145 lines
4.9 KiB
Markdown
145 lines
4.9 KiB
Markdown
# Go Micro [](https://godoc.org/github.com/micro/go-micro) [](https://travis-ci.org/micro/go-micro)
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Go Micro is a pluggable RPC based microservice library which provides the fundamental building blocks for writing distributed applications. It is part of the [Micro](https://github.com/micro/micro) toolchain. It supports Proto-RPC and JSON-RPC as the request/response protocol out of the box and defaults to Consul for discovery.
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Every aspect of go-micro is pluggable.
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An example server can be found in examples/server.
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- [Mailing List](https://groups.google.com/forum/#!forum/micro-services)
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- [Slack](https://micro-services.slack.com) : [auto-invite](http://micro-invites.herokuapp.com/)
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## Features
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Feature | Package | Built-in Plugin | Description
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------- | ------- | --------- | -----------
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Discovery | [Registry](https://godoc.org/github.com/micro/go-micro/registry) | consul | A way of locating services to communicate with
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Client | [Client](https://godoc.org/github.com/micro/go-micro/client) | rpc | Used to make RPC requests to a service
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Codec | [Codec](https://godoc.org/github.com/micro/go-micro/codec) | proto,json | Encoding/Decoding handler for requests
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Balancer | [Selector](https://godoc.org/github.com/micro/go-micro/selector) | random | Service node filter and pool
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Server | [Server](https://godoc.org/github.com/micro/go-micro/server) | rpc | Listens and serves RPC requests
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Pub/Sub | [Broker](https://godoc.org/github.com/micro/go-micro/broker) | http | Publish and Subscribe to events
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Transport | [Transport](https://godoc.org/github.com/micro/go-micro/transport) | http | Communication mechanism between services
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## Go Plugins
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By default go-micro only provides a single implementation of each interface. Plugins can be found at [github.com/micro/go-plugins](https://github.com/micro/go-plugins). Contributions welcome!
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## Prerequisites
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Consul is the default discovery mechanism provided in go-micro. Discovery is however pluggable.
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### Install Consul
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[https://www.consul.io/intro/getting-started/install.html](https://www.consul.io/intro/getting-started/install.html)
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## Getting Started
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### Run Consul
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```
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$ consul agent -server -bootstrap-expect 1 -data-dir /tmp/consul
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```
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### Run Service
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```
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$ go run examples/server/main.go --logtostderr
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I1108 11:08:19.926071 11358 server.go:96] Starting server go.micro.srv.example id go.micro.srv.example-04de4cf0-8609-11e5-bf3a-68a86d0d36b6
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I1108 11:08:19.926407 11358 rpc_server.go:233] Listening on [::]:54080
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I1108 11:08:19.926500 11358 http_broker.go:80] Broker Listening on [::]:54081
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I1108 11:08:19.926632 11358 rpc_server.go:158] Registering node: go.micro.srv.example-04de4cf0-8609-11e5-bf3a-68a86d0d36b6
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```
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### Test Service
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```
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$ go run examples/client/main.go
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go.micro.srv.example-59b6e0ab-0300-11e5-b696-68a86d0d36b6: Hello John
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```
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## Writing a service
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### Create request/response proto
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`go-micro/examples/server/proto/example/example.proto`:
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```
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syntax = "proto3";
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message Request {
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string name = 1;
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}
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message Response {
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string msg = 1;
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}
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```
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Compile proto `protoc -I$GOPATH/src --go_out=$GOPATH/src $GOPATH/src/github.com/micro/go-micro/examples/server/proto/example/example.proto`
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### Create request handler
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`go-micro/examples/server/handler/example.go`:
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```go
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package handler
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import (
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log "github.com/golang/glog"
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c "github.com/micro/go-micro/context"
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example "github.com/micro/go-micro/examples/server/proto/example"
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"github.com/micro/go-micro/server"
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"golang.org/x/net/context"
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)
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type Example struct{}
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func (e *Example) Call(ctx context.Context, req *example.Request, rsp *example.Response) error {
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md, _ := c.GetMetadata(ctx)
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log.Infof("Received Example.Call request with metadata: %v", md)
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rsp.Msg = server.Config().Id() + ": Hello " + req.Name
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return nil
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}
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```
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### Init server
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`go-micro/examples/server/main.go`:
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```go
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package main
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import (
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log "github.com/golang/glog"
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"github.com/micro/go-micro/cmd"
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"github.com/micro/go-micro/examples/server/handler"
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"github.com/micro/go-micro/server"
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)
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func main() {
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// optionally setup command line usage
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cmd.Init()
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// Initialise Server
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server.Init(
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server.Name("go.micro.srv.example"),
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)
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// Register Handlers
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server.Handle(
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server.NewHandler(
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new(handler.Example),
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),
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)
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// Run server
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if err := server.Run(); err != nil {
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log.Fatal(err)
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}
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}
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```
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### Run service
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```
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$ go run examples/server/main.go --logtostderr
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I1108 11:08:19.926071 11358 server.go:96] Starting server go.micro.srv.example id go.micro.srv.example-04de4cf0-8609-11e5-bf3a-68a86d0d36b6
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I1108 11:08:19.926407 11358 rpc_server.go:233] Listening on [::]:54080
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I1108 11:08:19.926500 11358 http_broker.go:80] Broker Listening on [::]:54081
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I1108 11:08:19.926632 11358 rpc_server.go:158] Registering node: go.micro.srv.example-04de4cf0-8609-11e5-bf3a-68a86d0d36b6
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```
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