected {
+		m.RUnlock()
+		return nil, broker.ErrNotConnected
+	}
+	m.RUnlock()
+
+	sid, err := id.New()
+	if err != nil {
+		return nil, err
+	}
+
+	options := broker.NewSubscribeOptions(opts...)
+
+	sub := &memorySubscriber{
+		exit:    make(chan bool, 1),
+		id:      sid,
+		topic:   topic,
+		handler: handler,
+		opts:    options,
+		ctx:     ctx,
+	}
+
+	m.Lock()
+	m.subscribers[topic] = append(m.subscribers[topic], sub)
+	m.Unlock()
+
+	go func() {
+		<-sub.exit
+		m.Lock()
+		newSubscribers := make([]*memorySubscriber, 0, len(m.subscribers)-1)
+		for _, sb := range m.subscribers[topic] {
+			if sb.id == sub.id {
+				continue
+			}
+			newSubscribers = append(newSubscribers, sb)
+		}
+		m.subscribers[topic] = newSubscribers
+		m.Unlock()
+	}()
+
+	return sub, nil
+}
+
+func (m *memoryBroker) String() string {
+	return "memory"
+}
+
+func (m *memoryBroker) Name() string {
+	return m.opts.Name
+}
+
+func (m *memoryEvent) Topic() string {
+	return m.topic
+}
+
+func (m *memoryEvent) Message() *broker.Message {
+	switch v := m.message.(type) {
+	case *broker.Message:
+		return v
+	case []byte:
+		msg := &broker.Message{}
+		if err := m.opts.Codec.Unmarshal(v, msg); err != nil {
+			if m.opts.Logger.V(logger.ErrorLevel) {
+				m.opts.Logger.Error(m.opts.Context, "[memory]: failed to unmarshal: %v", err)
+			}
+			return nil
+		}
+		return msg
+	}
+
+	return nil
+}
+
+func (m *memoryEvent) Ack() error {
+	return nil
+}
+
+func (m *memoryEvent) Error() error {
+	return m.err
+}
+
+func (m *memoryEvent) SetError(err error) {
+	m.err = err
+}
+
+func (m *memorySubscriber) Options() broker.SubscribeOptions {
+	return m.opts
+}
+
+func (m *memorySubscriber) Topic() string {
+	return m.topic
+}
+
+func (m *memorySubscriber) Unsubscribe(ctx context.Context) error {
+	m.exit <- true
+	return nil
+}
+
+// NewBroker return new memory broker
+func NewBroker(opts ...broker.Option) broker.Broker {
+	return &memoryBroker{
+		opts:        broker.NewOptions(opts...),
+		subscribers: make(map[string][]*memorySubscriber),
+	}
+}

broker/memory/memory_test.go

@@ -0,0 +1,114 @@
+package broker
+
+import (
+	"context"
+	"fmt"
+	"testing"
+
+	"go.unistack.org/micro/v3/broker"
+	"go.unistack.org/micro/v3/metadata"
+)
+
+func TestMemoryBatchBroker(t *testing.T) {
+	b := NewBroker()
+	ctx := context.Background()
+
+	if err := b.Init(); err != nil {
+		t.Fatalf("Unexpected init error %v", err)
+	}
+
+	if err := b.Connect(ctx); err != nil {
+		t.Fatalf("Unexpected connect error %v", err)
+	}
+
+	topic := "test"
+	count := 10
+
+	fn := func(evts broker.Events) error {
+		return evts.Ack()
+	}
+
+	sub, err := b.BatchSubscribe(ctx, topic, fn)
+	if err != nil {
+		t.Fatalf("Unexpected error subscribing %v", err)
+	}
+
+	msgs := make([]*broker.Message, 0, count)
+	for i := 0; i < count; i++ {
+		message := &broker.Message{
+			Header: map[string]string{
+				metadata.HeaderTopic: topic,
+				"foo":                "bar",
+				"id":                 fmt.Sprintf("%d", i),
+			},
+			Body: []byte(`"hello world"`),
+		}
+		msgs = append(msgs, message)
+	}
+
+	if err := b.BatchPublish(ctx, msgs); err != nil {
+		t.Fatalf("Unexpected error publishing %v", err)
+	}
+
+	if err := sub.Unsubscribe(ctx); err != nil {
+		t.Fatalf("Unexpected error unsubscribing from %s: %v", topic, err)
+	}
+
+	if err := b.Disconnect(ctx); err != nil {
+		t.Fatalf("Unexpected connect error %v", err)
+	}
+}
+
+func TestMemoryBroker(t *testing.T) {
+	b := NewBroker()
+	ctx := context.Background()
+
+	if err := b.Init(); err != nil {
+		t.Fatalf("Unexpected init error %v", err)
+	}
+
+	if err := b.Connect(ctx); err != nil {
+		t.Fatalf("Unexpected connect error %v", err)
+	}
+
+	topic := "test"
+	count := 10
+
+	fn := func(p broker.Event) error {
+		return nil
+	}
+
+	sub, err := b.Subscribe(ctx, topic, fn)
+	if err != nil {
+		t.Fatalf("Unexpected error subscribing %v", err)
+	}
+
+	msgs := make([]*broker.Message, 0, count)
+	for i := 0; i < count; i++ {
+		message := &broker.Message{
+			Header: map[string]string{
+				metadata.HeaderTopic: topic,
+				"foo":                "bar",
+				"id":                 fmt.Sprintf("%d", i),
+			},
+			Body: []byte(`"hello world"`),
+		}
+		msgs = append(msgs, message)
+
+		if err := b.Publish(ctx, topic, message); err != nil {
+			t.Fatalf("Unexpected error publishing %d err: %v", i, err)
+		}
+	}
+
+	if err := b.BatchPublish(ctx, msgs); err != nil {
+		t.Fatalf("Unexpected error publishing %v", err)
+	}
+
+	if err := sub.Unsubscribe(ctx); err != nil {
+		t.Fatalf("Unexpected error unsubscribing from %s: %v", topic, err)
+	}
+
+	if err := b.Disconnect(ctx); err != nil {
+		t.Fatalf("Unexpected connect error %v", err)
+	}
+}

broker/memory_test.go

@@ -1,50 +0,0 @@
-package broker
-
-import (
-	"context"
-	"fmt"
-	"testing"
-)
-
-func TestMemoryBroker(t *testing.T) {
-	b := NewBroker()
-	ctx := context.Background()
-
-	if err := b.Connect(ctx); err != nil {
-		t.Fatalf("Unexpected connect error %v", err)
-	}
-
-	topic := "test"
-	count := 10
-
-	fn := func(p Event) error {
-		return nil
-	}
-
-	sub, err := b.Subscribe(ctx, topic, fn)
-	if err != nil {
-		t.Fatalf("Unexpected error subscribing %v", err)
-	}
-
-	for i := 0; i < count; i++ {
-		message := &Message{
-			Header: map[string]string{
-				"foo": "bar",
-				"id":  fmt.Sprintf("%d", i),
-			},
-			Body: []byte(`hello world`),
-		}
-
-		if err := b.Publish(ctx, topic, message); err != nil {
-			t.Fatalf("Unexpected error publishing %d", i)
-		}
-	}
-
-	if err := sub.Unsubscribe(ctx); err != nil {
-		t.Fatalf("Unexpected error unsubscribing from %s: %v", topic, err)
-	}
-
-	if err := b.Disconnect(ctx); err != nil {
-		t.Fatalf("Unexpected connect error %v", err)
-	}
-}

broker/noop.go

@@ -0,0 +1,128 @@
+package broker
+
+import (
+	"context"
+	"strings"
+
+	"go.unistack.org/micro/v3/options"
+)
+
+type NoopBroker struct {
+	funcPublish        FuncPublish
+	funcBatchPublish   FuncBatchPublish
+	funcSubscribe      FuncSubscribe
+	funcBatchSubscribe FuncBatchSubscribe
+	opts               Options
+}
+
+func NewBroker(opts ...Option) *NoopBroker {
+	b := &NoopBroker{opts: NewOptions(opts...)}
+	b.funcPublish = b.fnPublish
+	b.funcBatchPublish = b.fnBatchPublish
+	b.funcSubscribe = b.fnSubscribe
+	b.funcBatchSubscribe = b.fnBatchSubscribe
+
+	return b
+}
+
+func (b *NoopBroker) Name() string {
+	return b.opts.Name
+}
+
+func (b *NoopBroker) String() string {
+	return "noop"
+}
+
+func (b *NoopBroker) Options() Options {
+	return b.opts
+}
+
+func (b *NoopBroker) Init(opts ...Option) error {
+	for _, opt := range opts {
+		opt(&b.opts)
+	}
+
+	b.funcPublish = b.fnPublish
+	b.funcBatchPublish = b.fnBatchPublish
+	b.funcSubscribe = b.fnSubscribe
+	b.funcBatchSubscribe = b.fnBatchSubscribe
+
+	b.opts.Hooks.EachNext(func(hook options.Hook) {
+		switch h := hook.(type) {
+		case HookPublish:
+			b.funcPublish = h(b.funcPublish)
+		case HookBatchPublish:
+			b.funcBatchPublish = h(b.funcBatchPublish)
+		case HookSubscribe:
+			b.funcSubscribe = h(b.funcSubscribe)
+		case HookBatchSubscribe:
+			b.funcBatchSubscribe = h(b.funcBatchSubscribe)
+		}
+	})
+
+	return nil
+}
+
+func (b *NoopBroker) Connect(_ context.Context) error {
+	return nil
+}
+
+func (b *NoopBroker) Disconnect(_ context.Context) error {
+	return nil
+}
+
+func (b *NoopBroker) Address() string {
+	return strings.Join(b.opts.Addrs, ",")
+}
+
+func (b *NoopBroker) fnBatchPublish(_ context.Context, _ []*Message, _ ...PublishOption) error {
+	return nil
+}
+
+func (b *NoopBroker) BatchPublish(ctx context.Context, msgs []*Message, opts ...PublishOption) error {
+	return b.funcBatchPublish(ctx, msgs, opts...)
+}
+
+func (b *NoopBroker) fnPublish(_ context.Context, _ string, _ *Message, _ ...PublishOption) error {
+	return nil
+}
+
+func (b *NoopBroker) Publish(ctx context.Context, topic string, msg *Message, opts ...PublishOption) error {
+	return b.funcPublish(ctx, topic, msg, opts...)
+}
+
+type NoopSubscriber struct {
+	ctx          context.Context
+	topic        string
+	handler      Handler
+	batchHandler BatchHandler
+	opts         SubscribeOptions
+}
+
+func (b *NoopBroker) fnBatchSubscribe(ctx context.Context, topic string, handler BatchHandler, opts ...SubscribeOption) (Subscriber, error) {
+	return &NoopSubscriber{ctx: ctx, topic: topic, opts: NewSubscribeOptions(opts...), batchHandler: handler}, nil
+}
+
+func (b *NoopBroker) BatchSubscribe(ctx context.Context, topic string, handler BatchHandler, opts ...SubscribeOption) (Subscriber, error) {
+	return b.funcBatchSubscribe(ctx, topic, handler, opts...)
+}
+
+func (b *NoopBroker) fnSubscribe(ctx context.Context, topic string, handler Handler, opts ...SubscribeOption) (Subscriber, error) {
+	return &NoopSubscriber{ctx: ctx, topic: topic, opts: NewSubscribeOptions(opts...), handler: handler}, nil
+}
+
+func (b *NoopBroker) Subscribe(ctx context.Context, topic string, handler Handler, opts ...SubscribeOption) (Subscriber, error) {
+	return b.funcSubscribe(ctx, topic, handler, opts...)
+}
+
+func (s *NoopSubscriber) Options() SubscribeOptions {
+	return s.opts
+}
+
+func (s *NoopSubscriber) Topic() string {
+	return s.topic
+}
+
+func (s *NoopSubscriber) Unsubscribe(_ context.Context) error {
+	return nil
+}

broker/noop_test.go

@@ -0,0 +1,35 @@
+package broker
+
+import (
+	"context"
+	"testing"
+)
+
+type testHook struct {
+	f bool
+}
+
+func (t *testHook) Publish1(fn FuncPublish) FuncPublish {
+	return func(ctx context.Context, topic string, msg *Message, opts ...PublishOption) error {
+		t.f = true
+		return fn(ctx, topic, msg, opts...)
+	}
+}
+
+func TestNoopHook(t *testing.T) {
+	h := &testHook{}
+
+	b := NewBroker(Hooks(HookPublish(h.Publish1)))
+
+	if err := b.Init(); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := b.Publish(context.TODO(), "", nil); err != nil {
+		t.Fatal(err)
+	}
+
+	if !h.f {
+		t.Fatal("hook not works")
+	}
+}

broker/options.go

@@ -3,46 +3,60 @@ package broker
 import (
 	"context"
 	"crypto/tls"
+	"time"
 
-	"github.com/unistack-org/micro/v3/codec"
-	"github.com/unistack-org/micro/v3/logger"
-	"github.com/unistack-org/micro/v3/meter"
-	"github.com/unistack-org/micro/v3/register"
-	"github.com/unistack-org/micro/v3/tracer"
+	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v3/options"
+	"go.unistack.org/micro/v3/register"
+	"go.unistack.org/micro/v3/sync"
+	"go.unistack.org/micro/v3/tracer"
 )
 
 // Options struct
 type Options struct {
-	Name string
-	// Addrs useed by broker
-	Addrs []string
-	// ErrorHandler executed when errors occur processing messages
-	ErrorHandler Handler
-	// Codec used to marshal/unmarshal messages
-	Codec codec.Codec
-	// Logger the used logger
-	Logger logger.Logger
-	// Meter the used for metrics
-	Meter meter.Meter
-	// Tracer used for trace
+	// Tracer used for tracing
 	Tracer tracer.Tracer
-	// TLSConfig for secure communication
-	TLSConfig *tls.Config
-	// Register used for clustering
+	// Register can be used for clustering
 	Register register.Register
-	// Context is used for non default options
+	// Codec holds the codec for marshal/unmarshal
+	Codec codec.Codec
+	// Logger used for logging
+	Logger logger.Logger
+	// Meter used for metrics
+	Meter meter.Meter
+	// Context holds external options
 	Context context.Context
+	// TLSConfig holds tls.TLSConfig options
+	TLSConfig *tls.Config
+	// ErrorHandler used when broker can't unmarshal incoming message
+	ErrorHandler Handler
+	// BatchErrorHandler used when broker can't unmashal incoming messages
+	BatchErrorHandler BatchHandler
+	// Name holds the broker name
+	Name string
+	// Addrs holds the broker address
+	Addrs []string
+	// Wait waits for a collection of goroutines to finish
+	Wait *sync.WaitGroup
+	// GracefulTimeout contains time to wait to finish in flight requests
+	GracefulTimeout time.Duration
+	// Hooks can be run before broker Publish/BatchPublish and
+	// Subscribe/BatchSubscribe methods
+	Hooks options.Hooks
 }
 
 // NewOptions create new Options
 func NewOptions(opts ...Option) Options {
 	options := Options{
-		Register: register.DefaultRegister,
-		Logger:   logger.DefaultLogger,
-		Context:  context.Background(),
-		Meter:    meter.DefaultMeter,
-		Codec:    codec.DefaultCodec,
-		Tracer:   tracer.DefaultTracer,
+		Register:        register.DefaultRegister,
+		Logger:          logger.DefaultLogger,
+		Context:         context.Background(),
+		Meter:           meter.DefaultMeter,
+		Codec:           codec.DefaultCodec,
+		Tracer:          tracer.DefaultTracer,
+		GracefulTimeout: DefaultGracefulTimeout,
 	}
 	for _, o := range opts {
 		o(&options)
@@ -59,10 +73,10 @@ func Context(ctx context.Context) Option {
 
 // PublishOptions struct
 type PublishOptions struct {
-	// BodyOnly says that only body of the message must be published
-	BodyOnly bool
-	// Context for non default options
+	// Context holds external options
 	Context context.Context
+	// BodyOnly flag says the message contains raw body bytes
+	BodyOnly bool
 }
 
 // NewPublishOptions creates PublishOptions struct
@@ -70,32 +84,30 @@ func NewPublishOptions(opts ...PublishOption) PublishOptions {
 	options := PublishOptions{
 		Context: context.Background(),
 	}
-
 	for _, o := range opts {
 		o(&options)
 	}
-
 	return options
 }
 
 // SubscribeOptions struct
 type SubscribeOptions struct {
-	// AutoAck ack messages if handler returns nil err
-	AutoAck bool
-
-	// ErrorHandler executed when errors occur processing messages
-	ErrorHandler Handler
-
-	// Group for subscriber, Subscribers with the same group name
-	// will create a shared subscription where each
-	// receives a subset of messages.
-	Group string
-
-	// BodyOnly says that consumed only body of the message
-	BodyOnly bool
-
-	// Context is used for non default options
+	// Context holds external options
 	Context context.Context
+	// ErrorHandler used when broker can't unmarshal incoming message
+	ErrorHandler Handler
+	// BatchErrorHandler used when broker can't unmashal incoming messages
+	BatchErrorHandler BatchHandler
+	// Group holds consumer group
+	Group string
+	// AutoAck flag specifies auto ack of incoming message when no error happens
+	AutoAck bool
+	// BodyOnly flag specifies that message contains only body bytes without header
+	BodyOnly bool
+	// BatchSize flag specifies max batch size
+	BatchSize int
+	// BatchWait flag specifies max wait time for batch filling
+	BatchWait time.Duration
 }
 
 // Option func
@@ -118,23 +130,6 @@ func PublishContext(ctx context.Context) PublishOption {
 	}
 }
 
-// SubscribeOption func
-type SubscribeOption func(*SubscribeOptions)
-
-// NewSubscribeOptions creates new SubscribeOptions
-func NewSubscribeOptions(opts ...SubscribeOption) SubscribeOptions {
-	options := SubscribeOptions{
-		AutoAck: true,
-		Context: context.Background(),
-	}
-
-	for _, o := range opts {
-		o(&options)
-	}
-
-	return options
-}
-
 // Addrs sets the host addresses to be used by the broker
 func Addrs(addrs ...string) Option {
 	return func(o *Options) {
@@ -150,28 +145,6 @@ func Codec(c codec.Codec) Option {
 	}
 }
 
-// DisableAutoAck disables auto ack
-func DisableAutoAck() SubscribeOption {
-	return func(o *SubscribeOptions) {
-		o.AutoAck = false
-	}
-}
-
-// SubscribeAutoAck will disable auto acking of messages
-// after they have been handled.
-func SubscribeAutoAck(b bool) SubscribeOption {
-	return func(o *SubscribeOptions) {
-		o.AutoAck = b
-	}
-}
-
-// SubscribeBodyOnly consumes only body of the message
-func SubscribeBodyOnly(b bool) SubscribeOption {
-	return func(o *SubscribeOptions) {
-		o.BodyOnly = b
-	}
-}
-
 // ErrorHandler will catch all broker errors that cant be handled
 // in normal way, for example Codec errors
 func ErrorHandler(h Handler) Option {
@@ -180,6 +153,14 @@ func ErrorHandler(h Handler) Option {
 	}
 }
 
+// BatchErrorHandler will catch all broker errors that cant be handled
+// in normal way, for example Codec errors
+func BatchErrorHandler(h BatchHandler) Option {
+	return func(o *Options) {
+		o.BatchErrorHandler = h
+	}
+}
+
 // SubscribeErrorHandler will catch all broker errors that cant be handled
 // in normal way, for example Codec errors
 func SubscribeErrorHandler(h Handler) SubscribeOption {
@@ -188,6 +169,14 @@ func SubscribeErrorHandler(h Handler) SubscribeOption {
 	}
 }
 
+// SubscribeBatchErrorHandler will catch all broker errors that cant be handled
+// in normal way, for example Codec errors
+func SubscribeBatchErrorHandler(h BatchHandler) SubscribeOption {
+	return func(o *SubscribeOptions) {
+		o.BatchErrorHandler = h
+	}
+}
+
 // Queue sets the subscribers queue
 // Deprecated
 func Queue(name string) SubscribeOption {
@@ -245,9 +234,68 @@ func Name(n string) Option {
 	}
 }
 
+// Hooks sets hook runs before action
+func Hooks(h ...options.Hook) Option {
+	return func(o *Options) {
+		o.Hooks = append(o.Hooks, h...)
+	}
+}
+
 // SubscribeContext set context
 func SubscribeContext(ctx context.Context) SubscribeOption {
 	return func(o *SubscribeOptions) {
 		o.Context = ctx
 	}
 }
+
+// DisableAutoAck disables auto ack
+// Deprecated
+func DisableAutoAck() SubscribeOption {
+	return func(o *SubscribeOptions) {
+		o.AutoAck = false
+	}
+}
+
+// SubscribeAutoAck contol auto acking of messages
+// after they have been handled.
+func SubscribeAutoAck(b bool) SubscribeOption {
+	return func(o *SubscribeOptions) {
+		o.AutoAck = b
+	}
+}
+
+// SubscribeBodyOnly consumes only body of the message
+func SubscribeBodyOnly(b bool) SubscribeOption {
+	return func(o *SubscribeOptions) {
+		o.BodyOnly = b
+	}
+}
+
+// SubscribeBatchSize specifies max batch size
+func SubscribeBatchSize(n int) SubscribeOption {
+	return func(o *SubscribeOptions) {
+		o.BatchSize = n
+	}
+}
+
+// SubscribeBatchWait specifies max batch wait time
+func SubscribeBatchWait(td time.Duration) SubscribeOption {
+	return func(o *SubscribeOptions) {
+		o.BatchWait = td
+	}
+}
+
+// SubscribeOption func
+type SubscribeOption func(*SubscribeOptions)
+
+// NewSubscribeOptions creates new SubscribeOptions
+func NewSubscribeOptions(opts ...SubscribeOption) SubscribeOptions {
+	options := SubscribeOptions{
+		AutoAck: true,
+		Context: context.Background(),
+	}
+	for _, o := range opts {
+		o(&options)
+	}
+	return options
+}

build/build.go

@@ -1,32 +0,0 @@
-// Package build is for building source into a package
-package build
-
-// Build is an interface for building packages
-type Build interface {
-	// Package builds a package
-	Package(name string, src *Source) (*Package, error)
-	// Remove removes the package
-	Remove(*Package) error
-}
-
-// Source is the source of a build
-type Source struct {
-	// Path to the source if local
-	Path string
-	// Language is the language of code
-	Language string
-	// Location of the source
-	Repository string
-}
-
-// Package is packaged format for source
-type Package struct {
-	// Name of the package
-	Name string
-	// Location of the package
-	Path string
-	// Type of package e.g tarball, binary, docker
-	Type string
-	// Source of the package
-	Source *Source
-}

build/options.go

@@ -1,17 +0,0 @@
-package build
-
-// Options struct
-type Options struct {
-	// local path to download source
-	Path string
-}
-
-// Option func
-type Option func(o *Options)
-
-// Path is the Local path for repository
-func Path(p string) Option {
-	return func(o *Options) {
-		o.Path = p
-	}
-}

client/backoff.go

@@ -2,14 +2,29 @@ package client
 
 import (
 	"context"
+	"math"
 	"time"
 
