基于Grpc的健康检查

syntax = "proto3";

package grpc.health.v1;

message HealthCheckRequest {
  string service = 1;
}

message HealthCheckResponse {
  enum ServingStatus {
    UNKNOWN = 0;
    SERVING = 1;
    NOT_SERVING = 2;
    SERVICE_UNKNOWN = 3;  // Used only by the Watch method.
  }
  ServingStatus status = 1;
}

service Health {
  rpc Check(HealthCheckRequest) returns (HealthCheckResponse);

  rpc Watch(HealthCheckRequest) returns (stream HealthCheckResponse);
}

package main

import (
	"context"
	"fmt"
	"log"
)

import (
	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials/insecure"
	healthpb "google.golang.org/grpc/health/grpc_health_v1"
)

const (
	address = "localhost:20000"
)

func main() {
	// Set up a connection to the server
	conn, err := grpc.Dial(address, grpc.WithTransportCredentials(insecure.NewCredentials()))
	if err != nil {
		log.Fatalf("did not connect: %v", err)
	}

	defer func() {
		_ = conn.Close()
	}()
	
	checkHealth("org.apache.dubbogo.samples.api.Greeter", conn)
}

func checkHealth(service string, conn *grpc.ClientConn) {
	fmt.Printf(">>>>> gRPC-go check %s status", service)

	req := &healthpb.HealthCheckRequest{
		Service: service,
	}
	ctx := context.Background()
	rsp, err := healthpb.NewHealthClient(conn).Check(ctx, req)
	if err != nil {
		panic(err)
	}
	fmt.Printf("get service status = %+v\n", rsp)
}