3.使用consul作为服务发现.md

3.使用consul作为服务发现

安装 consul

brew install consul

本地启动

consul agent -dev

代码

consul
├── consul
│   └── main.go
├── mdns
│   └── main.go
└── proto
    ├── build.sh
    ├── greeter.micro.go
    ├── greeter.pb.go
    └── greeter.proto

mdns/main.go

consul/mdns/main.go 的代码和srv中的server/main.go几乎是一模一样的

go run consul/mdns/main.go

2019/06/23 20:05:10 Transport [http] Listening on [::]:58616
2019/06/23 20:05:10 Broker [http] Connected to [::]:58617
2019/06/23 20:05:10 Registry [mdns] Registering node: go.micro.srv.greeter-cc5d6b85-7b82-40a8-9e9a-a2c0468d6c17

可以看到 go-micro 默认使用的是 mdns 进行的服务发现

如何将服务发现切换到 consul 呢？

不修改代码

MICRO_REGISTRY=consul go run main.go
go run main.go --registry=consul

修改代码

package main

import (
	"context"
	"github.com/cheerego/go-micro-in-action/consul/proto"
	"github.com/micro/go-micro"
	"github.com/micro/go-micro/registry"
	"github.com/micro/go-micro/registry/consul"
	"log"
)

type Greeter struct{}


func (s *Greeter) Hello(ctx context.Context, req *greeter.Request, rsp *greeter.Response) error {
	log.Print("Received Say.Hello request")
	rsp.Greeting = "Hello " + req.Name
	return nil
}

func main() {
	service := micro.NewService(
		micro.Name("go.micro.srv.greeter"),
		micro.Registry(consul.NewRegistry(func(options *registry.Options) {
			options.Addrs = []string{
				"127.0.0.1:8500",
			}
		})),
	)

	// optionally setup command line usage
	service.Init()

	// Register Handlers
	greeter.RegisterGreeterHandler(service.Server(), new(Greeter))

	// Run server
	if err := service.Run(); err != nil {
		log.Fatal(err)
	}
}

micro.Registry(consul.NewRegistry(func(options *registry.Options) {
			options.Addrs = []string{
				"127.0.0.1:8500",
			}
		})),

2019/06/23 20:08:58 Transport [http] Listening on [::]:58650
2019/06/23 20:08:58 Broker [http] Connected to [::]:58651
2019/06/23 20:08:58 Registry [consul] Registering node: go.micro.srv.greeter-4e2b4996-0904-4105-8a10-f741e6b99c67