-	"github.com/unistack-org/micro/v3/util/backoff"
+	"go.unistack.org/micro/v3/util/backoff"
 )
 
 // BackoffFunc is the backoff call func
 type BackoffFunc func(ctx context.Context, req Request, attempts int) (time.Duration, error)
 
-func exponentialBackoff(ctx context.Context, req Request, attempts int) (time.Duration, error) {
+// BackoffExp using exponential backoff func
+func BackoffExp(_ context.Context, _ Request, attempts int) (time.Duration, error) {
 	return backoff.Do(attempts), nil
 }
+
+// BackoffInterval specifies randomization interval for backoff func
+func BackoffInterval(min time.Duration, max time.Duration) BackoffFunc {
+	return func(_ context.Context, _ Request, attempts int) (time.Duration, error) {
+		td := time.Duration(math.Pow(float64(attempts), math.E)) * time.Millisecond * 100
+		if td < min {
+			return min, nil
+		} else if td > max {
+			return max, nil
+		}
+		return td, nil
+	}
+}

client/backoff_test.go

@@ -6,7 +6,7 @@ import (
 	"time"
 )
 
-func TestBackoff(t *testing.T) {
+func TestBackoffExp(t *testing.T) {
 	results := []time.Duration{
 		0 * time.Second,
 		100 * time.Millisecond,
@@ -22,7 +22,7 @@ func TestBackoff(t *testing.T) {
 	}
 
 	for i := 0; i < 5; i++ {
-		d, err := exponentialBackoff(context.TODO(), r, i)
+		d, err := BackoffExp(context.TODO(), r, i)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -32,3 +32,25 @@ func TestBackoff(t *testing.T) {
 		}
 	}
 }
+
+func TestBackoffInterval(t *testing.T) {
+	min := 100 * time.Millisecond
+	max := 300 * time.Millisecond
+
+	r := &testRequest{
+		service: "test",
+		method:  "test",
+	}
+
+	fn := BackoffInterval(min, max)
+	for i := 0; i < 5; i++ {
+		d, err := fn(context.TODO(), r, i)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if d < min || d > max {
+			t.Fatalf("Expected %v < %v < %v", min, d, max)
+		}
+	}
+}

client/client.go

@@ -1,21 +1,21 @@
 // Package client is an interface for an RPC client
-package client
+package client // import "go.unistack.org/micro/v3/client"
 
 import (
 	"context"
 	"time"
 
-	"github.com/unistack-org/micro/v3/codec"
-	"github.com/unistack-org/micro/v3/metadata"
+	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v3/metadata"
 )
 
 var (
 	// DefaultClient is the global default client
-	DefaultClient Client = NewClient()
+	DefaultClient = NewClient()
 	// DefaultContentType is the default content-type if not specified
-	DefaultContentType = "application/json"
-	// DefaultBackoff is the default backoff function for retries
-	DefaultBackoff = exponentialBackoff
+	DefaultContentType = ""
+	// DefaultBackoff is the default backoff function for retries (minimum 10 millisecond and maximum 5 second)
+	DefaultBackoff = BackoffInterval(10*time.Millisecond, 5*time.Second)
 	// DefaultRetry is the default check-for-retry function for retries
 	DefaultRetry = RetryNever
 	// DefaultRetries is the default number of times a request is tried
@@ -40,14 +40,27 @@ type Client interface {
 	Call(ctx context.Context, req Request, rsp interface{}, opts ...CallOption) error
 	Stream(ctx context.Context, req Request, opts ...CallOption) (Stream, error)
 	Publish(ctx context.Context, msg Message, opts ...PublishOption) error
+	BatchPublish(ctx context.Context, msg []Message, opts ...PublishOption) error
 	String() string
 }
 
+type (
+	FuncCall         func(ctx context.Context, req Request, rsp interface{}, opts ...CallOption) error
+	HookCall         func(next FuncCall) FuncCall
+	FuncStream       func(ctx context.Context, req Request, opts ...CallOption) (Stream, error)
+	HookStream       func(next FuncStream) FuncStream
+	FuncPublish      func(ctx context.Context, msg Message, opts ...PublishOption) error
+	HookPublish      func(next FuncPublish) FuncPublish
+	FuncBatchPublish func(ctx context.Context, msg []Message, opts ...PublishOption) error
+	HookBatchPublish func(next FuncBatchPublish) FuncBatchPublish
+)
+
 // Message is the interface for publishing asynchronously
 type Message interface {
 	Topic() string
 	Payload() interface{}
 	ContentType() string
+	Metadata() metadata.Metadata
 }
 
 // Request is the interface for a synchronous request used by Call or Stream
@@ -72,7 +85,7 @@ type Request interface {
 type Response interface {
 	// Read the response
 	Codec() codec.Codec
-	// read the header
+	// Header data
 	Header() metadata.Metadata
 	// Read the undecoded response
 	Read() ([]byte, error)
@@ -90,10 +103,16 @@ type Stream interface {
 	Send(msg interface{}) error
 	// Recv will decode and read a response
 	Recv(msg interface{}) error
+	// SendMsg will encode and send a request
+	SendMsg(msg interface{}) error
+	// RecvMsg will decode and read a response
+	RecvMsg(msg interface{}) error
 	// Error returns the stream error
 	Error() error
 	// Close closes the stream
 	Close() error
+	// CloseSend closes the send direction of the stream
+	CloseSend() error
 }
 
 // Option used by the Client

client/context_test.go

@@ -0,0 +1,73 @@
+package client
+
+import (
+	"context"
+	"testing"
+)
+
+func TestFromContext(t *testing.T) {
+	ctx := context.WithValue(context.TODO(), clientKey{}, NewClient())
+
+	c, ok := FromContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("FromContext not works")
+	}
+}
+
+func TestFromNilContext(t *testing.T) {
+	// nolint: staticcheck
+	c, ok := FromContext(nil)
+	if ok || c != nil {
+		t.Fatal("FromContext not works")
+	}
+}
+
+func TestNewContext(t *testing.T) {
+	ctx := NewContext(context.TODO(), NewClient())
+	c, ok := FromContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("NewContext not works")
+	}
+}
+
+func TestNewNilContext(t *testing.T) {
+	// nolint: staticcheck
+	ctx := NewContext(nil, NewClient())
+	c, ok := FromContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("NewContext not works")
+	}
+}
+
+func TestSetPublishOption(t *testing.T) {
+	type key struct{}
+	o := SetPublishOption(key{}, "test")
+	opts := &PublishOptions{}
+	o(opts)
+
+	if v, ok := opts.Context.Value(key{}).(string); !ok || v == "" {
+		t.Fatal("SetPublishOption not works")
+	}
+}
+
+func TestSetCallOption(t *testing.T) {
+	type key struct{}
+	o := SetCallOption(key{}, "test")
+	opts := &CallOptions{}
+	o(opts)
+
+	if v, ok := opts.Context.Value(key{}).(string); !ok || v == "" {
+		t.Fatal("SetCallOption not works")
+	}
+}
+
+func TestSetOption(t *testing.T) {
+	type key struct{}
+	o := SetOption(key{}, "test")
+	opts := &Options{}
+	o(opts)
+
+	if v, ok := opts.Context.Value(key{}).(string); !ok || v == "" {
+		t.Fatal("SetOption not works")
+	}
+}

client/lookup.go

@@ -4,15 +4,15 @@ import (
 	"context"
 	"sort"
 
-	"github.com/unistack-org/micro/v3/errors"
-	"github.com/unistack-org/micro/v3/router"
+	"go.unistack.org/micro/v3/errors"
+	"go.unistack.org/micro/v3/router"
 )
 
 // LookupFunc is used to lookup routes for a service
 type LookupFunc func(context.Context, Request, CallOptions) ([]string, error)
 
 // LookupRoute for a request using the router and then choose one using the selector
-func LookupRoute(ctx context.Context, req Request, opts CallOptions) ([]string, error) {
+func LookupRoute(_ context.Context, req Request, opts CallOptions) ([]string, error) {
 	// check to see if an address was provided as a call option
 	if len(opts.Address) > 0 {
 		return opts.Address, nil

client/noop.go

@@ -2,26 +2,32 @@ package client
 
 import (
 	"context"
+	"fmt"
+	"os"
+	"strconv"
+	"time"
 
-	"github.com/unistack-org/micro/v3/broker"
-	"github.com/unistack-org/micro/v3/codec"
-	"github.com/unistack-org/micro/v3/errors"
-	"github.com/unistack-org/micro/v3/metadata"
+	"go.unistack.org/micro/v3/broker"
+	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v3/errors"
+	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v3/options"
+	"go.unistack.org/micro/v3/selector"
+	"go.unistack.org/micro/v3/semconv"
+	"go.unistack.org/micro/v3/tracer"
 )
 
-var (
-	// DefaultCodecs will be used to encode/decode data
-	DefaultCodecs = map[string]codec.Codec{
-		//"application/json":         cjson.NewCodec,
-		//"application/json-rpc":     cjsonrpc.NewCodec,
-		//"application/protobuf":     cproto.NewCodec,
-		//"application/proto-rpc":    cprotorpc.NewCodec,
-		"application/octet-stream": codec.NewCodec(),
-	}
-)
+// DefaultCodecs will be used to encode/decode data
+var DefaultCodecs = map[string]codec.Codec{
+	"application/octet-stream": codec.NewCodec(),
+}
 
 type noopClient struct {
-	opts Options
+	funcPublish      FuncPublish
+	funcBatchPublish FuncBatchPublish
+	funcCall         FuncCall
+	funcStream       FuncStream
+	opts             Options
 }
 
 type noopMessage struct {
@@ -31,27 +37,25 @@ type noopMessage struct {
 }
 
 type noopRequest struct {
+	body        interface{}
+	codec       codec.Codec
 	service     string
 	method      string
 	endpoint    string
 	contentType string
-	body        interface{}
-	codec       codec.Codec
 	stream      bool
 }
 
 // NewClient returns new noop client
 func NewClient(opts ...Option) Client {
-	nc := &noopClient{opts: NewOptions(opts...)}
-	// wrap in reverse
+	n := &noopClient{opts: NewOptions(opts...)}
 
-	c := Client(nc)
+	n.funcCall = n.fnCall
+	n.funcStream = n.fnStream
+	n.funcPublish = n.fnPublish
+	n.funcBatchPublish = n.fnBatchPublish
 
-	for i := len(nc.opts.Wrappers); i > 0; i-- {
-		c = nc.opts.Wrappers[i-1](c)
-	}
-
-	return c
+	return n
 }
 
 func (n *noopClient) Name() string {
@@ -103,10 +107,13 @@ func (n *noopResponse) Read() ([]byte, error) {
 	return nil, nil
 }
 
-type noopStream struct{}
+type noopStream struct {
+	err error
+	ctx context.Context
+}
 
 func (n *noopStream) Context() context.Context {
-	return context.Background()
+	return n.ctx
 }
 
 func (n *noopStream) Request() Request {
@@ -125,14 +132,32 @@ func (n *noopStream) Recv(interface{}) error {
 	return nil
 }
 
-func (n *noopStream) Error() error {
+func (n *noopStream) SendMsg(interface{}) error {
 	return nil
 }
 
-func (n *noopStream) Close() error {
+func (n *noopStream) RecvMsg(interface{}) error {
 	return nil
 }
 
+func (n *noopStream) Error() error {
+	return n.err
+}
+
+func (n *noopStream) Close() error {
+	if sp, ok := tracer.SpanFromContext(n.ctx); ok && sp != nil {
+		if n.err != nil {
+			sp.SetStatus(tracer.SpanStatusError, n.err.Error())
+		}
+		sp.Finish()
+	}
+	return n.err
+}
+
+func (n *noopStream) CloseSend() error {
+	return n.err
+}
+
 func (n *noopMessage) Topic() string {
 	return n.topic
 }
@@ -145,6 +170,10 @@ func (n *noopMessage) ContentType() string {
 	return n.opts.ContentType
 }
 
+func (n *noopMessage) Metadata() metadata.Metadata {
+	return n.opts.Metadata
+}
+
 func (n *noopClient) newCodec(contentType string) (codec.Codec, error) {
 	if cf, ok := n.opts.Codecs[contentType]; ok {
 		return cf, nil
@@ -159,6 +188,25 @@ func (n *noopClient) Init(opts ...Option) error {
 	for _, o := range opts {
 		o(&n.opts)
 	}
+
+	n.funcCall = n.fnCall
+	n.funcStream = n.fnStream
+	n.funcPublish = n.fnPublish
+	n.funcBatchPublish = n.fnBatchPublish
+
+	n.opts.Hooks.EachNext(func(hook options.Hook) {
+		switch h := hook.(type) {
+		case HookCall:
+			n.funcCall = h(n.funcCall)
+		case HookStream:
+			n.funcStream = h(n.funcStream)
+		case HookPublish:
+			n.funcPublish = h(n.funcPublish)
+		case HookBatchPublish:
+			n.funcBatchPublish = h(n.funcBatchPublish)
+		}
+	})
+
 	return nil
 }
 
@@ -171,7 +219,157 @@ func (n *noopClient) String() string {
 }
 
 func (n *noopClient) Call(ctx context.Context, req Request, rsp interface{}, opts ...CallOption) error {
-	return nil
+	ts := time.Now()
+	n.opts.Meter.Counter(semconv.ClientRequestInflight, "endpoint", req.Endpoint()).Inc()
+	var sp tracer.Span
+	ctx, sp = n.opts.Tracer.Start(ctx, req.Endpoint()+" rpc-client",
+		tracer.WithSpanKind(tracer.SpanKindClient),
+		tracer.WithSpanLabels("endpoint", req.Endpoint()),
+	)
+	err := n.funcCall(ctx, req, rsp, opts...)
+	n.opts.Meter.Counter(semconv.ClientRequestInflight, "endpoint", req.Endpoint()).Dec()
+	te := time.Since(ts)
+	n.opts.Meter.Summary(semconv.ClientRequestLatencyMicroseconds, "endpoint", req.Endpoint()).Update(te.Seconds())
+	n.opts.Meter.Histogram(semconv.ClientRequestDurationSeconds, "endpoint", req.Endpoint()).Update(te.Seconds())
+
+	if me := errors.FromError(err); me == nil {
+		sp.Finish()
+		n.opts.Meter.Counter(semconv.ClientRequestTotal, "endpoint", req.Endpoint(), "status", "success", "code", strconv.Itoa(int(200))).Inc()
+	} else {
+		sp.SetStatus(tracer.SpanStatusError, err.Error())
+		n.opts.Meter.Counter(semconv.ClientRequestTotal, "endpoint", req.Endpoint(), "status", "failure", "code", strconv.Itoa(int(me.Code))).Inc()
+	}
+
+	return err
+}
+
+func (n *noopClient) fnCall(ctx context.Context, req Request, rsp interface{}, opts ...CallOption) error {
+	// make a copy of call opts
+	callOpts := n.opts.CallOptions
+	for _, opt := range opts {
+		opt(&callOpts)
+	}
+
+	// check if we already have a deadline
+	d, ok := ctx.Deadline()
+	if !ok {
+		var cancel context.CancelFunc
+		// no deadline so we create a new one
+		ctx, cancel = context.WithTimeout(ctx, callOpts.RequestTimeout)
+		defer cancel()
+	} else {
+		// got a deadline so no need to setup context
+		// but we need to set the timeout we pass along
+		opt := WithRequestTimeout(time.Until(d))
+		opt(&callOpts)
+	}
+
+	// should we noop right here?
+	select {
+	case <-ctx.Done():
+		return errors.New("go.micro.client", fmt.Sprintf("%v", ctx.Err()), 408)
+	default:
+	}
+
+	// make copy of call method
+	hcall := func(ctx context.Context, addr string, req Request, rsp interface{}, opts CallOptions) error {
+		return nil
+	}
+
+	// use the router passed as a call option, or fallback to the rpc clients router
+	if callOpts.Router == nil {
+		callOpts.Router = n.opts.Router
+	}
+
+	if callOpts.Selector == nil {
+		callOpts.Selector = n.opts.Selector
+	}
+
+	// inject proxy address
+	// TODO: don't even bother using Lookup/Select in this case
+	if len(n.opts.Proxy) > 0 {
+		callOpts.Address = []string{n.opts.Proxy}
+	}
+
+	var next selector.Next
+
+	// return errors.New("go.micro.client", "request timeout", 408)
+	call := func(i int) error {
+		// call backoff first. Someone may want an initial start delay
+		t, err := callOpts.Backoff(ctx, req, i)
+		if err != nil {
+			return errors.InternalServerError("go.micro.client", err.Error())
+		}
+
+		// only sleep if greater than 0
+		if t.Seconds() > 0 {
+			time.Sleep(t)
+		}
+
+		if next == nil {
+			var routes []string
+			// lookup the route to send the reques to
+			// TODO apply any filtering here
+			routes, err = n.opts.Lookup(ctx, req, callOpts)
+			if err != nil {
+				return errors.InternalServerError("go.micro.client", err.Error())
+			}
+
+			// balance the list of nodes
+			next, err = callOpts.Selector.Select(routes)
+			if err != nil {
+				return err
+			}
+		}
+
+		node := next()
+
+		// make the call
+		err = hcall(ctx, node, req, rsp, callOpts)
+		// record the result of the call to inform future routing decisions
+		if verr := n.opts.Selector.Record(node, err); verr != nil {
+			return verr
+		}
+
+		// try and transform the error to a go-micro error
+		if verr, ok := err.(*errors.Error); ok {
+			return verr
+		}
+
+		return err
+	}
+
+	ch := make(chan error, callOpts.Retries)
+	var gerr error
+
+	for i := 0; i <= callOpts.Retries; i++ {
+		go func() {
+			ch <- call(i)
+		}()
+
+		select {
+		case <-ctx.Done():
+			return errors.New("go.micro.client", fmt.Sprintf("%v", ctx.Err()), 408)
+		case err := <-ch:
+			// if the call succeeded lets bail early
+			if err == nil {
+				return nil
+			}
+
+			retry, rerr := callOpts.Retry(ctx, req, i, err)
+			if rerr != nil {
+				return rerr
+			}
+
+			if !retry {
+				return err
+			}
+
+			gerr = err
+		}
+	}
+
+	return gerr
 }
 
 func (n *noopClient) NewRequest(service, endpoint string, req interface{}, opts ...RequestOption) Request {
@@ -179,53 +377,261 @@ func (n *noopClient) NewRequest(service, endpoint string, req interface{}, opts
 }
 
 func (n *noopClient) NewMessage(topic string, msg interface{}, opts ...MessageOption) Message {
-	options := NewMessageOptions(opts...)
+	options := NewMessageOptions(append([]MessageOption{MessageContentType(n.opts.ContentType)}, opts...)...)
 	return &noopMessage{topic: topic, payload: msg, opts: options}
 }
 
 func (n *noopClient) Stream(ctx context.Context, req Request, opts ...CallOption) (Stream, error) {
-	return &noopStream{}, nil
+	ts := time.Now()
+	n.opts.Meter.Counter(semconv.ClientRequestInflight, "endpoint", req.Endpoint()).Inc()
+	var sp tracer.Span
+	ctx, sp = n.opts.Tracer.Start(ctx, req.Endpoint()+" rpc-client",
+		tracer.WithSpanKind(tracer.SpanKindClient),
+		tracer.WithSpanLabels("endpoint", req.Endpoint()),
+	)
+	stream, err := n.funcStream(ctx, req, opts...)
+	n.opts.Meter.Counter(semconv.ClientRequestInflight, "endpoint", req.Endpoint()).Dec()
+	te := time.Since(ts)
+	n.opts.Meter.Summary(semconv.ClientRequestLatencyMicroseconds, "endpoint", req.Endpoint()).Update(te.Seconds())
+	n.opts.Meter.Histogram(semconv.ClientRequestDurationSeconds, "endpoint", req.Endpoint()).Update(te.Seconds())
+
+	if me := errors.FromError(err); me == nil {
+		sp.Finish()
+		n.opts.Meter.Counter(semconv.ClientRequestTotal, "endpoint", req.Endpoint(), "status", "success", "code", strconv.Itoa(int(200))).Inc()
+	} else {
+		sp.SetStatus(tracer.SpanStatusError, err.Error())
+		n.opts.Meter.Counter(semconv.ClientRequestTotal, "endpoint", req.Endpoint(), "status", "failure", "code", strconv.Itoa(int(me.Code))).Inc()
+	}
+
+	return stream, err
+}
+
+func (n *noopClient) fnStream(ctx context.Context, req Request, opts ...CallOption) (Stream, error) {
+	var err error
+
+	// make a copy of call opts
+	callOpts := n.opts.CallOptions
+	for _, o := range opts {
+		o(&callOpts)
+	}
+
+	// check if we already have a deadline
+	d, ok := ctx.Deadline()
+	if !ok && callOpts.StreamTimeout > time.Duration(0) {
+		var cancel context.CancelFunc
+		// no deadline so we create a new one
+		ctx, cancel = context.WithTimeout(ctx, callOpts.StreamTimeout)
+		defer cancel()
+	} else {
+		// got a deadline so no need to setup context
+		// but we need to set the timeout we pass along
+		o := WithStreamTimeout(time.Until(d))
+		o(&callOpts)
+	}
+
+	// should we noop right here?
+	select {
+	case <-ctx.Done():
+		return nil, errors.New("go.micro.client", fmt.Sprintf("%v", ctx.Err()), 408)
+	default:
+	}
+
+	/*
+		// make copy of call method
+		hstream := h.stream
+		// wrap the call in reverse
+		for i := len(callOpts.CallWrappers); i > 0; i-- {
+			hstream = callOpts.CallWrappers[i-1](hstream)
+		}
+	*/
+
+	// use the router passed as a call option, or fallback to the rpc clients router
+	if callOpts.Router == nil {
+		callOpts.Router = n.opts.Router
+	}
+
+	if callOpts.Selector == nil {
+		callOpts.Selector = n.opts.Selector
+	}
+
+	// inject proxy address
+	// TODO: don't even bother using Lookup/Select in this case
+	if len(n.opts.Proxy) > 0 {
+		callOpts.Address = []string{n.opts.Proxy}
+	}
+
+	var next selector.Next
+
+	call := func(i int) (Stream, error) {
+		// call backoff first. Someone may want an initial start delay
+		t, cerr := callOpts.Backoff(ctx, req, i)
+		if cerr != nil {
+			return nil, errors.InternalServerError("go.micro.client", cerr.Error())
+		}
+
+		// only sleep if greater than 0
+		if t.Seconds() > 0 {
+			time.Sleep(t)
+		}
+
+		if next == nil {
+			var routes []string
+			// lookup the route to send the reques to
+			// TODO apply any filtering here
+			routes, err = n.opts.Lookup(ctx, req, callOpts)
+			if err != nil {
+				return nil, errors.InternalServerError("go.micro.client", err.Error())
+			}
+
+			// balance the list of nodes
+			next, err = callOpts.Selector.Select(routes)
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		node := next()
+
+		stream, cerr := n.stream(ctx, node, req, callOpts)
+
+		// record the result of the call to inform future routing decisions
+		if verr := n.opts.Selector.Record(node, cerr); verr != nil {
+			return nil, verr
+		}
+
+		// try and transform the error to a go-micro error
+		if verr, ok := cerr.(*errors.Error); ok {
+			return nil, verr
+		}
+
+		return stream, cerr
+	}
+
+	type response struct {
+		stream Stream
+		err    error
+	}
+
+	ch := make(chan response, callOpts.Retries)
+	var grr error
+
+	for i := 0; i <= callOpts.Retries; i++ {
+		go func() {
+			s, cerr := call(i)
+			ch <- response{s, cerr}
+		}()
+
+		select {
+		case <-ctx.Done():
+			return nil, errors.New("go.micro.client", fmt.Sprintf("%v", ctx.Err()), 408)
+		case rsp := <-ch:
+			// if the call succeeded lets bail early
+			if rsp.err == nil {
+				return rsp.stream, nil
+			}
+
+			retry, rerr := callOpts.Retry(ctx, req, i, err)
+			if rerr != nil {
+				return nil, rerr
+			}
+
+			if !retry {
+				return nil, rsp.err
+			}
+
+			grr = rsp.err
+		}
+	}
+
+	return nil, grr
+}
+
+func (n *noopClient) stream(ctx context.Context, addr string, req Request, opts CallOptions) (Stream, error) {
+	return &noopStream{ctx: ctx}, nil
+}
+
+func (n *noopClient) BatchPublish(ctx context.Context, ps []Message, opts ...PublishOption) error {
+	return n.funcBatchPublish(ctx, ps, opts...)
+}
+
+func (n *noopClient) fnBatchPublish(ctx context.Context, ps []Message, opts ...PublishOption) error {
+	return n.publish(ctx, ps, opts...)
 }
 
 func (n *noopClient) Publish(ctx context.Context, p Message, opts ...PublishOption) error {
-	var body []byte
+	return n.funcPublish(ctx, p, opts...)
+}
 
