Chapter10. gRPC Service - Healthcheck

HealthCheck 구현 Server

package main

import (
    "context"
    "errors"
    "fmt"
    "io"
    "log"
    "net"
    "os"
    "strings"

    svc "github.com/handson-go/chap10/server_healthcheck/service"
    "google.golang.org/grpc"
    healthz "google.golang.org/grpc/health"
    healthsvc "google.golang.org/grpc/health/grpc_health_v1"
)

type userService struct {
    svc.UnimplementedUsersServer
}

func (s *userService) GetUser(
    ctx context.Context,
    in *svc.UserGetRequest,
) (*svc.UserGetReply, error) {
    log.Printf(
        "Received request for user with Email: %s Id: %s\n",
        in.Email,
        in.Id,
    )
    components := strings.Split(in.Email, "@")
    if len(components) != 2 {
        return nil, errors.New("invalid email address")
    }
    u := svc.User{
        Id:        in.Id,
        FirstName: components[0],
        LastName:  components[1],
        Age:       36,
    }
    return &svc.UserGetReply{User: &u}, nil
}

func (s *userService) GetHelp(
    stream svc.Users_GetHelpServer,
) error {
    for {

        request, err := stream.Recv()
        if err == io.EOF {
            break
        }
        if err != nil {
            return err
        }
        fmt.Printf("Request receieved: %s\n", request.Request)
        response := svc.UserHelpReply{
            Response: request.Request,
        }
        err = stream.Send(&response)
        if err != nil {
            return err
        }
    }
    return nil
}

func registerServices(s *grpc.Server, h *healthz.Server) {
    svc.RegisterUsersServer(s, &userService{})
    healthsvc.RegisterHealthServer(s, h)
}

func updateServiceHealth(
    h *healthz.Server,
    service string,
    status healthsvc.HealthCheckResponse_ServingStatus,
) {
    h.SetServingStatus(
        service,
        status,
    )
}

func startServer(s *grpc.Server, l net.Listener) error {
    return s.Serve(l)
}

func main() {
    listenAddr := os.Getenv("LISTEN_ADDR")
    if len(listenAddr) == 0 {
        listenAddr = ":50051"
    }

    lis, err := net.Listen("tcp", listenAddr)
    if err != nil {
        log.Fatal(err)
    }
    s := grpc.NewServer()
    h := healthz.NewServer() // health 서비스 초기화, *healthz.Server 객체 반환
    registerServices(s, h)
    updateServiceHealth(
        h,
        svc.Users_ServiceDesc.ServiceName, // Users 서비스 이름
        healthsvc.HealthCheckResponse_SERVING,
    )
    log.Fatal(startServer(s, lis))
}
robert-min / handson-go

Chapter10. gRPC Service - Healthcheck #30

서버 강건성을 위한 gRPC Healthcheck 구현

HealthCheck 구현 Server
