consul+grpc使用

创建grpc服务

安装protobuf，然后clone一份示例代码

https://github.com/grpc/grpc-go.git

cd grpc-go/examples/helloworld/

向consul注册服务和查找服务

// greeter_server/main.go
import "github.com/hashicorp/consul/api"

func main() {
  registry, err := api.NewClient(api.DefaultConfig())

	if err != nil {
		fmt.Println("NewClient err", err)
		return
	}

	// 告诉consul，即将注册的服务的配置信息
	reg := api.AgentServiceRegistration{
		ID:      "service_id",
		Name:    "service_name",
		Tags:    []string{"shou", "consul"},
		Port:    8080,
		Address: "127.0.0.1",
		Check: &api.AgentServiceCheck{
			TCP:      "127.0.0.1:8080",
			CheckID:  "consul check id",
			Interval: "5s",  // 每5秒检测一次，超时1秒判定不健康
			Timeout:  "1s",
		},
	}
	err = registry.Agent().ServiceRegister(&reg)
	if err != nil {
		fmt.Println("service reg failed", err)
		return
	}

  // 下面就是常规的监听端口，注册grpc等操作
  lis, err := net.Listen("tcp", fmt.Sprintf(":%d", 8080))
	if err != nil {
		log.Fatalf("failed to listen: %v", err)
	}
  // ...
}

// greeter_client/main.go
func main() {

  // 这里和server一样
	registry, err := api.NewClient(api.DefaultConfig())
	if err != nil {
		fmt.Println("NewClient err", err)
		return
	}

  // 去找到一个健康的服务
	services, _, err := registry.Health().Service("sev_name", "shou", true, nil)
	if err != nil {
		fmt.Println("Health.service error", err)
		return
	}
  // 这里就取第一个，然后拼接一个地址，然后Dial的时候就不再是写死地址了
	addr := services[0].Service.Address + ":" + strconv.Itoa(services[0].Service.Port)
	// Set up a connection to the server.
	conn, err := grpc.Dial(addr, grpc.WithTransportCredentials(insecure.NewCredentials()))
	if err != nil {
		log.Fatalf("did not connect: %v", err)
	}
	defer conn.Close()
	// ...
}

验证

• 启动consul

  就用默认的配置: consul agent -dev

• 启动server和客户端

  go run greeter_client/main.go
  go run greeter_server/main.go

• 客户端的终端应该能看到 Greeting: Hello world