+func (n *noopClient) fnPublish(ctx context.Context, p Message, opts ...PublishOption) error {
+	return n.publish(ctx, []Message{p}, opts...)
+}
+
+func (n *noopClient) publish(ctx context.Context, ps []Message, opts ...PublishOption) error {
 	options := NewPublishOptions(opts...)
 
-	md, ok := metadata.FromOutgoingContext(ctx)
-	if !ok {
-		md = metadata.New(0)
+	msgs := make([]*broker.Message, 0, len(ps))
+
+	// get proxy
+	exchange := ""
+	if v, ok := os.LookupEnv("MICRO_PROXY"); ok {
+		exchange = v
 	}
-	md["Content-Type"] = p.ContentType()
-	md["Micro-Topic"] = p.Topic()
-
-	// passed in raw data
-	if d, ok := p.Payload().(*codec.Frame); ok {
-		body = d.Data
-	} else {
-		// use codec for payload
-		cf, err := n.newCodec(p.ContentType())
-		if err != nil {
-			return errors.InternalServerError("go.micro.client", err.Error())
-		}
-
-		// set the body
-		b, err := cf.Marshal(p.Payload())
-		if err != nil {
-			return errors.InternalServerError("go.micro.client", err.Error())
-		}
-		body = b
-	}
-
-	topic := p.Topic()
-
 	// get the exchange
 	if len(options.Exchange) > 0 {
-		topic = options.Exchange
+		exchange = options.Exchange
 	}
 
-	return n.opts.Broker.Publish(ctx, topic, &broker.Message{
-		Header: md,
-		Body:   body,
-	}, broker.PublishContext(options.Context))
+	omd, ok := metadata.FromOutgoingContext(ctx)
+	if !ok {
+		omd = metadata.New(0)
+	}
+
+	for _, p := range ps {
+		md := metadata.Copy(omd)
+		md[metadata.HeaderContentType] = p.ContentType()
+		topic := p.Topic()
+		if len(exchange) > 0 {
+			topic = exchange
+		}
+		md[metadata.HeaderTopic] = topic
+		iter := p.Metadata().Iterator()
+		var k, v string
+		for iter.Next(&k, &v) {
+			md.Set(k, v)
+		}
+
+		var body []byte
+
+		// passed in raw data
+		if d, ok := p.Payload().(*codec.Frame); ok {
+			body = d.Data
+		} else {
+			// use codec for payload
+			cf, err := n.newCodec(p.ContentType())
+			if err != nil {
+				return errors.InternalServerError("go.micro.client", err.Error())
+			}
+
+			// set the body
+			b, err := cf.Marshal(p.Payload())
+			if err != nil {
+				return errors.InternalServerError("go.micro.client", err.Error())
+			}
+			body = b
+		}
+
+		msgs = append(msgs, &broker.Message{Header: md, Body: body})
+	}
+
+	if len(msgs) == 1 {
+		return n.opts.Broker.Publish(ctx, msgs[0].Header[metadata.HeaderTopic], msgs[0],
+			broker.PublishContext(options.Context),
+			broker.PublishBodyOnly(options.BodyOnly),
+		)
+	}
+
+	return n.opts.Broker.BatchPublish(ctx, msgs,
+		broker.PublishContext(options.Context),
+		broker.PublishBodyOnly(options.BodyOnly),
+	)
 }

client/noop_test.go

@@ -0,0 +1,35 @@
+package client
+
+import (
+	"context"
+	"testing"
+)
+
+type testHook struct {
+	f bool
+}
+
+func (t *testHook) Publish(fn FuncPublish) FuncPublish {
+	return func(ctx context.Context, msg Message, opts ...PublishOption) error {
+		t.f = true
+		return fn(ctx, msg, opts...)
+	}
+}
+
+func TestNoopHook(t *testing.T) {
+	h := &testHook{}
+
+	c := NewClient(Hooks(HookPublish(h.Publish)))
+
+	if err := c.Init(); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := c.Publish(context.TODO(), c.NewMessage("", nil, MessageContentType("application/octet-stream"))); err != nil {
+		t.Fatal(err)
+	}
+
+	if !h.f {
+		t.Fatal("hook not works")
+	}
+}

client/options.go

@@ -2,51 +2,67 @@ package client
 
 import (
 	"context"
+	"crypto/tls"
+	"net"
 	"time"
 
-	"github.com/unistack-org/micro/v3/broker"
-	"github.com/unistack-org/micro/v3/codec"
-	"github.com/unistack-org/micro/v3/logger"
-	"github.com/unistack-org/micro/v3/meter"
-	"github.com/unistack-org/micro/v3/network/transport"
-	"github.com/unistack-org/micro/v3/register"
-	"github.com/unistack-org/micro/v3/router"
-	"github.com/unistack-org/micro/v3/selector"
-	"github.com/unistack-org/micro/v3/selector/random"
-	"github.com/unistack-org/micro/v3/tracer"
+	"go.unistack.org/micro/v3/broker"
+	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v3/network/transport"
+	"go.unistack.org/micro/v3/options"
+	"go.unistack.org/micro/v3/register"
+	"go.unistack.org/micro/v3/router"
+	"go.unistack.org/micro/v3/selector"
+	"go.unistack.org/micro/v3/selector/random"
+	"go.unistack.org/micro/v3/tracer"
 )
 
 // Options holds client options
 type Options struct {
-	Name string
-	// Used to select codec
-	ContentType string
-	// Proxy address to send requests via
-	Proxy string
-
-	// Plugged interfaces
-	Broker    broker.Broker
-	Codecs    map[string]codec.Codec
-	Router    router.Router
-	Selector  selector.Selector
+	// Transport used for transfer messages
 	Transport transport.Transport
-	Logger    logger.Logger
-	Meter     meter.Meter
-	// Lookup used for looking up routes
-	Lookup LookupFunc
-
-	// Connection Pool
-	PoolSize int
-	PoolTTL  time.Duration
-	Tracer   tracer.Tracer
-	// Wrapper that used client
-	Wrappers []Wrapper
-
-	// CallOptions that used by default
-	CallOptions CallOptions
-
-	// Context is used for non default options
+	// Selector used to select needed address
+	Selector selector.Selector
+	// Logger used to log messages
+	Logger logger.Logger
+	// Tracer used for tracing
+	Tracer tracer.Tracer
+	// Broker used to publish messages
+	Broker broker.Broker
+	// Meter used for metrics
+	Meter meter.Meter
+	// Context is used for external options
 	Context context.Context
+	// Router used to get route
+	Router router.Router
+	// TLSConfig specifies tls.Config for secure connection
+	TLSConfig *tls.Config
+	// Codecs map
+	Codecs map[string]codec.Codec
+	// Lookup func used to get destination addr
+	Lookup LookupFunc
+	// Proxy is used for proxy requests
+	Proxy string
+	// ContentType is used to select codec
+	ContentType string
+	// Name is the client name
+	Name string
+	// Wrappers contains wrappers
+	Wrappers []Wrapper
+	// CallOptions contains default CallOptions
+	CallOptions CallOptions
+	// PoolSize connection pool size
+	PoolSize int
+	// PoolTTL connection pool ttl
+	PoolTTL time.Duration
+	// ContextDialer used to connect
+	ContextDialer func(context.Context, string) (net.Conn, error)
+	// Hooks can be run before broker Publish/BatchPublish and
+	// Subscribe/BatchSubscribe methods
+	Hooks options.Hooks
 }
 
 // NewCallOptions creates new call options struct
@@ -60,34 +76,47 @@ func NewCallOptions(opts ...CallOption) CallOptions {
 
 // CallOptions holds client call options
 type CallOptions struct {
-	// Address of remote hosts
-	Address []string
-	// Backoff func
-	Backoff BackoffFunc
-	// DialTimeout is the transport Dial Timeout
-	DialTimeout time.Duration
-	// Retries is the number of Call attempts
-	Retries int
-	// Retry func to be used for retries
-	Retry RetryFunc
-	// RequestTimeout specifies request timeout
-	RequestTimeout time.Duration
-	// Router to use for this call
-	Router router.Router
-	// Selector to use for the call
+	// Selector selects addr
 	Selector selector.Selector
-	// SelectOptions to use when selecting a route
-	SelectOptions []selector.SelectOption
-	// StreamTimeout timeout for the stream
-	StreamTimeout time.Duration
-	// AuthToken specifies the auth token as the authorization header
-	AuthToken bool
-	// Network to lookup the route within
-	Network string
-	// CallWrappers is for low level call func
-	CallWrappers []CallWrapper
-	// Context is used for non default options
+	// Context used for deadline
 	Context context.Context
+	// Router used for route
+	Router router.Router
+	// Retry func used for retries
+	Retry RetryFunc
+	// Backoff func used for backoff when retry
+	Backoff BackoffFunc
+	// Network name
+	Network string
+	// Content-Type
+	ContentType string
+	// AuthToken string
+	AuthToken string
+	// Address specifies static addr list
+	Address []string
+	// SelectOptions selector options
+	SelectOptions []selector.SelectOption
+	// StreamTimeout stream timeout
+	StreamTimeout time.Duration
+	// RequestTimeout request timeout
+	RequestTimeout time.Duration
+	// RequestMetadata holds additional metadata for call
+	RequestMetadata metadata.Metadata
+	// ResponseMetadata holds additional metadata from call
+	ResponseMetadata *metadata.Metadata
+	// DialTimeout dial timeout
+	DialTimeout time.Duration
+	// Retries specifies retries num
+	Retries int
+	// ContextDialer used to connect
+	ContextDialer func(context.Context, string) (net.Conn, error)
+}
+
+// ContextDialer pass ContextDialer to client
+func ContextDialer(fn func(context.Context, string) (net.Conn, error)) Option {
+	return func(o *Options) {
+		o.ContextDialer = fn
+	}
 }
 
 // Context pass context to client
@@ -108,15 +137,17 @@ func NewPublishOptions(opts ...PublishOption) PublishOptions {
 
 // PublishOptions holds publish options
 type PublishOptions struct {
-	// Exchange is the routing exchange for the message
-	Exchange string
-	// Context holds additional options
+	// Context used for external options
 	Context context.Context
+	// Exchange topic exchange name
+	Exchange string
+	// BodyOnly will publish only message body
+	BodyOnly bool
 }
 
 // NewMessageOptions creates message options struct
 func NewMessageOptions(opts ...MessageOption) MessageOptions {
-	options := MessageOptions{}
+	options := MessageOptions{Metadata: metadata.New(1)}
 	for _, o := range opts {
 		o(&options)
 	}
@@ -125,6 +156,10 @@ func NewMessageOptions(opts ...MessageOption) MessageOptions {
 
 // MessageOptions holds client message options
 type MessageOptions struct {
+	// Metadata additional metadata
+	Metadata metadata.Metadata
+	// ContentType specify content-type of message
+	// deprecated
 	ContentType string
 }
 
@@ -139,12 +174,12 @@ func NewRequestOptions(opts ...RequestOption) RequestOptions {
 
 // RequestOptions holds client request options
 type RequestOptions struct {
-	// ContentType specify content-type of request
-	ContentType string
-	// Stream says that request is the streaming
-	Stream bool
-	// Context can hold other options
+	// Context used for external options
 	Context context.Context
+	// ContentType specify content-type of message
+	ContentType string
+	// Stream flag
+	Stream bool
 }
 
 // NewOptions creates new options struct
@@ -152,22 +187,25 @@ func NewOptions(opts ...Option) Options {
 	options := Options{
 		Context:     context.Background(),
 		ContentType: DefaultContentType,
-		Codecs:      make(map[string]codec.Codec),
+		Codecs:      DefaultCodecs,
 		CallOptions: CallOptions{
+			Context:        context.Background(),
 			Backoff:        DefaultBackoff,
 			Retry:          DefaultRetry,
 			Retries:        DefaultRetries,
 			RequestTimeout: DefaultRequestTimeout,
 			DialTimeout:    transport.DefaultDialTimeout,
 		},
-		Lookup:   LookupRoute,
-		PoolSize: DefaultPoolSize,
-		PoolTTL:  DefaultPoolTTL,
-		Selector: random.NewSelector(),
-		Logger:   logger.DefaultLogger,
-		Broker:   broker.DefaultBroker,
-		Meter:    meter.DefaultMeter,
-		Tracer:   tracer.DefaultTracer,
+		Lookup:    LookupRoute,
+		PoolSize:  DefaultPoolSize,
+		PoolTTL:   DefaultPoolTTL,
+		Selector:  random.NewSelector(),
+		Logger:    logger.DefaultLogger,
+		Broker:    broker.DefaultBroker,
+		Meter:     meter.DefaultMeter,
+		Tracer:    tracer.DefaultTracer,
+		Router:    router.DefaultRouter,
+		Transport: transport.DefaultTransport,
 	}
 
 	for _, o := range opts {
@@ -251,7 +289,7 @@ func Transport(t transport.Transport) Option {
 func Register(r register.Register) Option {
 	return func(o *Options) {
 		if o.Router != nil {
-			o.Router.Init(router.Register(r))
+			_ = o.Router.Init(router.Register(r))
 		}
 	}
 }
@@ -270,20 +308,6 @@ func Selector(s selector.Selector) Option {
 	}
 }
 
-// Wrap adds a wrapper to the list of options passed into the client
-func Wrap(w Wrapper) Option {
-	return func(o *Options) {
-		o.Wrappers = append(o.Wrappers, w)
-	}
-}
-
-// WrapCall adds a wrapper to the list of CallFunc wrappers
-func WrapCall(cw ...CallWrapper) Option {
-	return func(o *Options) {
-		o.CallOptions.CallWrappers = append(o.CallOptions.CallWrappers, cw...)
-	}
-}
-
 // Backoff is used to set the backoff function used when retrying Calls
 func Backoff(fn BackoffFunc) Option {
 	return func(o *Options) {
@@ -305,6 +329,22 @@ func Lookup(l LookupFunc) Option {
 	}
 }
 
+// TLSConfig specifies a *tls.Config
+func TLSConfig(t *tls.Config) Option {
+	return func(o *Options) {
+		// set the internal tls
+		o.TLSConfig = t
+
+		// set the default transport if one is not
+		// already set. Required for Init call below.
+
+		// set the transport tls
+		_ = o.Transport.Init(
+			transport.TLSConfig(t),
+		)
+	}
+}
+
 // Retries sets the retry count when making the request.
 func Retries(i int) Option {
 	return func(o *Options) {
@@ -341,12 +381,35 @@ func DialTimeout(d time.Duration) Option {
 }
 
 // WithExchange sets the exchange to route a message through
+// Deprecated
 func WithExchange(e string) PublishOption {
 	return func(o *PublishOptions) {
 		o.Exchange = e
 	}
 }
 
+// PublishExchange sets the exchange to route a message through
+func PublishExchange(e string) PublishOption {
+	return func(o *PublishOptions) {
+		o.Exchange = e
+	}
+}
+
+// WithBodyOnly publish only message body
+// DERECATED
+func WithBodyOnly(b bool) PublishOption {
+	return func(o *PublishOptions) {
+		o.BodyOnly = b
+	}
+}
+
+// PublishBodyOnly publish only message body
+func PublishBodyOnly(b bool) PublishOption {
+	return func(o *PublishOptions) {
+		o.BodyOnly = b
+	}
+}
+
 // PublishContext sets the context in publish options
 func PublishContext(ctx context.Context) PublishOption {
 	return func(o *PublishOptions) {
@@ -354,6 +417,20 @@ func PublishContext(ctx context.Context) PublishOption {
 	}
 }
 
+// WithContextDialer pass ContextDialer to client call
+func WithContextDialer(fn func(context.Context, string) (net.Conn, error)) CallOption {
+	return func(o *CallOptions) {
+		o.ContextDialer = fn
+	}
+}
+
+// WithContentType specifies call content type
+func WithContentType(ct string) CallOption {
+	return func(o *CallOptions) {
+		o.ContentType = ct
+	}
+}
+
 // WithAddress sets the remote addresses to use rather than using service discovery
 func WithAddress(a ...string) CallOption {
 	return func(o *CallOptions) {
@@ -361,13 +438,6 @@ func WithAddress(a ...string) CallOption {
 	}
 }
 
-// WithCallWrapper is a CallOption which adds to the existing CallFunc wrappers
-func WithCallWrapper(cw ...CallWrapper) CallOption {
-	return func(o *CallOptions) {
-		o.CallWrappers = append(o.CallWrappers, cw...)
-	}
-}
-
 // WithBackoff is a CallOption which overrides that which
 // set in Options.CallOptions
 func WithBackoff(fn BackoffFunc) CallOption {
@@ -392,6 +462,20 @@ func WithRetries(i int) CallOption {
 	}
 }
 
+// WithResponseMetadata is a CallOption which adds metadata.Metadata to Options.CallOptions
+func WithResponseMetadata(md *metadata.Metadata) CallOption {
+	return func(o *CallOptions) {
+		o.ResponseMetadata = md
+	}
+}
+
+// WithRequestMetadata is a CallOption which adds metadata.Metadata to Options.CallOptions
+func WithRequestMetadata(md metadata.Metadata) CallOption {
+	return func(o *CallOptions) {
+		o.RequestMetadata = md
+	}
+}
+
 // WithRequestTimeout is a CallOption which overrides that which
 // set in Options.CallOptions
 func WithRequestTimeout(d time.Duration) CallOption {
@@ -417,9 +501,9 @@ func WithDialTimeout(d time.Duration) CallOption {
 
 // WithAuthToken is a CallOption which overrides the
 // authorization header with the services own auth token
-func WithAuthToken() CallOption {
+func WithAuthToken(t string) CallOption {
 	return func(o *CallOptions) {
-		o.AuthToken = true
+		o.AuthToken = t
 	}
 }
 
@@ -452,22 +536,46 @@ func WithSelectOptions(sops ...selector.SelectOption) CallOption {
 }
 
 // WithMessageContentType sets the message content type
+// Deprecated
 func WithMessageContentType(ct string) MessageOption {
 	return func(o *MessageOptions) {
+		o.Metadata.Set(metadata.HeaderContentType, ct)
 		o.ContentType = ct
 	}
 }
 
-// WithContentType specifies request content type
-func WithContentType(ct string) RequestOption {
-	return func(o *RequestOptions) {
+// MessageContentType sets the message content type
+func MessageContentType(ct string) MessageOption {
+	return func(o *MessageOptions) {
+		o.Metadata.Set(metadata.HeaderContentType, ct)
 		o.ContentType = ct
 	}
 }
 
+// MessageMetadata sets the message metadata
+func MessageMetadata(k, v string) MessageOption {
+	return func(o *MessageOptions) {
+		o.Metadata.Set(k, v)
+	}
+}
+
 // StreamingRequest specifies that request is streaming
-func StreamingRequest() RequestOption {
+func StreamingRequest(b bool) RequestOption {
 	return func(o *RequestOptions) {
-		o.Stream = true
+		o.Stream = b
+	}
+}
+
+// RequestContentType specifies request content type
+func RequestContentType(ct string) RequestOption {
+	return func(o *RequestOptions) {
+		o.ContentType = ct
+	}
+}
+
+// Hooks sets hook runs before action
+func Hooks(h ...options.Hook) Option {
+	return func(o *Options) {
+		o.Hooks = append(o.Hooks, h...)
 	}
 }

client/retry.go

@@ -3,7 +3,7 @@ package client
 import (
 	"context"
 
