go-micro使用etcd服务发现 示例 从零

前言

之前用的consul进行服务发现，现在转为使用etcd

开始

1 安装etcd

docker 启动etcd （单机测试版）

docker pull quay.io/coreos/etcd

编辑docker-compose.yml

version: "3"
services:
  etcd:
    image: quay.io/coreos/etcd:latest
    ports:
      - "2379:2379"
      - "4001:4001"
      - "2380:2380"
    environment:
      - ETCDCTL_API=3
    volumes:
      - "/data/etcd/dir:/data"
    command:
      /usr/local/bin/etcd
      -data-dir /data
      -name node1
      -advertise-client-urls http://0.0.0.0:2379
      -listen-client-urls http://0.0.0.0:2379
      -initial-cluster etcd0=http://0.0.0.0:2380
      -listen-peer-urls http://0.0.0.0:2380
      -initial-cluster-state new

启动

docker-compose up -d

测试 成功

curl -L http://127.0.0.1:2379/v2/members

curl -L http://127.0.0.1:2379/v2/keys/foo -XPUT -d value="Hello foo"

{"members":[{"id":"8e9e05c52164694d","name":"node1","peerURLs":["http://localhost:2380"],"clientURLs":["http://0.0.0.0:2379"]}]}

curl -L http://127.0.0.1:2379/v2/keys/foo
                      
{"action":"get","node":{"key":"/foo","value":"Hello foo","modifiedIndex":5,"createdIndex":5}}

2 go-micro 示例

hi.proto文件

syntax = "proto3";

package hello;

service Say {
    rpc Hello(SayRequest) returns (SayResponse) {}
}


message SayRequest {
    string from = 1;
    string to = 2;
    string msg = 3;
}

message SayResponse {
    string from = 1;
    string to = 2;
    string msg = 3;
}

编译

➜ tree protoc  --micro_out=. --go_out=. hi.proto

产生go文件

➜  tree
.
├── hi.micro.go
├── hi.pb.go
└── hi.proto
0 directories, 3 files

server.go 服务端示例代码

package main

import (
    "context"
    "fmt"

    "github.com/cowkeys/test/etcd/proto/hello"

    "github.com/micro/go-micro"
    "github.com/micro/go-micro/registry"
    "github.com/micro/go-plugins/registry/etcdv3"
)

type Say struct{}

func (s *Say) Hello(ctx context.Context, req *hello.SayRequest, rsp *hello.SayResponse) error {
    fmt.Printf("received req %#v \n", req)
    rsp.From = "server"
    rsp.To = "client"
    rsp.Msg = "ok"
    return nil
}

func main() {
    reg := etcdv3.NewRegistry(func(op *registry.Options) {
        op.Addrs = []string{"http://127.0.0.1:2379"}
    })

    service := micro.NewService(
        micro.Name("cowkeys.srv.say"),
        micro.Registry(reg),
    )
    service.Init()

    hello.RegisterSayHandler(service.Server(), new(Say))

    if err := service.Run(); err != nil {
        panic(err)
    }
}

运行

go run main.go

报很多错

cannot use auth.callOpts (type []"github.com/coreos/etcd/vendor/google.golang.org/grpc".CallOption) as type []"go.etcd.io/etcd/vendor/google.golang.org/grpc".CallOption in argument to auth.remote.AuthEnable

感觉是micro与etcd库路径或者版本不一致, 直接用govendor来处理包，然后
重新运行，运行成功：

➜  server go run server.go 

2019-10-16 15:26:22.869873 I | Transport [http] Listening on [::]:34129
2019-10-16 15:26:22.869916 I | Broker [http] Connected to [::]:40577
2019-10-16 15:26:22.870161 I | Registry [etcdv3] Registering node: cowkeys.srv.say-bc3deb4a-ae65-4e1c-8af8-c95fd02b376a

client 客户端调用示例代码：

package main

import (
    "context"
    "fmt"

    "github.com/cowkeys/test/etcd/proto/hello"
    "github.com/micro/go-micro"
    "github.com/micro/go-micro/registry"
    "github.com/micro/go-plugins/registry/etcdv3"
)

func main() {
    reg := etcdv3.NewRegistry(func(op *registry.Options) {
        op.Addrs = []string{
            "http://127.0.0.1:2379",
        }
    })

    service := micro.NewService(
        micro.Registry(reg),
    )
    service.Init()

    sayClent := hello.NewSayService("cowkeys.srv.say", service.Client())
    param := &hello.SayRequest{
        From: "client",
        To:   "server",
        Msg:  "hello xxx",
    }

    rsp, err := sayClent.Hello(context.Background(), param)
    if err != nil {
        panic(err)
    }

    fmt.Println(rsp)
}

运行

➜  go run client.go                                                                                                                                                 
from:"server" to:"client" msg:"ok"

// server 会打印出来调用信息
received req &hello.SayRequest{From:"client", To:"server", Msg:"hello xxx", XXX_NoUnkeyedLiteral:struct {}{}, XXX_unrecognized:[]uint8(nil), XXX_sizecache:0}

到此执行成功

其他etcd命令