4.2 KiB
4.2 KiB
Go Micro
Go Micro is a microservices library which provides the fundamental building blocks for writing fault tolerant distributed systems at scale. It is part of the Micro toolchain.
An example server can be found in examples/server.
Features
Feature | Package | Description |
---|---|---|
Discovery | Registry | A way of locating services to communicate with |
Client | Client | Used to make RPC requests to a service |
Server | Server | Listens and serves RPC requests |
Pub/Sub | Broker | Publish and Subscribe to events |
Transport | Transport | Communication mechanism between services |
Prerequisites
Consul is the default discovery mechanism provided in go-micro. Discovery is however pluggable.
Install Consul
https://www.consul.io/intro/getting-started/install.html
Getting Started
Run Consul
$ consul agent -server -bootstrap-expect 1 -data-dir /tmp/consul
Run Service
$ go run examples/server/main.go --logtostderr
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
I1108 11:08:19.926407 11358 rpc_server.go:233] Listening on [::]:54080
I1108 11:08:19.926500 11358 http_broker.go:80] Broker Listening on [::]:54081
I1108 11:08:19.926632 11358 rpc_server.go:158] Registering node: go.micro.srv.example-04de4cf0-8609-11e5-bf3a-68a86d0d36b6
Test Service
$ go run examples/client/main.go
go.micro.srv.example-59b6e0ab-0300-11e5-b696-68a86d0d36b6: Hello John
Writing a service
Create request/response proto
go-micro/examples/server/proto/example/example.proto
:
syntax = "proto3";
message Request {
string name = 1;
}
message Response {
string msg = 1;
}
Compile proto protoc -I$GOPATH/src --go_out=$GOPATH/src $GOPATH/src/github.com/myodc/go-micro/examples/server/proto/example/example.proto
Create request handler
go-micro/examples/server/handler/example.go
:
package handler
import (
log "github.com/golang/glog"
c "github.com/myodc/go-micro/context"
example "github.com/myodc/go-micro/examples/server/proto/example"
"github.com/myodc/go-micro/server"
"golang.org/x/net/context"
)
type Example struct{}
func (e *Example) Call(ctx context.Context, req *example.Request, rsp *example.Response) error {
md, _ := c.GetMetadata(ctx)
log.Infof("Received Example.Call request with metadata: %v", md)
rsp.Msg = server.Config().Id() + ": Hello " + req.Name
return nil
}
Init server
go-micro/examples/server/main.go
:
package main
import (
log "github.com/golang/glog"
"github.com/myodc/go-micro/cmd"
"github.com/myodc/go-micro/examples/server/handler"
"github.com/myodc/go-micro/server"
)
func main() {
// optionally setup command line usage
cmd.Init()
// Initialise Server
server.Init(
server.Name("go.micro.srv.example"),
)
// Register Handlers
server.Handle(
server.NewHandler(
new(handler.Example),
),
)
// Run server
if err := server.Run(); err != nil {
log.Fatal(err)
}
}
Run service
$ go run examples/server/main.go --logtostderr
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
I1108 11:08:19.926407 11358 rpc_server.go:233] Listening on [::]:54080
I1108 11:08:19.926500 11358 http_broker.go:80] Broker Listening on [::]:54081
I1108 11:08:19.926632 11358 rpc_server.go:158] Registering node: go.micro.srv.example-04de4cf0-8609-11e5-bf3a-68a86d0d36b6