-	"github.com/unistack-org/micro/v3/errors"
+	"go.unistack.org/micro/v3/errors"
 )
 
 // RetryFunc that returning either false or a non-nil error will result in the call not being retried
@@ -19,18 +19,32 @@ func RetryNever(ctx context.Context, req Request, retryCount int, err error) (bo
 	return false, nil
 }
 
-// RetryOnError retries a request on a 500 or timeout error
-func RetryOnError(ctx context.Context, req Request, retryCount int, err error) (bool, error) {
+// RetryOnError retries a request on a 500 or 408 (timeout) error
+func RetryOnError(_ context.Context, _ Request, _ int, err error) (bool, error) {
 	if err == nil {
 		return false, nil
 	}
-
 	me := errors.FromError(err)
 	switch me.Code {
 	// retry on timeout or internal server error
 	case 408, 500:
 		return true, nil
 	}
-
 	return false, nil
 }
+
+// RetryOnErrors retries a request on specified error codes
+func RetryOnErrors(codes ...int32) RetryFunc {
+	return func(_ context.Context, _ Request, _ int, err error) (bool, error) {
+		if err == nil {
+			return false, nil
+		}
+		me := errors.FromError(err)
+		for _, code := range codes {
+			if me.Code == code {
+				return true, nil
+			}
+		}
+		return false, nil
+	}
+}

client/retry_test.go

@@ -0,0 +1,70 @@
+package client
+
+import (
+	"context"
+	"fmt"
+	"testing"
+
+	"go.unistack.org/micro/v3/errors"
+)
+
+func TestRetryAlways(t *testing.T) {
+	tests := []error{
+		nil,
+		errors.InternalServerError("test", "%s", "test"),
+		fmt.Errorf("test"),
+	}
+
+	for _, e := range tests {
+		ok, er := RetryAlways(context.TODO(), nil, 1, e)
+		if !ok || er != nil {
+			t.Fatal("RetryAlways not works properly")
+		}
+	}
+}
+
+func TestRetryNever(t *testing.T) {
+	tests := []error{
+		nil,
+		errors.InternalServerError("test", "%s", "test"),
+		fmt.Errorf("test"),
+	}
+
+	for _, e := range tests {
+		ok, er := RetryNever(context.TODO(), nil, 1, e)
+		if ok || er != nil {
+			t.Fatal("RetryNever not works properly")
+		}
+	}
+}
+
+func TestRetryOnError(t *testing.T) {
+	tests := []error{
+		fmt.Errorf("test"),
+		errors.NotFound("test", "%s", "test"),
+		errors.Timeout("test", "%s", "test"),
+	}
+
+	for i, e := range tests {
+		ok, er := RetryOnError(context.TODO(), nil, 1, e)
+		if i == 2 && (!ok || er != nil) {
+			t.Fatal("RetryOnError not works properly")
+		}
+	}
+}
+
+func TestRetryOnErrors(t *testing.T) {
+	tests := []error{
+		fmt.Errorf("test"),
+		errors.NotFound("test", "%s", "test"),
+		errors.Timeout("test", "%s", "test"),
+	}
+
+	fn := RetryOnErrors(404)
+	for i, e := range tests {
+		ok, er := fn(context.TODO(), nil, 1, e)
+		if i == 1 && (!ok || er != nil) {
+			t.Fatal("RetryOnErrors not works properly")
+		}
+	}
+}

client/test_request.go

@@ -1,16 +1,16 @@
 package client
 
 import (
-	"github.com/unistack-org/micro/v3/codec"
+	"go.unistack.org/micro/v3/codec"
 )
 
 type testRequest struct {
+	codec       codec.Codec
+	body        interface{}
 	service     string
 	method      string
 	endpoint    string
 	contentType string
-	codec       codec.Codec
-	body        interface{}
 	opts        RequestOptions
 }
 

cluster/cluster.go

@@ -0,0 +1,41 @@
+package cluster
+
+import (
+	"context"
+
+	"go.unistack.org/micro/v3/metadata"
+)
+
+// Message sent to member in cluster
+type Message interface {
+	// Header returns message headers
+	Header() metadata.Metadata
+	// Body returns broker message may be []byte slice or some go struct or interface
+	Body() interface{}
+}
+
+type Node interface {
+	// Name returns node name
+	Name() string
+	// Address returns node address
+	Address() string
+	// Metadata returns node metadata
+	Metadata() metadata.Metadata
+}
+
+// Cluster interface used for cluster communication across nodes
+type Cluster interface {
+	// Join is used to take an existing members and performing state sync
+	Join(ctx context.Context, addr ...string) error
+	// Leave broadcast a leave message and stop listeners
+	Leave(ctx context.Context) error
+	// Ping is used to probe live status of the node
+	Ping(ctx context.Context, node Node, payload []byte) error
+	// Members returns the cluster members
+	Members() ([]Node, error)
+	// Broadcast send message for all members in cluster, if filter is not nil, nodes may be filtered
+	// by key/value pairs
+	Broadcast(ctx context.Context, msg Message, filter ...string) error
+	// Unicast send message to single member in cluster
+	Unicast(ctx context.Context, node Node, msg Message) error
+}

codec/codec.go

@@ -1,11 +1,11 @@
 // Package codec is an interface for encoding messages
-package codec
+package codec // import "go.unistack.org/micro/v3/codec"
 
 import (
 	"errors"
 	"io"
 
-	"github.com/unistack-org/micro/v3/metadata"
+	"go.unistack.org/micro/v3/metadata"
 )
 
 // Message types
@@ -25,9 +25,11 @@ var (
 
 var (
 	// DefaultMaxMsgSize specifies how much data codec can handle
-	DefaultMaxMsgSize int = 1024 * 1024 * 4 // 4Mb
+	DefaultMaxMsgSize = 1024 * 1024 * 4 // 4Mb
 	// DefaultCodec is the global default codec
-	DefaultCodec Codec = NewCodec()
+	DefaultCodec = NewCodec()
+	// DefaultTagName specifies struct tag name to control codec Marshal/Unmarshal
+	DefaultTagName = "codec"
 )
 
 // MessageType specifies message type for codec
@@ -39,11 +41,11 @@ type MessageType int
 // connection. ReadBody may be called with a nil argument to force the
 // body to be read and discarded.
 type Codec interface {
-	ReadHeader(io.Reader, *Message, MessageType) error
-	ReadBody(io.Reader, interface{}) error
-	Write(io.Writer, *Message, interface{}) error
-	Marshal(interface{}) ([]byte, error)
-	Unmarshal([]byte, interface{}) error
+	ReadHeader(r io.Reader, m *Message, mt MessageType) error
+	ReadBody(r io.Reader, v interface{}) error
+	Write(w io.Writer, m *Message, v interface{}) error
+	Marshal(v interface{}, opts ...Option) ([]byte, error)
+	Unmarshal(b []byte, v interface{}, opts ...Option) error
 	String() string
 }
 
@@ -51,19 +53,55 @@ type Codec interface {
 // the communication, likely followed by the body.
 // In the case of an error, body may be nil.
 type Message struct {
-	Id       string
-	Type     MessageType
+	Header   metadata.Metadata
 	Target   string
 	Method   string
 	Endpoint string
 	Error    string
-
-	// The values read from the socket
-	Header metadata.Metadata
-	Body   []byte
+	ID       string
+	Body     []byte
+	Type     MessageType
 }
 
 // NewMessage creates new codec message
 func NewMessage(t MessageType) *Message {
 	return &Message{Type: t, Header: metadata.New(0)}
 }
+
+// MarshalAppend calls codec.Marshal(v) and returns the data appended to buf.
+// If codec implements MarshalAppend, that is called instead.
+func MarshalAppend(buf []byte, c Codec, v interface{}, opts ...Option) ([]byte, error) {
+	if nc, ok := c.(interface {
+		MarshalAppend([]byte, interface{}, ...Option) ([]byte, error)
+	}); ok {
+		return nc.MarshalAppend(buf, v, opts...)
+	}
+
+	mbuf, err := c.Marshal(v, opts...)
+	if err != nil {
+		return nil, err
+	}
+
+	return append(buf, mbuf...), nil
+}
+
+// RawMessage is a raw encoded JSON value.
+// It implements Marshaler and Unmarshaler and can be used to delay decoding or precompute a encoding.
+type RawMessage []byte
+
+// MarshalJSON returns m as the JSON encoding of m.
+func (m *RawMessage) MarshalJSON() ([]byte, error) {
+	if m == nil {
+		return []byte("null"), nil
+	}
+	return *m, nil
+}
+
+// UnmarshalJSON sets *m to a copy of data.
+func (m *RawMessage) UnmarshalJSON(data []byte) error {
+	if m == nil {
+		return errors.New("RawMessage UnmarshalJSON on nil pointer")
+	}
+	*m = append((*m)[0:0], data...)
+	return nil
+}

codec/context.go

@@ -0,0 +1,34 @@
+package codec
+
+import (
+	"context"
+)
+
+type codecKey struct{}
+
+// FromContext returns codec from context
+func FromContext(ctx context.Context) (Codec, bool) {
+	if ctx == nil {
+		return nil, false
+	}
+	c, ok := ctx.Value(codecKey{}).(Codec)
+	return c, ok
+}
+
+// NewContext put codec in context
+func NewContext(ctx context.Context, c Codec) context.Context {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	return context.WithValue(ctx, codecKey{}, c)
+}
+
+// SetOption returns a function to setup a context with given value
+func SetOption(k, v interface{}) Option {
+	return func(o *Options) {
+		if o.Context == nil {
+			o.Context = context.Background()
+		}
+		o.Context = context.WithValue(o.Context, k, v)
+	}
+}

codec/context_test.go

@@ -0,0 +1,35 @@
+package codec
+
+import (
+	"context"
+	"testing"
+)
+
+func TestFromContext(t *testing.T) {
+	ctx := context.WithValue(context.TODO(), codecKey{}, NewCodec())
+
+	c, ok := FromContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("FromContext not works")
+	}
+}
+
+func TestNewContext(t *testing.T) {
+	ctx := NewContext(context.TODO(), NewCodec())
+
+	c, ok := FromContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("NewContext not works")
+	}
+}
+
+func TestSetOption(t *testing.T) {
+	type key struct{}
+	o := SetOption(key{}, "test")
+	opts := &Options{}
+	o(opts)
+
+	if v, ok := opts.Context.Value(key{}).(string); !ok || v == "" {
+		t.Fatal("SetOption not works")
+	}
+}

codec/frame.go

@@ -0,0 +1,45 @@
+package codec
+
+// Frame gives us the ability to define raw data to send over the pipes
+type Frame struct {
+	Data []byte
+}
+
+// NewFrame returns new frame with data
+func NewFrame(data []byte) *Frame {
+	return &Frame{Data: data}
+}
+
+// MarshalJSON returns frame data
+func (m *Frame) MarshalJSON() ([]byte, error) {
+	return m.Marshal()
+}
+
+// UnmarshalJSON set frame data
+func (m *Frame) UnmarshalJSON(data []byte) error {
+	return m.Unmarshal(data)
+}
+
+// ProtoMessage noop func
+func (m *Frame) ProtoMessage() {}
+
+// Reset resets frame
+func (m *Frame) Reset() {
+	*m = Frame{}
+}
+
+// String returns frame as string
+func (m *Frame) String() string {
+	return string(m.Data)
+}
+
+// Marshal returns frame data
+func (m *Frame) Marshal() ([]byte, error) {
+	return m.Data, nil
+}
+
+// Unmarshal set frame data
+func (m *Frame) Unmarshal(data []byte) error {
+	m.Data = data
+	return nil
+}

codec/frame.proto

@@ -0,0 +1,28 @@
+// Copyright 2021 Unistack LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+syntax = "proto3";
+
+package micro.codec;
+
+option cc_enable_arenas = true;
+option go_package = "go.unistack.org/micro/v3/codec;codec";
+option java_multiple_files = true;
+option java_outer_classname = "MicroCodec";
+option java_package = "micro.codec";
+option objc_class_prefix = "MCODEC";
+
+message Frame {
+  bytes data = 1;
+}

codec/noop.go

@@ -6,11 +6,7 @@ import (
 )
 
 type noopCodec struct {
-}
-
-// Frame gives us the ability to define raw data to send over the pipes
-type Frame struct {
-	Data []byte
+	opts Options
 }
 
 func (c *noopCodec) ReadHeader(conn io.Reader, m *Message, t MessageType) error {
@@ -75,11 +71,11 @@ func (c *noopCodec) String() string {
 }
 
 // NewCodec returns new noop codec
-func NewCodec() Codec {
-	return &noopCodec{}
+func NewCodec(opts ...Option) Codec {
+	return &noopCodec{opts: NewOptions(opts...)}
 }
 
-func (c *noopCodec) Marshal(v interface{}) ([]byte, error) {
+func (c *noopCodec) Marshal(v interface{}, opts ...Option) ([]byte, error) {
 	if v == nil {
 		return nil, nil
 	}
@@ -102,7 +98,7 @@ func (c *noopCodec) Marshal(v interface{}) ([]byte, error) {
 	return json.Marshal(v)
 }
 
-func (c *noopCodec) Unmarshal(d []byte, v interface{}) error {
+func (c *noopCodec) Unmarshal(d []byte, v interface{}, opts ...Option) error {
 	if v == nil {
 		return nil
 	}
@@ -110,6 +106,9 @@ func (c *noopCodec) Unmarshal(d []byte, v interface{}) error {
 	case *string:
 		*ve = string(d)
 		return nil
+	case []byte:
+		copy(ve, d)
+		return nil
 	case *[]byte:
 		*ve = d
 		return nil

codec/noop_test.go

@@ -5,7 +5,7 @@ import (
 	"testing"
 )
 
-func TestNoopBytes(t *testing.T) {
+func TestNoopBytesPtr(t *testing.T) {
 	req := []byte("test req")
 	rsp := make([]byte, len(req))
 
@@ -19,6 +19,20 @@ func TestNoopBytes(t *testing.T) {
 	}
 }
 
+func TestNoopBytes(t *testing.T) {
+	req := []byte("test req")
+	var rsp []byte
+
+	nc := NewCodec()
+	if err := nc.Unmarshal(req, &rsp); err != nil {
+		t.Fatal(err)
+	}
+
+	if !bytes.Equal(req, rsp) {
+		t.Fatalf("req not eq rsp: %s != %s", req, rsp)
+	}
+}
+
 func TestNoopString(t *testing.T) {
 	req := []byte("test req")
 	var rsp string

codec/options.go

@@ -1,9 +1,11 @@
 package codec
 
 import (
-	"github.com/unistack-org/micro/v3/logger"
-	"github.com/unistack-org/micro/v3/meter"
-	"github.com/unistack-org/micro/v3/tracer"
+	"context"
+
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v3/tracer"
 )
 
 // Option func
@@ -11,10 +13,18 @@ type Option func(*Options)
 
 // Options contains codec options
 type Options struct {
+	// Meter used for metrics
+	Meter meter.Meter
+	// Logger used for logging
+	Logger logger.Logger
+	// Tracer used for tracing
+	Tracer tracer.Tracer
+	// Context stores additional codec options
+	Context context.Context
+	// TagName specifies tag name in struct to control codec
+	TagName string
+	// MaxMsgSize specifies max messages size that reads by codec
 	MaxMsgSize int
-	Meter      meter.Meter
-	Logger     logger.Logger
-	Tracer     tracer.Tracer
 }
 
 // MaxMsgSize sets the max message size
@@ -24,6 +34,13 @@ func MaxMsgSize(n int) Option {
 	}
 }
 
+// TagName sets the codec tag name in struct
+func TagName(n string) Option {
+	return func(o *Options) {
+		o.TagName = n
+	}
+}
+
 // Logger sets the logger
 func Logger(l logger.Logger) Option {
 	return func(o *Options) {
@@ -48,10 +65,12 @@ func Meter(m meter.Meter) Option {
 // NewOptions returns new options
 func NewOptions(opts ...Option) Options {
 	options := Options{
+		Context:    context.Background(),
 		Logger:     logger.DefaultLogger,
 		Meter:      meter.DefaultMeter,
 		Tracer:     tracer.DefaultTracer,
 		MaxMsgSize: DefaultMaxMsgSize,
+		TagName:    DefaultTagName,
 	}
 
 	for _, o := range opts {

config/config.go

@@ -1,15 +1,25 @@
 // Package config is an interface for dynamic configuration.
-package config
+package config // import "go.unistack.org/micro/v3/config"
 
 import (
 	"context"
 	"errors"
+	"reflect"
+	"time"
 )
 
-var (
-	// DefaultConfig default config
-	DefaultConfig Config = NewConfig()
-)
+type Validator interface {
+	Validate() error
+}
+
+// DefaultConfig default config
+var DefaultConfig Config = NewConfig()
+
+// DefaultWatcherMinInterval default min interval for poll changes
+var DefaultWatcherMinInterval = 5 * time.Second
+
+// DefaultWatcherMaxInterval default max interval for poll changes
+var DefaultWatcherMaxInterval = 9 * time.Second
 
 var (
 	// ErrCodecMissing is returned when codec needed and not specified
@@ -18,40 +28,197 @@ var (
 	ErrInvalidStruct = errors.New("invalid struct specified")
 	// ErrWatcherStopped is returned when source watcher has been stopped
 	ErrWatcherStopped = errors.New("watcher stopped")
+	// ErrWatcherNotImplemented returned when config does not implement watch
+	ErrWatcherNotImplemented = errors.New("watcher not implemented")
 )
 
 // Config is an interface abstraction for dynamic configuration
 type Config interface {
+	// Name returns name of config
 	Name() string
 	// Init the config
 	Init(opts ...Option) error
 	// Options in the config
 	Options() Options
 	// Load config from sources
-	Load(context.Context) error
+	Load(context.Context, ...LoadOption) error
 	// Save config to sources
-	Save(context.Context) error
-	// Watch a value for changes
-	//	Watch(interface{}) (Watcher, error)
+	Save(context.Context, ...SaveOption) error
+	// Watch a config for changes
+	Watch(context.Context, ...WatchOption) (Watcher, error)
+	// String returns config type name
 	String() string
 }
 
+type (
+	FuncLoad func(ctx context.Context, opts ...LoadOption) error
+	HookLoad func(next FuncLoad) FuncLoad
+	FuncSave func(ctx context.Context, opts ...SaveOption) error
+	HookSave func(next FuncSave) FuncSave
+)
+
 // Watcher is the config watcher
-//type Watcher interface {
-//	Next() (, error)
-//	Stop() error
-//}
+type Watcher interface {
+	// Next blocks until update happens or error returned
+	Next() (map[string]interface{}, error)
+	// Stop stops watcher
+	Stop() error
+}
 
 // Load loads config from config sources
-func Load(ctx context.Context, cs ...Config) error {
+func Load(ctx context.Context, cs []Config, opts ...LoadOption) error {
 	var err error
 	for _, c := range cs {
 		if err = c.Init(); err != nil {
 			return err
 		}
-		if err = c.Load(ctx); err != nil {
+		if err = c.Load(ctx, opts...); err != nil {
 			return err
 		}
 	}
 	return nil
 }
+
+// Validate runs Validate() error func for each struct field
+func Validate(ctx context.Context, cfg interface{}) error {
+	if cfg == nil {
+		return nil
+	}
+
+	if v, ok := cfg.(Validator); ok {
+		if err := v.Validate(); err != nil {
+			return err
+		}
+	}
+
+	sv := reflect.ValueOf(cfg)
+	if sv.Kind() == reflect.Ptr {
+		sv = sv.Elem()
+	}
+	if sv.Kind() != reflect.Struct {
+		return nil
+	}
+
+	typ := sv.Type()
+	for idx := 0; idx < typ.NumField(); idx++ {
+		fld := typ.Field(idx)
+		val := sv.Field(idx)
+		if !val.IsValid() || len(fld.PkgPath) != 0 {
+			continue
+		}
+
+		if v, ok := val.Interface().(Validator); ok {
+			if err := v.Validate(); err != nil {
+				return err
+			}
+		}
+
+		switch val.Kind() {
+		case reflect.Ptr:
+			if reflect.Indirect(val).Kind() == reflect.Struct {
+				if err := Validate(ctx, val.Interface()); err != nil {
+					return err
+				}
+			}
+		case reflect.Struct:
+			if err := Validate(ctx, val.Interface()); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+var (
+	// DefaultBeforeLoad default func that runs before config Load
+	DefaultBeforeLoad = func(ctx context.Context, c Config) error {
+		for _, fn := range c.Options().BeforeLoad {
+			if fn == nil {
+				return nil
+			}
+			if err := fn(ctx, c); err != nil {
+				c.Options().Logger.Errorf(ctx, "%s BeforeLoad err: %v", c.String(), err)
+				if !c.Options().AllowFail {
+					return err
+				}
+			}
+		}
+		return nil
+	}
+	// DefaultAfterLoad default func that runs after config Load
+	DefaultAfterLoad = func(ctx context.Context, c Config) error {
+		for _, fn := range c.Options().AfterLoad {
+			if fn == nil {
+				return nil
+			}
+			if err := fn(ctx, c); err != nil {
+				c.Options().Logger.Errorf(ctx, "%s AfterLoad err: %v", c.String(), err)
+				if !c.Options().AllowFail {
+					return err
+				}
+			}
+		}
+		return nil
+	}
+	// DefaultBeforeSave default func that runs befora config Save
+	DefaultBeforeSave = func(ctx context.Context, c Config) error {
+		for _, fn := range c.Options().BeforeSave {
+			if fn == nil {
+				return nil
+			}
+			if err := fn(ctx, c); err != nil {
+				c.Options().Logger.Errorf(ctx, "%s BeforeSave err: %v", c.String(), err)
+				if !c.Options().AllowFail {
+					return err
+				}
+			}
+		}
+		return nil
+	}
+	// DefaultAfterSave default func that runs after config Save
+	DefaultAfterSave = func(ctx context.Context, c Config) error {
+		for _, fn := range c.Options().AfterSave {
+			if fn == nil {
+				return nil
+			}
+			if err := fn(ctx, c); err != nil {
+				c.Options().Logger.Errorf(ctx, "%s AfterSave err: %v", c.String(), err)
+				if !c.Options().AllowFail {
+					return err
+				}
+			}
+		}
+		return nil
+	}
+	// DefaultBeforeInit default func that runs befora config Init
+	DefaultBeforeInit = func(ctx context.Context, c Config) error {
+		for _, fn := range c.Options().BeforeInit {
+			if fn == nil {
+				return nil
+			}
+			if err := fn(ctx, c); err != nil {
+				c.Options().Logger.Errorf(ctx, "%s BeforeInit err: %v", c.String(), err)
+				if !c.Options().AllowFail {
+					return err
+				}
+			}
+		}
+		return nil
+	}
+	// DefaultAfterInit default func that runs after config Init
+	DefaultAfterInit = func(ctx context.Context, c Config) error {
+		for _, fn := range c.Options().AfterSave {
+			if fn == nil {
+				return nil
+			}
+			if err := fn(ctx, c); err != nil {
+				c.Options().Logger.Errorf(ctx, "%s AfterInit err: %v", c.String(), err)
+				if !c.Options().AllowFail {
+					return err
+				}
+			}
+		}
+		return nil
+	}
+)

config/context.go

@@ -32,3 +32,33 @@ func SetOption(k, v interface{}) Option {
 		o.Context = context.WithValue(o.Context, k, v)
 	}
 }
+
+// SetSaveOption returns a function to setup a context with given value
+func SetSaveOption(k, v interface{}) SaveOption {
+	return func(o *SaveOptions) {
+		if o.Context == nil {
+			o.Context = context.Background()
+		}
+		o.Context = context.WithValue(o.Context, k, v)
+	}
+}
+
+// SetLoadOption returns a function to setup a context with given value
+func SetLoadOption(k, v interface{}) LoadOption {
+	return func(o *LoadOptions) {
+		if o.Context == nil {
+			o.Context = context.Background()
+		}
+		o.Context = context.WithValue(o.Context, k, v)
+	}
+}
+
+// SetWatchOption returns a function to setup a context with given value
+func SetWatchOption(k, v interface{}) WatchOption {
+	return func(o *WatchOptions) {
+		if o.Context == nil {
+			o.Context = context.Background()
+		}
+		o.Context = context.WithValue(o.Context, k, v)
+	}
+}

config/context_test.go

@@ -0,0 +1,86 @@
+package config
+
+import (
+	"context"
+	"testing"
+)
+
+func TestFromNilContext(t *testing.T) {
+	// nolint: staticcheck
+	c, ok := FromContext(nil)
+	if ok || c != nil {
+		t.Fatal("FromContext not works")
+	}
+}
+
+func TestNewNilContext(t *testing.T) {
+	// nolint: staticcheck
+	ctx := NewContext(nil, NewConfig())
+
+	c, ok := FromContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("NewContext not works")
+	}
+}
+
+func TestFromContext(t *testing.T) {
+	ctx := context.WithValue(context.TODO(), configKey{}, NewConfig())
+
+	c, ok := FromContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("FromContext not works")
+	}
+}
+
+func TestNewContext(t *testing.T) {
+	ctx := NewContext(context.TODO(), NewConfig())
+
+	c, ok := FromContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("NewContext not works")
+	}
+}
+
+func TestSetOption(t *testing.T) {
+	type key struct{}
+	o := SetOption(key{}, "test")
+	opts := &Options{}
+	o(opts)
+
+	if v, ok := opts.Context.Value(key{}).(string); !ok || v == "" {
+		t.Fatal("SetOption not works")
+	}
+}
+
+func TestSetSaveOption(t *testing.T) {
+	type key struct{}
+	o := SetSaveOption(key{}, "test")
+	opts := &SaveOptions{}
+	o(opts)
+
+	if v, ok := opts.Context.Value(key{}).(string); !ok || v == "" {
+		t.Fatal("SetSaveOption not works")
+	}
+}
+
+func TestSetLoadOption(t *testing.T) {
+	type key struct{}
+	o := SetLoadOption(key{}, "test")
+	opts := &LoadOptions{}
+	o(opts)
+
+	if v, ok := opts.Context.Value(key{}).(string); !ok || v == "" {
+		t.Fatal("SetLoadOption not works")
+	}
+}
+
+func TestSetWatchOption(t *testing.T) {
+	type key struct{}
+	o := SetWatchOption(key{}, "test")
+	opts := &WatchOptions{}
+	o(opts)
+
+	if v, ok := opts.Context.Value(key{}).(string); !ok || v == "" {
+		t.Fatal("SetWatchOption not works")
+	}
+}

config/default.go

@@ -5,13 +5,20 @@ import (
 	"reflect"
 	"strconv"
 	"strings"
+	"time"
 
-	"github.com/imdario/mergo"
-	rutil "github.com/unistack-org/micro/v3/util/reflect"
+	"dario.cat/mergo"
+	"github.com/google/uuid"
+	"go.unistack.org/micro/v3/options"
+	mid "go.unistack.org/micro/v3/util/id"
+	rutil "go.unistack.org/micro/v3/util/reflect"
+	mtime "go.unistack.org/micro/v3/util/time"
 )
 
 type defaultConfig struct {
-	opts Options
+	funcLoad FuncLoad
+	funcSave FuncSave
+	opts     Options
 }
 
 func (c *defaultConfig) Options() Options {
@@ -22,42 +29,90 @@ func (c *defaultConfig) Init(opts ...Option) error {
 	for _, o := range opts {
 		o(&c.opts)
 	}
+
+	if err := DefaultBeforeInit(c.opts.Context, c); err != nil && !c.opts.AllowFail {
+		return err
+	}
+
+	c.funcLoad = c.fnLoad
+	c.funcSave = c.fnSave
+
+	c.opts.Hooks.EachNext(func(hook options.Hook) {
+		switch h := hook.(type) {
+		case HookLoad:
+			c.funcLoad = h(c.funcLoad)
+		case HookSave:
+			c.funcSave = h(c.funcSave)
+		}
+	})
+
+	if err := DefaultAfterInit(c.opts.Context, c); err != nil && !c.opts.AllowFail {
+		return err
+	}
+
 	return nil
 }
 
-func (c *defaultConfig) Load(ctx context.Context) error {
-	for _, fn := range c.opts.BeforeLoad {
-		if err := fn(ctx, c); err != nil && !c.opts.AllowFail {
+func (c *defaultConfig) Load(ctx context.Context, opts ...LoadOption) error {
+	return c.funcLoad(ctx, opts...)
+}
+
+func (c *defaultConfig) fnLoad(ctx context.Context, opts ...LoadOption) error {
+	var err error
+
+	if c.opts.SkipLoad != nil && c.opts.SkipLoad(ctx, c) {
+		return nil
+	}
+
+	if err = DefaultBeforeLoad(ctx, c); err != nil && !c.opts.AllowFail {
+		return err
+	}
+
+	options := NewLoadOptions(opts...)
+	mopts := []func(*mergo.Config){mergo.WithTypeCheck}
+	if options.Override {
+		mopts = append(mopts, mergo.WithOverride)
+	}
+	if options.Append {
+		mopts = append(mopts, mergo.WithAppendSlice)
+	}
+
+	dst := c.opts.Struct
+	if options.Struct != nil {
+		dst = options.Struct
+	}
+
+	src, err := rutil.Zero(dst)
+	if err != nil {
+		if !c.opts.AllowFail {
+			return err
+		}
+		if err = DefaultAfterLoad(ctx, c); err != nil && !c.opts.AllowFail {
 			return err
 		}
 	}
 
-	src, err := rutil.Zero(c.opts.Struct)
-	if err == nil {
-		valueOf := reflect.ValueOf(src)
-		if err = c.fillValues(ctx, valueOf); err == nil {
-			err = mergo.Merge(c.opts.Struct, src, mergo.WithOverride, mergo.WithTypeCheck, mergo.WithAppendSlice)
-		}
+	if err = fillValues(reflect.ValueOf(src), c.opts.StructTag); err == nil {
+		err = mergo.Merge(dst, src, mopts...)
 	}
 
 	if err != nil && !c.opts.AllowFail {
 		return err
 	}
 
-	for _, fn := range c.opts.AfterLoad {
-		if err := fn(ctx, c); err != nil && !c.opts.AllowFail {
-			return err
-		}
+	if err := DefaultAfterLoad(ctx, c); err != nil && !c.opts.AllowFail {
+		return err
 	}
 
 	return nil
 }
 
 //nolint:gocyclo
-func (c *defaultConfig) fillValue(ctx context.Context, value reflect.Value, val string) error {
+func fillValue(value reflect.Value, val string) error {
 	if !rutil.IsEmpty(value) {
 		return nil
 	}
+
 	switch value.Kind() {
 	case reflect.Map:
 		t := value.Type()
@@ -71,10 +126,10 @@ func (c *defaultConfig) fillValue(ctx context.Context, value reflect.Value, val
 			kv := strings.FieldsFunc(nval, func(c rune) bool { return c == '=' })
 			mkey := reflect.Indirect(reflect.New(kt))
 			mval := reflect.Indirect(reflect.New(et))
-			if err := c.fillValue(ctx, mkey, kv[0]); err != nil {
+			if err := fillValue(mkey, kv[0]); err != nil {
 				return err
 			}
-			if err := c.fillValue(ctx, mval, kv[1]); err != nil {
+			if err := fillValue(mval, kv[1]); err != nil {
 				return err
 			}
 			value.SetMapIndex(mkey, mval)
@@ -84,7 +139,7 @@ func (c *defaultConfig) fillValue(ctx context.Context, value reflect.Value, val
 		value.Set(reflect.MakeSlice(reflect.SliceOf(value.Type().Elem()), len(nvals), len(nvals)))
 		for idx, nval := range nvals {
 			nvalue := reflect.Indirect(reflect.New(value.Type().Elem()))
-			if err := c.fillValue(ctx, nvalue, nval); err != nil {
+			if err := fillValue(nvalue, nval); err != nil {
 				return err
 			}
 			value.Index(idx).Set(nvalue)
@@ -96,6 +151,20 @@ func (c *defaultConfig) fillValue(ctx context.Context, value reflect.Value, val
 		}
 		value.Set(reflect.ValueOf(v))
 	case reflect.String:
+		switch val {
+		case "micro:generate uuid":
+			uid, err := uuid.NewRandom()
+			if err != nil {
+				return err
+			}
+			val = uid.String()
+		case "micro:generate id":
+			uid, err := mid.New()
+			if err != nil {
+				return err
+			}
+			val = uid
+		}
 		value.Set(reflect.ValueOf(val))
 	case reflect.Float32:
 		v, err := strconv.ParseFloat(val, 32)
@@ -134,11 +203,26 @@ func (c *defaultConfig) fillValue(ctx context.Context, value reflect.Value, val
 		}
 		value.Set(reflect.ValueOf(int32(v)))
 	case reflect.Int64:
-		v, err := strconv.ParseInt(val, 10, 64)
-		if err != nil {
-			return err
+		switch {
+		case value.Type().String() == "time.Duration" && value.Type().PkgPath() == "time":
+			v, err := time.ParseDuration(val)
+			if err != nil {
+				return err
+			}
+			value.Set(reflect.ValueOf(v))
+		case value.Type().String() == "time.Duration" && value.Type().PkgPath() == "go.unistack.org/micro/v3/util/time":
+			v, err := mtime.ParseDuration(val)
+			if err != nil {
+				return err
+			}
+			value.SetInt(int64(v))
+		default:
+			v, err := strconv.ParseInt(val, 10, 64)
+			if err != nil {
+				return err
+			}
+			value.Set(reflect.ValueOf(v))
 		}
-		value.Set(reflect.ValueOf(v))
 	case reflect.Uint:
 		v, err := strconv.ParseUint(val, 10, 0)
 		if err != nil {
@@ -170,10 +254,11 @@ func (c *defaultConfig) fillValue(ctx context.Context, value reflect.Value, val
 		}
 		value.Set(reflect.ValueOf(v))
 	}
+
 	return nil
 }
 
-func (c *defaultConfig) fillValues(ctx context.Context, valueOf reflect.Value) error {
+func fillValues(valueOf reflect.Value, tname string) error {
 	var values reflect.Value
 
 	if valueOf.Kind() == reflect.Ptr {
@@ -200,7 +285,7 @@ func (c *defaultConfig) fillValues(ctx context.Context, valueOf reflect.Value) e
 		switch value.Kind() {
 		case reflect.Struct:
 			value.Set(reflect.Indirect(reflect.New(value.Type())))
-			if err := c.fillValues(ctx, value); err != nil {
+			if err := fillValues(value, tname); err != nil {
 				return err
 			}
 			continue
@@ -214,17 +299,17 @@ func (c *defaultConfig) fillValues(ctx context.Context, valueOf reflect.Value) e
 				value.Set(reflect.New(value.Type().Elem()))
 			}
 			value = value.Elem()
-			if err := c.fillValues(ctx, value); err != nil {
+			if err := fillValues(value, tname); err != nil {
 				return err
 			}
 			continue
 		}
-		tag, ok := field.Tag.Lookup(c.opts.StructTag)
+		tag, ok := field.Tag.Lookup(tname)
 		if !ok {
 			continue
 		}
 
-		if err := c.fillValue(ctx, value, tag); err != nil {
+		if err := fillValue(value, tag); err != nil {
 			return err
 		}
 	}
@@ -232,17 +317,21 @@ func (c *defaultConfig) fillValues(ctx context.Context, valueOf reflect.Value) e
 	return nil
 }
 
-func (c *defaultConfig) Save(ctx context.Context) error {
-	for _, fn := range c.opts.BeforeSave {
-		if err := fn(ctx, c); err != nil && !c.opts.AllowFail {
-			return err
-		}
+func (c *defaultConfig) Save(ctx context.Context, opts ...SaveOption) error {
+	return c.funcSave(ctx, opts...)
+}
+
+func (c *defaultConfig) fnSave(ctx context.Context, opts ...SaveOption) error {
+	if c.opts.SkipSave != nil && c.opts.SkipSave(ctx, c) {
+		return nil
 	}
 
-	for _, fn := range c.opts.AfterSave {
-		if err := fn(ctx, c); err != nil && !c.opts.AllowFail {
-			return err
-		}
+	if err := DefaultBeforeSave(ctx, c); err != nil {
+		return err
+	}
+
+	if err := DefaultAfterSave(ctx, c); err != nil {
+		return err
 	}
 
 	return nil
@@ -256,11 +345,19 @@ func (c *defaultConfig) Name() string {
 	return c.opts.Name
 }
 
+func (c *defaultConfig) Watch(_ context.Context, _ ...WatchOption) (Watcher, error) {
+	return nil, ErrWatcherNotImplemented
+}
+
 // NewConfig returns new default config source
 func NewConfig(opts ...Option) Config {
 	options := NewOptions(opts...)
 	if len(options.StructTag) == 0 {
 		options.StructTag = "default"
 	}
-	return &defaultConfig{opts: options}
+	c := &defaultConfig{opts: options}
+	c.funcLoad = c.fnLoad
+	c.funcSave = c.fnSave
+
+	return c
 }

config/default_test.go

@@ -4,36 +4,89 @@ import (
 	"context"
 	"fmt"
 	"testing"
+	"time"
 
-	"github.com/unistack-org/micro/v3/config"
+	"go.unistack.org/micro/v3/config"
+	mid "go.unistack.org/micro/v3/util/id"
+	mtime "go.unistack.org/micro/v3/util/time"
 )
 
-type Cfg struct {
+type cfg struct {
+	StringValue    string `default:"string_value"`
+	IgnoreValue    string `json:"-"`
+	StructValue    *cfgStructValue
+	IntValue       int             `default:"99"`
+	DurationValue  time.Duration   `default:"10s"`
+	MDurationValue mtime.Duration  `default:"10s"`
+	MapValue       map[string]bool `default:"key1=true,key2=false"`
+	UUIDValue      string          `default:"micro:generate uuid"`
+	IDValue        string          `default:"micro:generate id"`
+}
+
+type cfgStructValue struct {
 	StringValue string `default:"string_value"`
-	IntValue    int    `default:"99"`
-	IgnoreValue string `json:"-"`
-	StructValue struct {
-		StringValue string `default:"string_value"`
+}
+
+func (c *cfg) Validate() error {
+	if c.IntValue != 10 {
+		return fmt.Errorf("invalid IntValue %d != %d", 10, c.IntValue)
+	}
+	return nil
+}
+
+func (c *cfgStructValue) Validate() error {
+	if c.StringValue != "string_value" {
+		return fmt.Errorf("invalid StringValue %s != %s", "string_value", c.StringValue)
+	}
+	return nil
+}
+
+type testHook struct {
+	f bool
+}
+
+func (t *testHook) Load(fn config.FuncLoad) config.FuncLoad {
+	return func(ctx context.Context, opts ...config.LoadOption) error {
+		t.f = true
+		return fn(ctx, opts...)
+	}
+}
+
+func TestHook(t *testing.T) {
+	h := &testHook{}
+
+	c := config.NewConfig(config.Struct(h), config.Hooks(config.HookLoad(h.Load)))
+
+	if err := c.Init(); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := c.Load(context.TODO()); err != nil {
+		t.Fatal(err)
+	}
+
+	if !h.f {
+		t.Fatal("hook not works")
 	}
 }
 
 func TestDefault(t *testing.T) {
 	ctx := context.Background()
-	conf := &Cfg{IntValue: 10}
-	blfn := func(ctx context.Context, cfg config.Config) error {
-		conf, ok := cfg.Options().Struct.(*Cfg)
+	conf := &cfg{IntValue: 10}
+	blfn := func(_ context.Context, c config.Config) error {
+		nconf, ok := c.Options().Struct.(*cfg)
 		if !ok {
-			return fmt.Errorf("failed to get Struct from options: %v", cfg.Options())
+			return fmt.Errorf("failed to get Struct from options: %v", c.Options())
 		}
-		conf.StringValue = "before_load"
+		nconf.StringValue = "before_load"
 		return nil
 	}
-	alfn := func(ctx context.Context, cfg config.Config) error {
-		conf, ok := cfg.Options().Struct.(*Cfg)
+	alfn := func(_ context.Context, c config.Config) error {
+		nconf, ok := c.Options().Struct.(*cfg)
 		if !ok {
-			return fmt.Errorf("failed to get Struct from options: %v", cfg.Options())
+			return fmt.Errorf("failed to get Struct from options: %v", c.Options())
 		}
-		conf.StringValue = "after_load"
+		nconf.StringValue = "after_load"
 		return nil
 	}
 
@@ -47,6 +100,37 @@ func TestDefault(t *testing.T) {
 	if conf.StringValue != "after_load" {
 		t.Fatal("AfterLoad option not working")
 	}
+	if len(conf.MapValue) != 2 {
+		t.Fatalf("map value invalid: %#+v\n", conf.MapValue)
+	}
 
-	t.Logf("%#+v\n", conf)
+	if conf.UUIDValue == "" {
+		t.Fatalf("uuid value empty")
+	} else if len(conf.UUIDValue) != 36 {
+		t.Fatalf("uuid value invalid: %s", conf.UUIDValue)
+	}
+
+	if conf.IDValue == "" {
+		t.Fatalf("id value empty")
+	} else if len(conf.IDValue) != mid.DefaultSize {
+		t.Fatalf("id value invalid: %s", conf.IDValue)
+	}
+	_ = conf
+	// t.Logf("%#+v\n", conf)
+}
+
+func TestValidate(t *testing.T) {
+	ctx := context.Background()
+	conf := &cfg{IntValue: 10}
+	cfg := config.NewConfig(config.Struct(conf))
+	if err := cfg.Init(); err != nil {
+		t.Fatal(err)
+	}
+	if err := cfg.Load(ctx); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := config.Validate(ctx, conf); err != nil {
+		t.Fatal(err)
+	}
 }

config/options.go

@@ -2,35 +2,53 @@ package config
 
 import (
 	"context"
+	"time"
 
-	"github.com/unistack-org/micro/v3/codec"
-	"github.com/unistack-org/micro/v3/logger"
-	"github.com/unistack-org/micro/v3/meter"
-	"github.com/unistack-org/micro/v3/tracer"
+	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v3/options"
+	"go.unistack.org/micro/v3/tracer"
 )
 
 // Options hold the config options
 type Options struct {
-	Name       string
-	AllowFail  bool
-	BeforeLoad []func(context.Context, Config) error
-	AfterLoad  []func(context.Context, Config) error
-	BeforeSave []func(context.Context, Config) error
-	AfterSave  []func(context.Context, Config) error
-	// Struct that holds config data
+	// Struct holds the destination config struct
 	Struct interface{}
-	// StructTag name
-	StructTag string
-	// Logger that will be used
-	Logger logger.Logger
-	// Meter that will be used
-	Meter meter.Meter
-	// Tracer used for trace
-	Tracer tracer.Tracer
 	// Codec that used for load/save
 	Codec codec.Codec
-	// Context for alternative data
+	// Tracer that will be used
+	Tracer tracer.Tracer
+	// Meter that will be used
+	Meter meter.Meter
+	// Logger that will be used
+	Logger logger.Logger
+	// Context used for external options
 	Context context.Context
+	// Name of the config
+	Name string
+	// StructTag name
+	StructTag string
+	// BeforeSave contains slice of funcs that runs before Save
+	BeforeSave []func(context.Context, Config) error
+	// AfterSave contains slice of funcs that runs after Save
+	AfterSave []func(context.Context, Config) error
+	// BeforeLoad contains slice of funcs that runs before Load
+	BeforeLoad []func(context.Context, Config) error
+	// AfterLoad contains slice of funcs that runs after Load
+	AfterLoad []func(context.Context, Config) error
+	// BeforeInit contains slice of funcs that runs before Init
+	BeforeInit []func(context.Context, Config) error
+	// AfterInit contains slice of funcs that runs after Init
+	AfterInit []func(context.Context, Config) error
+	// AllowFail flag to allow fail in config source
+	AllowFail bool
+	// SkipLoad runs only if condition returns true
+	SkipLoad func(context.Context, Config) bool
+	// SkipSave runs only if condition returns true
+	SkipSave func(context.Context, Config) bool
+	// Hooks can be run before/after config Save/Load
+	Hooks options.Hooks
 }
 
 // Option function signature
@@ -51,6 +69,72 @@ func NewOptions(opts ...Option) Options {
 	return options
 }
 
+// LoadOption function signature
+type LoadOption func(o *LoadOptions)
+
+// LoadOptions struct
+type LoadOptions struct {
+	Struct   interface{}
+	Context  context.Context
+	Override bool
+	Append   bool
+}
+
+// NewLoadOptions create LoadOptions struct with provided opts
+func NewLoadOptions(opts ...LoadOption) LoadOptions {
+	options := LoadOptions{}
+	for _, o := range opts {
+		o(&options)
+	}
+	return options
+}
+
+// LoadOverride override values when load
+func LoadOverride(b bool) LoadOption {
+	return func(o *LoadOptions) {
+		o.Override = b
+	}
+}
+
+// LoadAppend override values when load
+func LoadAppend(b bool) LoadOption {
+	return func(o *LoadOptions) {
+		o.Append = b
+	}
+}
+
+// LoadStruct override struct for loading
+func LoadStruct(src interface{}) LoadOption {
+	return func(o *LoadOptions) {
+		o.Struct = src
+	}
+}
+
+// SaveOption function signature
+type SaveOption func(o *SaveOptions)
+
+// SaveOptions struct
+type SaveOptions struct {
+	Struct  interface{}
+	Context context.Context
+}
+
+// SaveStruct override struct for save to config
+func SaveStruct(src interface{}) SaveOption {
+	return func(o *SaveOptions) {
+		o.Struct = src
+	}
+}
+
+// NewSaveOptions fill SaveOptions struct
+func NewSaveOptions(opts ...SaveOption) SaveOptions {
+	options := SaveOptions{}
+	for _, o := range opts {
+		o(&options)
+	}
+	return options
+}
+
 // AllowFail allows config source to fail
 func AllowFail(b bool) Option {
 	return func(o *Options) {
@@ -58,6 +142,20 @@ func AllowFail(b bool) Option {
 	}
 }
 
+// BeforeInit run funcs before config Init
+func BeforeInit(fn ...func(context.Context, Config) error) Option {
+	return func(o *Options) {
+		o.BeforeInit = fn
+	}
+}
+
+// AfterInit run funcs after config Init
+func AfterInit(fn ...func(context.Context, Config) error) Option {
+	return func(o *Options) {
+		o.AfterInit = fn
+	}
+}
+
 // BeforeLoad run funcs before config load
 func BeforeLoad(fn ...func(context.Context, Config) error) Option {
 	return func(o *Options) {
@@ -134,3 +232,69 @@ func Name(n string) Option {
 		o.Name = n
 	}
 }
+
+// WatchOptions struuct
+type WatchOptions struct {
+	// Context used by non default options
+	Context context.Context
+	// Struct for filling
+	Struct interface{}
+	// MinInterval specifies the min time.Duration interval for poll changes
+	MinInterval time.Duration
+	// MaxInterval specifies the max time.Duration interval for poll changes
+	MaxInterval time.Duration
+	// Coalesce multiple events to one
+	Coalesce bool
+}
+
+// WatchOption func signature
+type WatchOption func(*WatchOptions)
+
+// NewWatchOptions create WatchOptions struct with provided opts
+func NewWatchOptions(opts ...WatchOption) WatchOptions {
+	options := WatchOptions{
+		Context:     context.Background(),
+		MinInterval: DefaultWatcherMinInterval,
+		MaxInterval: DefaultWatcherMaxInterval,
+	}
+	for _, o := range opts {
+		o(&options)
+	}
+	return options
+}
+
+// WatchContext pass context
+func WatchContext(ctx context.Context) WatchOption {
+	return func(o *WatchOptions) {
+		o.Context = ctx
+	}
+}
+
+// WatchCoalesce controls watch event combining
+func WatchCoalesce(b bool) WatchOption {
+	return func(o *WatchOptions) {
+		o.Coalesce = b
+	}
+}
+
+// WatchInterval specifies min and max time.Duration for pulling changes
+func WatchInterval(min, max time.Duration) WatchOption {
+	return func(o *WatchOptions) {
+		o.MinInterval = min
+		o.MaxInterval = max
+	}
+}
+
+// WatchStruct overrides struct for fill
+func WatchStruct(src interface{}) WatchOption {
+	return func(o *WatchOptions) {
+		o.Struct = src
+	}
+}
+
+// Hooks sets hook runs before action
+func Hooks(h ...options.Hook) Option {
+	return func(o *Options) {
+		o.Hooks = append(o.Hooks, h...)
+	}
+}

config/reflect_test.go

@@ -1,26 +0,0 @@
-package config_test
-
-import (
-	"testing"
-
-	rutil "github.com/unistack-org/micro/v3/util/reflect"
-)
-
-type Config struct {
-	Value     string
-	SubConfig *SubConfig
-	Config    *Config
-}
-
-type SubConfig struct {
-	Value string
-}
-
-func TestReflect(t *testing.T) {
-	cfg1 := &Config{Value: "cfg1", Config: &Config{Value: "cfg1_1"}, SubConfig: &SubConfig{Value: "cfg1"}}
-	cfg2, err := rutil.Zero(cfg1)
-	if err != nil {
-		t.Fatal(err)
-	}
-	t.Logf("dst: %#+v\n", cfg2)
-}

context_test.go

@@ -0,0 +1,24 @@
+package micro
+
+import (
+	"context"
+	"testing"
+)
+
+func TestFromContext(t *testing.T) {
+	ctx := context.WithValue(context.TODO(), serviceKey{}, NewService())
+
+	c, ok := FromContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("FromContext not works")
+	}
+}
+
+func TestNewContext(t *testing.T) {
+	ctx := NewContext(context.TODO(), NewService())
+
+	c, ok := FromContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("NewContext not works")
+	}
+}

database/dsn.go

@@ -0,0 +1,157 @@
+package database
+
+import (
+	"crypto/tls"
+	"errors"
+	"fmt"
+	"net/url"
+	"strings"
+)
+
+var (
+	ErrInvalidDSNAddr      = errors.New("invalid dsn addr")
+	ErrInvalidDSNUnescaped = errors.New("dsn must be escaped")
+	ErrInvalidDSNNoSlash   = errors.New("dsn must contains slash")
+)
+
+type Config struct {
+	TLSConfig *tls.Config
+	Username  string
+	Password  string
+	Scheme    string
+	Host      string
+	Port      string
+	Database  string
+	Params    []string
+}
+
+func (cfg *Config) FormatDSN() string {
+	var s strings.Builder
+
+	if len(cfg.Scheme) > 0 {
+		s.WriteString(cfg.Scheme + "://")
+	}
+	// [username[:password]@]
+	if len(cfg.Username) > 0 {
+		s.WriteString(cfg.Username)
+		if len(cfg.Password) > 0 {
+			s.WriteByte(':')
+			s.WriteString(url.PathEscape(cfg.Password))
+		}
+		s.WriteByte('@')
+	}
+
+	// [host:port]
+	if len(cfg.Host) > 0 {
+		s.WriteString(cfg.Host)
+		if len(cfg.Port) > 0 {
+			s.WriteByte(':')
+			s.WriteString(cfg.Port)
+		}
+	}
+
+	// /dbname
+	s.WriteByte('/')
+	s.WriteString(url.PathEscape(cfg.Database))
+
+	for i := 0; i < len(cfg.Params); i += 2 {
+		if i == 0 {
+			s.WriteString("?")
+		} else {
+			s.WriteString("&")
+		}
+		s.WriteString(cfg.Params[i])
+		s.WriteString("=")
+		s.WriteString(cfg.Params[i+1])
+	}
+
+	return s.String()
+}
+
+func ParseDSN(dsn string) (*Config, error) {
+	cfg := &Config{}
+
+	// [user[:password]@][net[(addr)]]/dbname[?param1=value1&paramN=valueN]
+	// Find last '/' that goes before dbname
+	foundSlash := false
+	for i := len(dsn) - 1; i >= 0; i-- {
+		if dsn[i] == '/' {
+			foundSlash = true
+			var j, k int
+
+			// left part is empty if i <= 0
+			if i > 0 {
+				// Find the first ':' in dsn
+				for j = i; j >= 0; j-- {
+					if dsn[j] == ':' {
+						cfg.Scheme = dsn[0:j]
+					}
+				}
+
+				// [username[:password]@][host]
+				// Find the last '@' in dsn[:i]
+				for j = i; j >= 0; j-- {
+					if dsn[j] == '@' {
+						// username[:password]
+						// Find the second ':' in dsn[:j]
+						for k = 0; k < j; k++ {
+							if dsn[k] == ':' {
+								if cfg.Scheme == dsn[:k] {
+									continue
+								}
+								var err error
+								cfg.Password, err = url.PathUnescape(dsn[k+1 : j])
+								if err != nil {
+									return nil, err
+								}
+								break
+							}
+						}
+						cfg.Username = dsn[len(cfg.Scheme)+3 : k]
+						break
+					}
+				}
+
+				for k = j + 1; k < i; k++ {
+					if dsn[k] == ':' {
+						cfg.Host = dsn[j+1 : k]
+						cfg.Port = dsn[k+1 : i]
+						break
+					}
+				}
+
+			}
+
+			// dbname[?param1=value1&...&paramN=valueN]
+			// Find the first '?' in dsn[i+1:]
+			for j = i + 1; j < len(dsn); j++ {
+				if dsn[j] == '?' {
+					parts := strings.Split(dsn[j+1:], "&")
+					cfg.Params = make([]string, 0, len(parts)*2)
+					for _, p := range parts {
+						k, v, found := strings.Cut(p, "=")
+						if !found {
+							continue
+						}
+						cfg.Params = append(cfg.Params, k, v)
+					}
+
+					break
+				}
+			}
+			var err error
+			dbname := dsn[i+1 : j]
+			if cfg.Database, err = url.PathUnescape(dbname); err != nil {
+				return nil, fmt.Errorf("invalid dbname %q: %w", dbname, err)
+			}
+
+			break
+		}
+	}
+
+	if !foundSlash && len(dsn) > 0 {
+		return nil, ErrInvalidDSNNoSlash
+	}
+
+	return cfg, nil
+}

database/dsn_test.go

@@ -0,0 +1,31 @@
+package database
+
+import (
+	"net/url"
+	"testing"
+)
+
+func TestParseDSN(t *testing.T) {
+	cfg, err := ParseDSN("postgres://username:p@ssword#@host:12345/dbname?key1=val2&key2=val2")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if cfg.Password != "p@ssword#" {
+		t.Fatalf("parsing error")
+	}
+}
+
+func TestFormatDSN(t *testing.T) {
+	src := "postgres://username:p@ssword#@host:12345/dbname?key1=val2&key2=val2"
+	cfg, err := ParseDSN(src)
+	if err != nil {
+		t.Fatal(err)
+	}
+	dst, err := url.PathUnescape(cfg.FormatDSN())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if src != dst {
+		t.Fatalf("\n%s\n%s", src, dst)
+	}
+}

errors/errors.go

@@ -1,11 +1,20 @@
 // Package errors provides a way to return detailed information
 // for an RPC request error. The error is normally JSON encoded.
-package errors
+package errors // import "go.unistack.org/micro/v3/errors"
 
 import (
+	"bytes"
+	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
+	"io"
 	"net/http"
+	"strconv"
+	"strings"
+
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
 )
 
 var (
@@ -37,10 +46,14 @@ var (
 
 // Error type
 type Error struct {
-	Id     string
-	Code   int32
+	// ID holds error id or service, usually someting like my_service or id
+	ID string
+	// Detail holds some useful details about error
 	Detail string
+	// Status usually holds text of http status
 	Status string
+	// Code holds error code
+	Code int32
 }
 
 // Error satisfies error interface
@@ -49,10 +62,26 @@ func (e *Error) Error() string {
 	return string(b)
 }
 
-// New generates a custom error.
+/*
+// Generator struct holds id of error
+type Generator struct {
+	id string
+}
+
+// Generator can emit new error with static id
+func NewGenerator(id string) *Generator {
+	return &Generator{id: id}
+}
+
+func (g *Generator) BadRequest(format string, args ...interface{}) error {
+	return BadRequest(g.id, format, args...)
+}
+*/
+
+// New generates a custom error
 func New(id, detail string, code int32) error {
 	return &Error{
-		Id:     id,
+		ID:     id,
 		Code:   code,
 		Detail: detail,
 		Status: http.StatusText(int(code)),
@@ -62,130 +91,130 @@ func New(id, detail string, code int32) error {
 // Parse tries to parse a JSON string into an error. If that
 // fails, it will set the given string as the error detail.
 func Parse(err string) *Error {
-	e := new(Error)
-	errr := json.Unmarshal([]byte(err), e)
-	if errr != nil {
+	e := &Error{}
+	nerr := json.Unmarshal([]byte(err), e)
+	if nerr != nil {
 		e.Detail = err
 	}
 	return e
 }
 
 // BadRequest generates a 400 error.
-func BadRequest(id, format string, a ...interface{}) error {
+func BadRequest(id, format string, args ...interface{}) error {
 	return &Error{
-		Id:     id,
+		ID:     id,
 		Code:   400,
-		Detail: fmt.Sprintf(format, a...),
+		Detail: fmt.Sprintf(format, args...),
 		Status: http.StatusText(400),
 	}
 }
 
 // Unauthorized generates a 401 error.
-func Unauthorized(id, format string, a ...interface{}) error {
+func Unauthorized(id, format string, args ...interface{}) error {
 	return &Error{
-		Id:     id,
+		ID:     id,
 		Code:   401,
-		Detail: fmt.Sprintf(format, a...),
+		Detail: fmt.Sprintf(format, args...),
 		Status: http.StatusText(401),
 	}
 }
 
 // Forbidden generates a 403 error.
-func Forbidden(id, format string, a ...interface{}) error {
+func Forbidden(id, format string, args ...interface{}) error {
 	return &Error{
-		Id:     id,
+		ID:     id,
 		Code:   403,
-		Detail: fmt.Sprintf(format, a...),
+		Detail: fmt.Sprintf(format, args...),
 		Status: http.StatusText(403),
 	}
 }
 
 // NotFound generates a 404 error.
-func NotFound(id, format string, a ...interface{}) error {
+func NotFound(id, format string, args ...interface{}) error {
 	return &Error{
-		Id:     id,
+		ID:     id,
 		Code:   404,
-		Detail: fmt.Sprintf(format, a...),
+		Detail: fmt.Sprintf(format, args...),
 		Status: http.StatusText(404),
 	}
 }
 
 // MethodNotAllowed generates a 405 error.
-func MethodNotAllowed(id, format string, a ...interface{}) error {
+func MethodNotAllowed(id, format string, args ...interface{}) error {
 	return &Error{
-		Id:     id,
+		ID:     id,
 		Code:   405,
-		Detail: fmt.Sprintf(format, a...),
+		Detail: fmt.Sprintf(format, args...),
 		Status: http.StatusText(405),
 	}
 }
 
 // Timeout generates a 408 error.
-func Timeout(id, format string, a ...interface{}) error {
+func Timeout(id, format string, args ...interface{}) error {
 	return &Error{
-		Id:     id,
+		ID:     id,
 		Code:   408,
-		Detail: fmt.Sprintf(format, a...),
+		Detail: fmt.Sprintf(format, args...),
 		Status: http.StatusText(408),
 	}
 }
 
 // Conflict generates a 409 error.
-func Conflict(id, format string, a ...interface{}) error {
+func Conflict(id, format string, args ...interface{}) error {
 	return &Error{
-		Id:     id,
+		ID:     id,
 		Code:   409,
-		Detail: fmt.Sprintf(format, a...),
+		Detail: fmt.Sprintf(format, args...),
 		Status: http.StatusText(409),
 	}
 }
 
 // InternalServerError generates a 500 error.
-func InternalServerError(id, format string, a ...interface{}) error {
+func InternalServerError(id, format string, args ...interface{}) error {
 	return &Error{
-		Id:     id,
+		ID:     id,
 		Code:   500,
-		Detail: fmt.Sprintf(format, a...),
+		Detail: fmt.Sprintf(format, args...),
 		Status: http.StatusText(500),
 	}
 }
 
 // NotImplemented generates a 501 error
-func NotImplemented(id, format string, a ...interface{}) error {
+func NotImplemented(id, format string, args ...interface{}) error {
 	return &Error{
-		Id:     id,
+		ID:     id,
 		Code:   501,
-		Detail: fmt.Sprintf(format, a...),
+		Detail: fmt.Sprintf(format, args...),
 		Status: http.StatusText(501),
 	}
 }
 
 // BadGateway generates a 502 error
-func BadGateway(id, format string, a ...interface{}) error {
+func BadGateway(id, format string, args ...interface{}) error {
 	return &Error{
-		Id:     id,
+		ID:     id,
 		Code:   502,
-		Detail: fmt.Sprintf(format, a...),
+		Detail: fmt.Sprintf(format, args...),
 		Status: http.StatusText(502),
 	}
 }
 
 // ServiceUnavailable generates a 503 error
-func ServiceUnavailable(id, format string, a ...interface{}) error {
+func ServiceUnavailable(id, format string, args ...interface{}) error {
 	return &Error{
-		Id:     id,
+		ID:     id,
 		Code:   503,
-		Detail: fmt.Sprintf(format, a...),
+		Detail: fmt.Sprintf(format, args...),
 		Status: http.StatusText(503),
 	}
 }
 
 // GatewayTimeout generates a 504 error
-func GatewayTimeout(id, format string, a ...interface{}) error {
+func GatewayTimeout(id, format string, args ...interface{}) error {
 	return &Error{
-		Id:     id,
+		ID:     id,
 		Code:   504,
-		Detail: fmt.Sprintf(format, a...),
+		Detail: fmt.Sprintf(format, args...),
 		Status: http.StatusText(504),
 	}
 }
@@ -210,11 +239,246 @@ func Equal(err1 error, err2 error) bool {
 	return true
 }
 
+// CodeIn return true if err has specified code
+func CodeIn(err interface{}, codes ...int32) bool {
+	var code int32
+	switch verr := err.(type) {
+	case *Error:
+		code = verr.Code
+	case int32:
+		code = verr
+	default:
+		return false
+	}
+
+	for _, check := range codes {
+		if code == check {
+			return true
+		}
+	}
+
+	return false
+}
+
 // FromError try to convert go error to *Error
 func FromError(err error) *Error {
+	if err == nil {
+		return nil
+	}
+
 	if verr, ok := err.(*Error); ok && verr != nil {
 		return verr
 	}
 
 	return Parse(err.Error())
 }
+
+// MarshalJSON returns error data
+func (e *Error) MarshalJSON() ([]byte, error) {
+	return e.Marshal()
+}
+
+// UnmarshalJSON set error data
+func (e *Error) UnmarshalJSON(data []byte) error {
+	return e.Unmarshal(data)
+}
+
+// ProtoMessage noop func
+func (e *Error) ProtoMessage() {}
+
+// Reset resets error
+func (e *Error) Reset() {
+	*e = Error{}
+}
+
+// String returns error as string
+func (e *Error) String() string {
+	return fmt.Sprintf(`{"id":"%s","detail":"%s","status":"%s","code":%d}`, addslashes(e.ID), addslashes(e.Detail), addslashes(e.Status), e.Code)
+}
+
+// Marshal returns error data
+func (e *Error) Marshal() ([]byte, error) {
+	return []byte(e.String()), nil
+}
+
+// Unmarshal set error data
+func (e *Error) Unmarshal(data []byte) error {
+	str := string(data)
+	if len(data) < 41 {
+		return fmt.Errorf("invalid data")
+	}
+	parts := strings.FieldsFunc(str[1:len(str)-1], func(r rune) bool {
+		return r == ','
+	})
+	for _, part := range parts {
+		nparts := strings.FieldsFunc(part, func(r rune) bool {
+			return r == ':'
+		})
+		for idx := 0; idx < len(nparts)/2; idx += 2 {
+			val := strings.Trim(nparts[idx+1], `"`)
+			if len(val) == 0 {
+				continue
+			}
+			switch {
+			case nparts[idx] == `"id"`:
+				e.ID = val
+			case nparts[idx] == `"detail"`:
+				e.Detail = val
+			case nparts[idx] == `"status"`:
+				e.Status = val
+			case nparts[idx] == `"code"`:
+				c, err := strconv.ParseInt(val, 10, 32)
+				if err != nil {
+					return err
+				}
+				e.Code = int32(c)
+			}
+			idx++
+		}
+	}
+	return nil
+}
+
+func addslashes(str string) string {
+	var buf bytes.Buffer
+	for _, char := range str {
+		switch char {
+		case '\'', '"', '\\':
+			buf.WriteRune('\\')
+		}
+		buf.WriteRune(char)
+	}
+	return buf.String()
+}
+
+type retryableError struct {
+	err error
+}
+
+// Retryable returns error that can be retried later
+func Retryable(err error) error {
+	return &retryableError{err: err}
+}
+
+type IsRetryableFunc func(error) bool
+
+var (
+	RetrayableOracleErrors = []IsRetryableFunc{
+		func(err error) bool {
+			errmsg := err.Error()
+			switch {
+			case strings.Contains(errmsg, `ORA-`):
+				return true
+			case strings.Contains(errmsg, `can not assign`):
+				return true
+			case strings.Contains(errmsg, `can't assign`):
+				return true
+			}
+			return false
+		},
+	}
+	RetrayablePostgresErrors = []IsRetryableFunc{
+		func(err error) bool {
+			errmsg := err.Error()
+			switch {
+			case strings.Contains(errmsg, `number of field descriptions must equal number of`):
+				return true
+			case strings.Contains(errmsg, `not a pointer`):
+				return true
+			case strings.Contains(errmsg, `values, but dst struct has only`):
+				return true
+			case strings.Contains(errmsg, `struct doesn't have corresponding row field`):
+				return true
+			case strings.Contains(errmsg, `cannot find field`):
+				return true
+			case strings.Contains(errmsg, `cannot scan`) || strings.Contains(errmsg, `cannot convert`):
+				return true
+			case strings.Contains(errmsg, `failed to connect to`):
+				return true
+			}
+			return false
+		},
+	}
+	RetryableMicroErrors = []IsRetryableFunc{
+		func(err error) bool {
+			switch verr := err.(type) {
+			case *Error:
+				switch verr.Code {
+				case 401, 403, 408, 500, 501, 502, 503, 504:
+					return true
+				default:
+					return false
+				}
+			case *retryableError:
+				return true
+			}
+			return false
+		},
+	}
+	RetryableGoErrors = []IsRetryableFunc{
+		func(err error) bool {
+			switch verr := err.(type) {
+			case interface{ SafeToRetry() bool }:
+				return verr.SafeToRetry()
+			case interface{ Timeout() bool }:
+				return verr.Timeout()
+			}
+			switch {
+			case errors.Is(err, io.EOF), errors.Is(err, io.ErrUnexpectedEOF):
+				return true
+			case errors.Is(err, context.DeadlineExceeded):
+				return true
+			case errors.Is(err, io.ErrClosedPipe), errors.Is(err, io.ErrShortBuffer), errors.Is(err, io.ErrShortWrite):
+				return true
+			}
+			return false
+		},
+	}
+	RetryableGrpcErrors = []IsRetryableFunc{
+		func(err error) bool {
+			st, ok := status.FromError(err)
+			if !ok {
+				return false
+			}
+			switch st.Code() {
+			case codes.Unavailable, codes.ResourceExhausted:
+				return true
+			case codes.DeadlineExceeded:
+				return true
+			case codes.Internal:
+				switch {
+				case strings.Contains(st.Message(), `transport: received the unexpected content-type "text/html; charset=UTF-8"`):
+					return true
+				case strings.Contains(st.Message(), io.ErrUnexpectedEOF.Error()):
+					return true
+				case strings.Contains(st.Message(), `stream terminated by RST_STREAM with error code: INTERNAL_ERROR`):
+					return true
+				}
+			}
+			return false
+		},
+	}
+)
+
+// Unwrap provides error wrapping
+func (e *retryableError) Unwrap() error {
+	return e.err
+}
+
+// Error returns the error string
+func (e *retryableError) Error() string {
+	if e.err == nil {
+		return ""
+	}
+	return e.err.Error()
+}
+
+// IsRetryable checks error for ability to retry later
+func IsRetryable(err error, fns ...IsRetryableFunc) bool {
+	for _, fn := range fns {
+		if ok := fn(err); ok {
+			return true
+		}
+	}
+	return false
+}

errors/errors.proto

@@ -0,0 +1,31 @@
+// Copyright 2021 Unistack LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+syntax = "proto3";
+
+package micro.errors;
+
+option cc_enable_arenas = true;
+option go_package = "go.unistack.org/micro/v3/errors;errors";
+option java_multiple_files = true;
+option java_outer_classname = "MicroErrors";
+option java_package = "micro.errors";
+option objc_class_prefix = "MERRORS";
+
+message Error {
+  string id = 1;
+  string detail = 2;
+  string status = 3;
+  uint32 code = 4;
+}

errors/errors_test.go

@@ -1,23 +1,52 @@
 package errors
 
 import (
+	"encoding/json"
 	er "errors"
+	"fmt"
 	"net/http"
 	"testing"
 )
 
+func TestIsRetrayable(t *testing.T) {
+	err := fmt.Errorf("ORA-")
+	if !IsRetryable(err, RetrayableOracleErrors...) {
+		t.Fatalf("IsRetrayable not works")
+	}
+}
+
+func TestMarshalJSON(t *testing.T) {
+	e := InternalServerError("id", "err: %v", fmt.Errorf("err: %v", `xxx: "UNIX_TIMESTAMP": invalid identifier`))
+	_, err := json.Marshal(e)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestEmpty(t *testing.T) {
+	msg := "test"
+	var err *Error
+	err = FromError(fmt.Errorf(msg))
+	if err.Detail != msg {
+		t.Fatalf("invalid error %v", err)
+	}
+	err = FromError(fmt.Errorf(`{"id":"","detail":"%s","status":"%s","code":0}`, msg, msg))
+	if err.Detail != msg || err.Status != msg {
+		t.Fatalf("invalid error %#+v", err)
+	}
+}
+
 func TestFromError(t *testing.T) {
 	err := NotFound("go.micro.test", "%s", "example")
 	merr := FromError(err)
-	if merr.Id != "go.micro.test" || merr.Code != 404 {
+	if merr.ID != "go.micro.test" || merr.Code != 404 {
 		t.Fatalf("invalid conversation %v != %v", err, merr)
 	}
 	err = er.New(err.Error())
 	merr = FromError(err)
-	if merr.Id != "go.micro.test" || merr.Code != 404 {
+	if merr.ID != "go.micro.test" || merr.Code != 404 {
 		t.Fatalf("invalid conversation %v != %v", err, merr)
 	}
-
 }
 
 func TestEqual(t *testing.T) {
@@ -32,13 +61,12 @@ func TestEqual(t *testing.T) {
 	if Equal(err1, err3) {
 		t.Fatal("errors must be not equal")
 	}
-
 }
 
 func TestErrors(t *testing.T) {
 	testData := []*Error{
 		{
-			Id:     "test",
+			ID:     "test",
 			Code:   500,
 			Detail: "Internal server error",
 			Status: http.StatusText(500),
@@ -46,7 +74,7 @@ func TestErrors(t *testing.T) {
 	}
 
 	for _, e := range testData {
-		ne := New(e.Id, e.Detail, e.Code)
+		ne := New(e.ID, e.Detail, e.Code)
 
 		if e.Error() != ne.Error() {
 			t.Fatalf("Expected %s got %s", e.Error(), ne.Error())
@@ -58,8 +86,8 @@ func TestErrors(t *testing.T) {
 			t.Fatalf("Expected error got nil %v", pe)
 		}
 
-		if pe.Id != e.Id {
-			t.Fatalf("Expected %s got %s", e.Id, pe.Id)
+		if pe.ID != e.ID {
+			t.Fatalf("Expected %s got %s", e.ID, pe.ID)
 		}
 
 		if pe.Detail != e.Detail {
@@ -75,3 +103,19 @@ func TestErrors(t *testing.T) {
 		}
 	}
 }
+
+func TestCodeIn(t *testing.T) {
+	err := InternalServerError("id", "%s", "msg")
+
+	if ok := CodeIn(err, 400, 500); !ok {
+		t.Fatalf("CodeIn not works: %v", err)
+	}
+
+	if ok := CodeIn(err.(*Error).Code, 500); !ok {
+		t.Fatalf("CodeIn not works: %v", err)
+	}
+
+	if ok := CodeIn(err, 100); ok {
+		t.Fatalf("CodeIn not works: %v", err)
+	}
+}

event.go

@@ -3,7 +3,7 @@ package micro
 import (
 	"context"
 
-	"github.com/unistack-org/micro/v3/client"
+	"go.unistack.org/micro/v3/client"
 )
 
 // Event is used to publish messages to a topic

flow/context.go

@@ -0,0 +1,34 @@
+package flow
+
+import (
+	"context"
+)
+
+type flowKey struct{}
+
+// FromContext returns Flow from context
+func FromContext(ctx context.Context) (Flow, bool) {
+	if ctx == nil {
+		return nil, false
+	}
+	c, ok := ctx.Value(flowKey{}).(Flow)
+	return c, ok
+}
+
+// NewContext stores Flow to context
+func NewContext(ctx context.Context, f Flow) context.Context {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	return context.WithValue(ctx, flowKey{}, f)
+}
+
+// SetOption returns a function to setup a context with given value
+func SetOption(k, v interface{}) Option {
+	return func(o *Options) {
+		if o.Context == nil {
+			o.Context = context.Background()
+		}
+		o.Context = context.WithValue(o.Context, k, v)
+	}
+}

flow/context_test.go

@@ -0,0 +1,53 @@
+package flow
+
+import (
+	"context"
+	"testing"
+)
+
+func TestFromNilContext(t *testing.T) {
+	// nolint: staticcheck
+	c, ok := FromContext(nil)
+	if ok || c != nil {
+		t.Fatal("FromContext not works")
+	}
+}
+
+func TestNewNilContext(t *testing.T) {
+	// nolint: staticcheck
+	ctx := NewContext(nil, NewFlow())
+
+	c, ok := FromContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("NewContext not works")
+	}
+}
+
+func TestFromContext(t *testing.T) {
+	ctx := context.WithValue(context.TODO(), flowKey{}, NewFlow())
+
+	c, ok := FromContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("FromContext not works")
+	}
+}
+
+func TestNewContext(t *testing.T) {
+	ctx := NewContext(context.TODO(), NewFlow())
+
+	c, ok := FromContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("NewContext not works")
+	}
+}
+
+func TestSetOption(t *testing.T) {
+	type key struct{}
+	o := SetOption(key{}, "test")
+	opts := &Options{}
+	o(opts)
+
+	if v, ok := opts.Context.Value(key{}).(string); !ok || v == "" {
+		t.Fatal("SetOption not works")
+	}
+}

flow/dag_test.go

@@ -7,6 +7,56 @@ import (
 	"github.com/silas/dag"
 )
 
+func TestDeps(t *testing.T) {
+	t.Skip()
+	d := &dag.AcyclicGraph{}
+
+	v0 := d.Add(&node{"v0"})
+	v1 := d.Add(&node{"v1"})
+	v2 := d.Add(&node{"v2"})
+	v3 := d.Add(&node{"v3"})
+	v4 := d.Add(&node{"v4"})
+
+	d.Connect(dag.BasicEdge(v0, v1))
+	d.Connect(dag.BasicEdge(v1, v2))
+	d.Connect(dag.BasicEdge(v2, v4))
+	d.Connect(dag.BasicEdge(v0, v3))
+	d.Connect(dag.BasicEdge(v3, v4))
+
+	if err := d.Validate(); err != nil {
+		t.Fatal(err)
+	}
+
+	d.TransitiveReduction()
+
+	var steps [][]string
+	fn := func(n dag.Vertex, idx int) error {
+		if idx == 0 {
+			steps = make([][]string, 1)
+			steps[0] = make([]string, 0, 1)
+		} else if idx >= len(steps) {
+			tsteps := make([][]string, idx+1)
+			copy(tsteps, steps)
+			steps = tsteps
+			steps[idx] = make([]string, 0, 1)
+		}
+		steps[idx] = append(steps[idx], fmt.Sprintf("%s", n))
+		return nil
+	}
+
+	start := &node{"v0"}
+	err := d.SortedDepthFirstWalk([]dag.Vertex{start}, fn)
+	checkErr(t, err)
+
+	for idx, steps := range steps {
+		fmt.Printf("level %d steps %#+v\n", idx, steps)
+	}
+
+	if len(steps[2]) != 1 {
+		t.Logf("invalid steps %#+v", steps[2])
+	}
+}
+
 func checkErr(t *testing.T, err error) {
 	if err != nil {
 		t.Fatal(err)
@@ -44,10 +94,10 @@ func TestDag(t *testing.T) {
 	var steps [][]string
 	fn := func(n dag.Vertex, idx int) error {
 		if idx == 0 {
-			steps = make([][]string, 1, 1)
+			steps = make([][]string, 1)
 			steps[0] = make([]string, 0, 1)
 		} else if idx >= len(steps) {
-			tsteps := make([][]string, idx+1, idx+1)
+			tsteps := make([][]string, idx+1)
 			copy(tsteps, steps)
 			steps = tsteps
 			steps[idx] = make([]string, 0, 1)

flow/default.go

@@ -0,0 +1,587 @@
+package flow
+
+import (
+	"context"
+	"fmt"
+	"sync"
+
+	"github.com/silas/dag"
+	"go.unistack.org/micro/v3/client"
+	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v3/store"
+	"go.unistack.org/micro/v3/util/id"
+)
+
+type microFlow struct {
+	opts Options
+}
+
+type microWorkflow struct {
+	opts   Options
+	g      *dag.AcyclicGraph
+	steps  map[string]Step
+	id     string
+	status Status
+	sync.RWMutex
+	init bool
+}
+
+func (w *microWorkflow) ID() string {
+	return w.id
+}
+
+func (w *microWorkflow) Steps() ([][]Step, error) {
+	return w.getSteps("", false)
+}
+
+func (w *microWorkflow) Status() Status {
+	return w.status
+}
+
+func (w *microWorkflow) AppendSteps(steps ...Step) error {
+	w.Lock()
+
+	for _, s := range steps {
+		w.steps[s.String()] = s
+		w.g.Add(s)
+	}
+
+	for _, dst := range steps {
+		for _, req := range dst.Requires() {
+			src, ok := w.steps[req]
+			if !ok {
+				return ErrStepNotExists
+			}
+			w.g.Connect(dag.BasicEdge(src, dst))
+		}
+	}
+
+	if err := w.g.Validate(); err != nil {
+		w.Unlock()
+		return err
+	}
+
+	w.g.TransitiveReduction()
+
+	w.Unlock()
+
+	return nil
+}
+
+func (w *microWorkflow) RemoveSteps(steps ...Step) error {
+	// TODO: handle case when some step requires or required by removed step
+
+	w.Lock()
+
+	for _, s := range steps {
+		delete(w.steps, s.String())
+		w.g.Remove(s)
+	}
+
+	for _, dst := range steps {
+		for _, req := range dst.Requires() {
+			src, ok := w.steps[req]
+			if !ok {
+				return ErrStepNotExists
+			}
+			w.g.Connect(dag.BasicEdge(src, dst))
+		}
+	}
+
+	if err := w.g.Validate(); err != nil {
+		w.Unlock()
+		return err
+	}
+
+	w.g.TransitiveReduction()
+
+	w.Unlock()
+
+	return nil
+}
+
+func (w *microWorkflow) getSteps(start string, reverse bool) ([][]Step, error) {
+	var steps [][]Step
+	var root dag.Vertex
+	var err error
+
+	fn := func(n dag.Vertex, idx int) error {
+		if idx == 0 {
+			steps = make([][]Step, 1)
+			steps[0] = make([]Step, 0, 1)
+		} else if idx >= len(steps) {
+			tsteps := make([][]Step, idx+1)
+			copy(tsteps, steps)
+			steps = tsteps
+			steps[idx] = make([]Step, 0, 1)
+		}
+		steps[idx] = append(steps[idx], n.(Step))
+		return nil
+	}
+
+	if start != "" {
+		var ok bool
+		w.RLock()
+		root, ok = w.steps[start]
+		w.RUnlock()
+		if !ok {
+			return nil, ErrStepNotExists
+		}
+	} else {
+		root, err = w.g.Root()
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if reverse {
+		err = w.g.SortedReverseDepthFirstWalk([]dag.Vertex{root}, fn)
+	} else {
+		err = w.g.SortedDepthFirstWalk([]dag.Vertex{root}, fn)
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	return steps, nil
+}
+
+func (w *microWorkflow) Abort(ctx context.Context, id string) error {
+	workflowStore := store.NewNamespaceStore(w.opts.Store, "workflows"+w.opts.Store.Options().Separator+id)
+	return workflowStore.Write(ctx, "status", &codec.Frame{Data: []byte(StatusAborted.String())})
+}
+
+func (w *microWorkflow) Suspend(ctx context.Context, id string) error {
+	workflowStore := store.NewNamespaceStore(w.opts.Store, "workflows"+w.opts.Store.Options().Separator+id)
+	return workflowStore.Write(ctx, "status", &codec.Frame{Data: []byte(StatusSuspend.String())})
+}
+
+func (w *microWorkflow) Resume(ctx context.Context, id string) error {
+	workflowStore := store.NewNamespaceStore(w.opts.Store, "workflows"+w.opts.Store.Options().Separator+id)
+	return workflowStore.Write(ctx, "status", &codec.Frame{Data: []byte(StatusRunning.String())})
+}
+
+func (w *microWorkflow) Execute(ctx context.Context, req *Message, opts ...ExecuteOption) (string, error) {
+	w.Lock()
+	if !w.init {
+		if err := w.g.Validate(); err != nil {
+			w.Unlock()
+			return "", err
+		}
+		w.g.TransitiveReduction()
+		w.init = true
+	}
+	w.Unlock()
+
+	eid, err := id.New()
+	if err != nil {
+		return "", err
+	}
+
+	stepStore := store.NewNamespaceStore(w.opts.Store, "steps"+w.opts.Store.Options().Separator+eid)
+	workflowStore := store.NewNamespaceStore(w.opts.Store, "workflows"+w.opts.Store.Options().Separator+eid)
+
+	options := NewExecuteOptions(opts...)
+
+	steps, err := w.getSteps(options.Start, options.Reverse)
+	if err != nil {
+		if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusPending.String())}); werr != nil {
+			w.opts.Logger.Errorf(w.opts.Context, "store error: %v", werr)
+		}
+		return "", err
+	}
+
+	var wg sync.WaitGroup
+	cherr := make(chan error, 1)
+	chstatus := make(chan Status, 1)
+
+	nctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+
+	nopts := make([]ExecuteOption, 0, len(opts)+5)
+
+	nopts = append(nopts,
+		ExecuteClient(w.opts.Client),
+		ExecuteTracer(w.opts.Tracer),
+		ExecuteLogger(w.opts.Logger),
+		ExecuteMeter(w.opts.Meter),
+	)
+	nopts = append(nopts, opts...)
+	done := make(chan struct{})
+
+	if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusRunning.String())}); werr != nil {
+		w.opts.Logger.Errorf(w.opts.Context, "store error: %v", werr)
+		return eid, werr
+	}
+	for idx := range steps {
+		for nidx := range steps[idx] {
+			cstep := steps[idx][nidx]
+			if werr := stepStore.Write(ctx, cstep.ID()+w.opts.Store.Options().Separator+"status", &codec.Frame{Data: []byte(StatusPending.String())}); werr != nil {
+				return eid, werr
+			}
+		}
+	}
+
+	go func() {
+		for idx := range steps {
+			for nidx := range steps[idx] {
+				wStatus := &codec.Frame{}
+				if werr := workflowStore.Read(w.opts.Context, "status", wStatus); werr != nil {
+					cherr <- werr
+					return
+				}
+				if status := StringStatus[string(wStatus.Data)]; status != StatusRunning {
+					chstatus <- status
+					return
+				}
+				if w.opts.Logger.V(logger.TraceLevel) {
+					w.opts.Logger.Tracef(nctx, "will be executed %v", steps[idx][nidx])
+				}
+				cstep := steps[idx][nidx]
+				// nolint: nestif
+				if len(cstep.Requires()) == 0 {
+					wg.Add(1)
+					go func(step Step) {
+						defer wg.Done()
+						if werr := stepStore.Write(ctx, step.ID()+w.opts.Store.Options().Separator+"req", req); werr != nil {
+							cherr <- werr
+							return
+						}
+						if werr := stepStore.Write(ctx, step.ID()+w.opts.Store.Options().Separator+"status", &codec.Frame{Data: []byte(StatusRunning.String())}); werr != nil {
+							cherr <- werr
+							return
+						}
+						rsp, serr := step.Execute(nctx, req, nopts...)
+						if serr != nil {
+							step.SetStatus(StatusFailure)
+							if werr := stepStore.Write(ctx, step.ID()+w.opts.Store.Options().Separator+"rsp", serr); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
+								w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
+							}
+							if werr := stepStore.Write(ctx, step.ID()+w.opts.Store.Options().Separator+"status", &codec.Frame{Data: []byte(StatusFailure.String())}); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
+								w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
+							}
+							cherr <- serr
+							return
+						}
+						if werr := stepStore.Write(ctx, step.ID()+w.opts.Store.Options().Separator+"rsp", rsp); werr != nil {
+							w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
+							cherr <- werr
+							return
+						}
+						if werr := stepStore.Write(ctx, step.ID()+w.opts.Store.Options().Separator+"status", &codec.Frame{Data: []byte(StatusSuccess.String())}); werr != nil {
+							w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
+							cherr <- werr
+							return
+						}
+					}(cstep)
+					wg.Wait()
+				} else {
+					if werr := stepStore.Write(ctx, cstep.ID()+w.opts.Store.Options().Separator+"req", req); werr != nil {
+						cherr <- werr
+						return
+					}
+					if werr := stepStore.Write(ctx, cstep.ID()+w.opts.Store.Options().Separator+"status", &codec.Frame{Data: []byte(StatusRunning.String())}); werr != nil {
+						cherr <- werr
+						return
+					}
+					rsp, serr := cstep.Execute(nctx, req, nopts...)
+					if serr != nil {
+						cstep.SetStatus(StatusFailure)
+						if werr := stepStore.Write(ctx, cstep.ID()+w.opts.Store.Options().Separator+"rsp", serr); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
+							w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
+						}
+						if werr := stepStore.Write(ctx, cstep.ID()+w.opts.Store.Options().Separator+"status", &codec.Frame{Data: []byte(StatusFailure.String())}); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
+							w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
+						}
+						cherr <- serr
+						return
+					}
+					if werr := stepStore.Write(ctx, cstep.ID()+w.opts.Store.Options().Separator+"rsp", rsp); werr != nil {
+						w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
+						cherr <- werr
+						return
+					}
+					if werr := stepStore.Write(ctx, cstep.ID()+w.opts.Store.Options().Separator+"status", &codec.Frame{Data: []byte(StatusSuccess.String())}); werr != nil {
+						cherr <- werr
+						return
+					}
+				}
+			}
+		}
+		close(done)
+	}()
+
+	if options.Async {
+		return eid, nil
+	}
+
+	logger.Tracef(ctx, "wait for finish or error")
+	select {
+	case <-nctx.Done():
+		err = nctx.Err()
+	case cerr := <-cherr:
+		err = cerr
+	case <-done:
+		close(cherr)
+	case <-chstatus:
+		close(chstatus)
+		return eid, nil
+	}
+
+	switch {
+	case nctx.Err() != nil:
+		if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusAborted.String())}); werr != nil {
+			w.opts.Logger.Errorf(w.opts.Context, "store error: %v", werr)
+		}
+	case err == nil:
+		if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusSuccess.String())}); werr != nil {
+			w.opts.Logger.Errorf(w.opts.Context, "store error: %v", werr)
+		}
+	case err != nil:
+		if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusFailure.String())}); werr != nil {
+			w.opts.Logger.Errorf(w.opts.Context, "store error: %v", werr)
+		}
+	}
+
+	return eid, err
+}
+
+// NewFlow create new flow
+func NewFlow(opts ...Option) Flow {
+	options := NewOptions(opts...)
+	return &microFlow{opts: options}
+}
+
+func (f *microFlow) Options() Options {
+	return f.opts
+}
+
+func (f *microFlow) Init(opts ...Option) error {
+	for _, o := range opts {
+		o(&f.opts)
+	}
+	if err := f.opts.Client.Init(); err != nil {
+		return err
+	}
+	if err := f.opts.Tracer.Init(); err != nil {
+		return err
+	}
+	if err := f.opts.Logger.Init(); err != nil {
+		return err
+	}
+	if err := f.opts.Meter.Init(); err != nil {
+		return err
+	}
+	if err := f.opts.Store.Init(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (f *microFlow) WorkflowList(ctx context.Context) ([]Workflow, error) {
+	return nil, nil
+}
+
+func (f *microFlow) WorkflowCreate(ctx context.Context, id string, steps ...Step) (Workflow, error) {
+	w := &microWorkflow{opts: f.opts, id: id, g: &dag.AcyclicGraph{}, steps: make(map[string]Step, len(steps))}
+
+	for _, s := range steps {
+		w.steps[s.String()] = s
+		w.g.Add(s)
+	}
+
+	for _, dst := range steps {
+		for _, req := range dst.Requires() {
+			src, ok := w.steps[req]
+			if !ok {
+				return nil, ErrStepNotExists
+			}
+			w.g.Connect(dag.BasicEdge(src, dst))
+		}
+	}
+
+	if err := w.g.Validate(); err != nil {
+		return nil, err
+	}
+	w.g.TransitiveReduction()
+
+	w.init = true
+
+	return w, nil
+}
+
+func (f *microFlow) WorkflowRemove(ctx context.Context, id string) error {
+	return nil
+}
+
+func (f *microFlow) WorkflowSave(ctx context.Context, w Workflow) error {
+	return nil
+}
+
+func (f *microFlow) WorkflowLoad(ctx context.Context, id string) (Workflow, error) {
+	return nil, nil
+}
+
+type microCallStep struct {
+	rsp     *Message
+	req     *Message
+	service string
+	method  string
+	opts    StepOptions
+	status  Status
+}
+
+func (s *microCallStep) Request() *Message {
+	return s.req
+}
+
+func (s *microCallStep) Response() *Message {
+	return s.rsp
+}
+
+func (s *microCallStep) ID() string {
+	return s.String()
+}
+
+func (s *microCallStep) Options() StepOptions {
+	return s.opts
+}
+
+func (s *microCallStep) Endpoint() string {
+	return s.method
+}
+
+func (s *microCallStep) Requires() []string {
+	return s.opts.Requires
+}
+
+func (s *microCallStep) Require(steps ...Step) error {
+	for _, step := range steps {
+		s.opts.Requires = append(s.opts.Requires, step.String())
+	}
+	return nil
+}
+
+func (s *microCallStep) String() string {
+	if s.opts.ID != "" {
+		return s.opts.ID
+	}
+	return fmt.Sprintf("%s.%s", s.service, s.method)
+}
+
+func (s *microCallStep) Name() string {
+	return s.String()
+}
+
+func (s *microCallStep) Hashcode() interface{} {
+	return s.String()
+}
+
+func (s *microCallStep) GetStatus() Status {
+	return s.status
+}
+
+func (s *microCallStep) SetStatus(status Status) {
+	s.status = status
+}
+
+func (s *microCallStep) Execute(ctx context.Context, req *Message, opts ...ExecuteOption) (*Message, error) {
+	options := NewExecuteOptions(opts...)
+	if options.Client == nil {
+		return nil, ErrMissingClient
+	}
+	rsp := &codec.Frame{}
+	copts := []client.CallOption{client.WithRetries(0)}
+	if options.Timeout > 0 {
+		copts = append(copts,
+			client.WithRequestTimeout(options.Timeout),
+			client.WithDialTimeout(options.Timeout))
+	}
+	nctx := metadata.NewOutgoingContext(ctx, req.Header)
+	err := options.Client.Call(nctx, options.Client.NewRequest(s.service, s.method, &codec.Frame{Data: req.Body}), rsp, copts...)
+	if err != nil {
+		return nil, err
+	}
+	md, _ := metadata.FromOutgoingContext(nctx)
+	return &Message{Header: md, Body: rsp.Data}, err
+}
+
+type microPublishStep struct {
+	req    *Message
+	rsp    *Message
+	topic  string
+	opts   StepOptions
+	status Status
+}
+
+func (s *microPublishStep) Request() *Message {
+	return s.req
+}
+
+func (s *microPublishStep) Response() *Message {
+	return s.rsp
+}
+
+func (s *microPublishStep) ID() string {
+	return s.String()
+}
+
+func (s *microPublishStep) Options() StepOptions {
+	return s.opts
+}
+
+func (s *microPublishStep) Endpoint() string {
+	return s.topic
+}
+
+func (s *microPublishStep) Requires() []string {
+	return s.opts.Requires
+}
+
+func (s *microPublishStep) Require(steps ...Step) error {
+	for _, step := range steps {
+		s.opts.Requires = append(s.opts.Requires, step.String())
+	}
+	return nil
+}
+
+func (s *microPublishStep) String() string {
+	if s.opts.ID != "" {
+		return s.opts.ID
+	}
+	return s.topic
+}
+
+func (s *microPublishStep) Name() string {
+	return s.String()
+}
+
+func (s *microPublishStep) Hashcode() interface{} {
+	return s.String()
+}
+
+func (s *microPublishStep) GetStatus() Status {
+	return s.status
+}
+
+func (s *microPublishStep) SetStatus(status Status) {
+	s.status = status
+}
+
+func (s *microPublishStep) Execute(ctx context.Context, req *Message, opts ...ExecuteOption) (*Message, error) {
+	return nil, nil
+}
+
+// NewCallStep create new step with client.Call
+func NewCallStep(service string, name string, method string, opts ...StepOption) Step {
+	options := NewStepOptions(opts...)
+	return &microCallStep{service: service, method: name + "." + method, opts: options}
+}
+
+// NewPublishStep create new step with client.Publish
+func NewPublishStep(topic string, opts ...StepOption) Step {
+	options := NewStepOptions(opts...)
+	return &microPublishStep{topic: topic, opts: options}
+}

flow/flow.go

@@ -1,7 +1,165 @@
-// Package flow is an interface used for saga pattern messaging
-package flow
+// Package flow is an interface used for saga pattern microservice workflow
+package flow // import "go.unistack.org/micro/v3/flow"
 
-type Step interface {
-	// Endpoint returns service_name.service_method
-	Endpoint() string
+import (
+	"context"
+	"errors"
+	"sync"
+	"sync/atomic"
+
+	"go.unistack.org/micro/v3/metadata"
+)
+
+var (
+	// ErrStepNotExists returns when step not found
+	ErrStepNotExists = errors.New("step not exists")
+	// ErrMissingClient returns when client.Client is missing
+	ErrMissingClient = errors.New("client not set")
+)
+
+// RawMessage is a raw encoded JSON value.
+// It implements Marshaler and Unmarshaler and can be used to delay decoding or precompute a encoding.
+type RawMessage []byte
+
+// MarshalJSON returns m as the JSON encoding of m.
+func (m *RawMessage) MarshalJSON() ([]byte, error) {
+	if m == nil {
+		return []byte("null"), nil
+	}
+	return *m, nil
+}
+
+// UnmarshalJSON sets *m to a copy of data.
+func (m *RawMessage) UnmarshalJSON(data []byte) error {
+	if m == nil {
+		return errors.New("RawMessage UnmarshalJSON on nil pointer")
+	}
+	*m = append((*m)[0:0], data...)
+	return nil
+}
+
+// Message used to transfer data between steps
+type Message struct {
+	Header metadata.Metadata
+	Body   RawMessage
+}
+
+// Step represents dedicated workflow step
+type Step interface {
+	// ID returns step id
+	ID() string
+	// Endpoint returns rpc endpoint service_name.service_method or broker topic
+	Endpoint() string
+	// Execute step run
+	Execute(ctx context.Context, req *Message, opts ...ExecuteOption) (*Message, error)
+	// Requires returns dependent steps
+	Requires() []string
+	// Options returns step options
+	Options() StepOptions
+	// Require add required steps
+	Require(steps ...Step) error
+	// String
+	String() string
+	// GetStatus returns step status
+	GetStatus() Status
+	// SetStatus sets the step status
+	SetStatus(Status)
+	// Request returns step request message
+	Request() *Message
+	// Response returns step response message
+	Response() *Message
+}
+
+// Status contains step current status
+type Status int
+
+func (status Status) String() string {
+	return StatusString[status]
+}
+
+const (
+	// StatusPending step waiting to start
+	StatusPending Status = iota
+	// StatusRunning step is running
+	StatusRunning
+	// StatusFailure step competed with error
+	StatusFailure
+	// StatusSuccess step completed without error
+	StatusSuccess
+	// StatusAborted step aborted while it running
+	StatusAborted
+	// StatusSuspend step suspended
+	StatusSuspend
+)
+
+var (
+	// StatusString contains map status => string
+	StatusString = map[Status]string{
+		StatusPending: "StatusPending",
+		StatusRunning: "StatusRunning",
+		StatusFailure: "StatusFailure",
+		StatusSuccess: "StatusSuccess",
+		StatusAborted: "StatusAborted",
+		StatusSuspend: "StatusSuspend",
+	}
+	// StringStatus contains map string => status
+	StringStatus = map[string]Status{
+		"StatusPending": StatusPending,
+		"StatusRunning": StatusRunning,
+		"StatusFailure": StatusFailure,
+		"StatusSuccess": StatusSuccess,
+		"StatusAborted": StatusAborted,
+		"StatusSuspend": StatusSuspend,
+	}
+)
+
+// Workflow contains all steps to execute
+type Workflow interface {
+	// ID returns id of the workflow
+	ID() string
+	// Execute workflow with args, return execution id and error
+	Execute(ctx context.Context, req *Message, opts ...ExecuteOption) (string, error)
+	// RemoveSteps remove steps from workflow
+	RemoveSteps(steps ...Step) error
+	// AppendSteps append steps to workflow
+	AppendSteps(steps ...Step) error
+	// Status returns workflow status
+	Status() Status
+	// Steps returns steps slice where parallel steps returned on the same level
+	Steps() ([][]Step, error)
+	// Suspend suspends execution
+	Suspend(ctx context.Context, id string) error
+	// Resume resumes execution
+	Resume(ctx context.Context, id string) error
+	// Abort abort execution
+	Abort(ctx context.Context, id string) error
+}
+
+// Flow the base interface to interact with workflows
+type Flow interface {
+	// Options returns options
+	Options() Options
+	// Init initialize
+	Init(...Option) error
+	// WorkflowCreate creates new workflow with specific id and steps
+	WorkflowCreate(ctx context.Context, id string, steps ...Step) (Workflow, error)
+	// WorkflowSave saves workflow
+	WorkflowSave(ctx context.Context, w Workflow) error
+	// WorkflowLoad loads workflow with specific id
+	WorkflowLoad(ctx context.Context, id string) (Workflow, error)
+	// WorkflowList lists all workflows
+	WorkflowList(ctx context.Context) ([]Workflow, error)
+}
+
+var (
+	flowMu      sync.Mutex
+	atomicSteps atomic.Value
+)
+
+// RegisterStep register own step with workflow
+func RegisterStep(step Step) {
+	flowMu.Lock()
+	steps, _ := atomicSteps.Load().([]Step)
+	atomicSteps.Store(append(steps, step))
+	flowMu.Unlock()
 }

flow/options.go

@@ -0,0 +1,247 @@
+package flow
+
+import (
+	"context"
+	"time"
+
+	"go.unistack.org/micro/v3/client"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v3/store"
+	"go.unistack.org/micro/v3/tracer"
+)
+
+// Option func
+type Option func(*Options)
+
+// Options server struct
+type Options struct {
+	// Context holds the external options and can be used for flow shutdown
+	Context context.Context
+	// Client holds the client.Client
+	Client client.Client
+	// Tracer holds the tracer
+	Tracer tracer.Tracer
+	// Logger holds the logger
+	Logger logger.Logger
+	// Meter holds the meter
+	Meter meter.Meter
+	// Store used for intermediate results
+	Store store.Store
+}
+
+// NewOptions returns new options struct with default or passed values
+func NewOptions(opts ...Option) Options {
+	options := Options{
+		Context: context.Background(),
+		Logger:  logger.DefaultLogger,
+		Meter:   meter.DefaultMeter,
+		Tracer:  tracer.DefaultTracer,
+		Client:  client.DefaultClient,
+	}
+
+	for _, o := range opts {
+		o(&options)
+	}
+
+	return options
+}
+
+// Logger sets the logger option
+func Logger(l logger.Logger) Option {
+	return func(o *Options) {
+		o.Logger = l
+	}
+}
+
+// Meter sets the meter option
+func Meter(m meter.Meter) Option {
+	return func(o *Options) {
+		o.Meter = m
+	}
+}
+
+// Client to use for sync/async communication
+func Client(c client.Client) Option {
+	return func(o *Options) {
+		o.Client = c
+	}
+}
+
+// Context specifies a context for the service.
+// Can be used to signal shutdown of the flow
+// or can be used for extra option values.
+func Context(ctx context.Context) Option {
+	return func(o *Options) {
+		o.Context = ctx
+	}
+}
+
+// Tracer mechanism for distributed tracking
+func Tracer(t tracer.Tracer) Option {
+	return func(o *Options) {
+		o.Tracer = t
+	}
+}
+
+// Store used for intermediate results
+func Store(s store.Store) Option {
+	return func(o *Options) {
+		o.Store = s
+	}
+}
+
+// WorkflowOption func signature
+type WorkflowOption func(*WorkflowOptions)
+
+// WorkflowOptions holds workflow options
+type WorkflowOptions struct {
+	Context context.Context
+	ID      string
+}
+
+// WorkflowID set workflow id
+func WorkflowID(id string) WorkflowOption {
+	return func(o *WorkflowOptions) {
+		o.ID = id
+	}
+}
+
+// ExecuteOptions holds execute options
+type ExecuteOptions struct {
+	// Client holds the client.Client
+	Client client.Client
+	// Tracer holds the tracer
+	Tracer tracer.Tracer
+	// Logger holds the logger
+	Logger logger.Logger
+	// Meter holds the meter
+	Meter meter.Meter
+	// Context can be used to abort execution or pass additional opts
+	Context context.Context
+	// Start step
+	Start string
+	// Timeout for execution
+	Timeout time.Duration
+	// Reverse execution
+	Reverse bool
+	// Async enables async execution
+	Async bool
+}
+
+// ExecuteOption func signature
+type ExecuteOption func(*ExecuteOptions)
+
+// ExecuteClient pass client.Client to ExecuteOption
+func ExecuteClient(c client.Client) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Client = c
+	}
+}
+
+// ExecuteTracer pass tracer.Tracer to ExecuteOption
+func ExecuteTracer(t tracer.Tracer) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Tracer = t
+	}
+}
+
+// ExecuteLogger pass logger.Logger to ExecuteOption
+func ExecuteLogger(l logger.Logger) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Logger = l
+	}
+}
+
+// ExecuteMeter pass meter.Meter to ExecuteOption
+func ExecuteMeter(m meter.Meter) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Meter = m
+	}
+}
+
+// ExecuteContext pass context.Context ot ExecuteOption
+func ExecuteContext(ctx context.Context) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Context = ctx
+	}
+}
+
+// ExecuteReverse says that dag must be run in reverse order
+func ExecuteReverse(b bool) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Reverse = b
+	}
+}
+
+// ExecuteTimeout pass timeout time.Duration for execution
+func ExecuteTimeout(td time.Duration) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Timeout = td
+	}
+}
+
+// ExecuteAsync says that caller does not wait for execution complete
+func ExecuteAsync(b bool) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Async = b
+	}
+}
+
+// NewExecuteOptions create new ExecuteOptions struct
+func NewExecuteOptions(opts ...ExecuteOption) ExecuteOptions {
+	options := ExecuteOptions{
+		Client:  client.DefaultClient,
+		Logger:  logger.DefaultLogger,
+		Tracer:  tracer.DefaultTracer,
+		Meter:   meter.DefaultMeter,
+		Context: context.Background(),
+	}
+	for _, o := range opts {
+		o(&options)
+	}
+	return options
+}
+
+// StepOptions holds step options
+type StepOptions struct {
+	Context  context.Context
+	Fallback string
+	ID       string
+	Requires []string
+}
+
+// StepOption func signature
+type StepOption func(*StepOptions)
+
+// NewStepOptions create new StepOptions struct
+func NewStepOptions(opts ...StepOption) StepOptions {
+	options := StepOptions{
+		Context: context.Background(),
+	}
+	for _, o := range opts {
+		o(&options)
+	}
+	return options
+}
+
+// StepID sets the step id for dag
+func StepID(id string) StepOption {
+	return func(o *StepOptions) {
+		o.ID = id
+	}
+}
+
+// StepRequires specifies required steps
+func StepRequires(steps ...string) StepOption {
+	return func(o *StepOptions) {
+		o.Requires = steps
+	}
+}
+
+// StepFallback set the step to run on error
+func StepFallback(step string) StepOption {
+	return func(o *StepOptions) {
+		o.Fallback = step
+	}
+}

fsm/default.go

@@ -0,0 +1,126 @@
+package fsm
+
+import (
+	"context"
+	"fmt"
+	"sync"
+)
+
+type state struct {
+	body interface{}
+	name string
+}
+
+var _ State = &state{}
+
+func (s *state) Name() string {
+	return s.name
+}
+
+func (s *state) Body() interface{} {
+	return s.body
+}
+
+// fsm is a finite state machine
+type fsm struct {
+	statesMap   map[string]StateFunc
+	current     string
+	statesOrder []string
+	opts        Options
+	mu          sync.Mutex
+}
+
+// NewFSM creates a new finite state machine having the specified initial state
+// with specified options
+func NewFSM(opts ...Option) *fsm {
+	return &fsm{
+		statesMap: map[string]StateFunc{},
+		opts:      NewOptions(opts...),
+	}
+}
+
+// Current returns the current state
+func (f *fsm) Current() string {
+	f.mu.Lock()
+	s := f.current
+	f.mu.Unlock()
+	return s
+}
+
+// Current returns the current state
+func (f *fsm) Reset() {
+	f.mu.Lock()
+	f.current = f.opts.Initial
+	f.mu.Unlock()
+}
+
+// State adds state to fsm
+func (f *fsm) State(state string, fn StateFunc) {
+	f.mu.Lock()
+	f.statesMap[state] = fn
+	f.statesOrder = append(f.statesOrder, state)
+	f.mu.Unlock()
+}
+
+// Start runs state machine with provided data
+func (f *fsm) Start(ctx context.Context, args interface{}, opts ...Option) (interface{}, error) {
+	var err error
+
+	f.mu.Lock()
+	options := f.opts
+
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	sopts := []StateOption{StateDryRun(options.DryRun)}
+
+	cstate := options.Initial
+	states := make(map[string]StateFunc, len(f.statesMap))
+	for k, v := range f.statesMap {
+		states[k] = v
+	}
+	f.current = cstate
+	f.mu.Unlock()
+
+	var s State
+	s = &state{name: cstate, body: args}
+	nstate := s.Name()
+
+	for {
+		select {
+		case <-ctx.Done():
+			return nil, ctx.Err()
+		default:
+			fn, ok := states[nstate]
+			if !ok {
+				return nil, fmt.Errorf(`state "%s" %w`, nstate, ErrInvalidState)
+			}
+			f.mu.Lock()
+			f.current = nstate
+			f.mu.Unlock()
+
+			// wrap the handler func
+			for i := len(options.Wrappers); i > 0; i-- {
+				fn = options.Wrappers[i-1](fn)
+			}
+
+			s, err = fn(ctx, s, sopts...)
+
+			switch {
+			case err != nil:
+				return s.Body(), err
+			case s.Name() == StateEnd:
+				return s.Body(), nil
+			case s.Name() == "":
+				for idx := range f.statesOrder {
+					if f.statesOrder[idx] == nstate && len(f.statesOrder) > idx+1 {
+						nstate = f.statesOrder[idx+1]
+					}
+				}
+			default:
+				nstate = s.Name()
+			}
+		}
+	}
+}

fsm/fsm.go

@@ -0,0 +1,29 @@
+package fsm // import "go.unistack.org/micro/v3/fsm"
+
+import (
+	"context"
+	"errors"
+)
+
+var (
+	ErrInvalidState = errors.New("does not exists")
+	StateEnd        = "end"
+)
+
+type State interface {
+	Name() string
+	Body() interface{}
+}
+
+// StateWrapper wraps the StateFunc and returns the equivalent
+type StateWrapper func(StateFunc) StateFunc
+
+// StateFunc called on state transition and return next step and error
+type StateFunc func(ctx context.Context, state State, opts ...StateOption) (State, error)
+
+type FSM interface {
+	Start(context.Context, interface{}, ...Option) (interface{}, error)
+	Current() string
+	Reset()
+	State(string, StateFunc)
+}

fsm/fsm_test.go

@@ -0,0 +1,72 @@
+package fsm
+
+import (
+	"context"
+	"fmt"
+	"testing"
+
+	"go.unistack.org/micro/v3/logger"
+)
+
+func TestFSMStart(t *testing.T) {
+	ctx := context.TODO()
+
+	if err := logger.DefaultLogger.Init(); err != nil {
+		t.Fatal(err)
+	}
+
+	wrapper := func(next StateFunc) StateFunc {
+		return func(sctx context.Context, s State, opts ...StateOption) (State, error) {
+			sctx = logger.NewContext(sctx, logger.Fields("state", s.Name()))
+			return next(sctx, s, opts...)
+		}
+	}
+
+	f := NewFSM(InitialState("1"), WrapState(wrapper))
+	f1 := func(sctx context.Context, s State, opts ...StateOption) (State, error) {
+		_, ok := logger.FromContext(sctx)
+		if !ok {
+			t.Fatal("f1 context does not have logger")
+		}
+		args := s.Body().(map[string]interface{})
+		if v, ok := args["request"].(string); !ok || v == "" {
+			return nil, fmt.Errorf("empty request")
+		}
+		return &state{name: "", body: map[string]interface{}{"response": "state1"}}, nil
+	}
+	f2 := func(sctx context.Context, s State, opts ...StateOption) (State, error) {
+		_, ok := logger.FromContext(sctx)
+		if !ok {
+			t.Fatal("f2 context does not have logger")
+		}
+		args := s.Body().(map[string]interface{})
+		if v, ok := args["response"].(string); !ok || v == "" {
+			return nil, fmt.Errorf("empty response")
+		}
+		return &state{name: "", body: map[string]interface{}{"response": "state2"}}, nil
+	}
+	f3 := func(sctx context.Context, s State, opts ...StateOption) (State, error) {
+		_, ok := logger.FromContext(sctx)
+		if !ok {
+			t.Fatal("f3 context does not have logger")
+		}
+		args := s.Body().(map[string]interface{})
+		if v, ok := args["response"].(string); !ok || v == "" {
+			return nil, fmt.Errorf("empty response")
+		}
+		return &state{name: StateEnd, body: map[string]interface{}{"response": "state3"}}, nil
+	}
+	f.State("1", f1)
+	f.State("2", f2)
+	f.State("3", f3)
+	rsp, err := f.Start(ctx, map[string]interface{}{"request": "state"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	args := rsp.(map[string]interface{})
+	if v, ok := args["response"].(string); !ok || v == "" {
+		t.Fatalf("nil rsp: %#+v", args)
+	} else if v != "state3" {
+		t.Fatalf("invalid rsp %#+v", args)
+	}
+}