Belajar pembangunan perkhidmatan mikro bahasa Go: daripada pemula kepada pakar

package main

import (
    "context"
    "fmt"
    "net/http"

    "github.com/go-kit/kit/endpoint"
    "github.com/go-kit/kit/log"
    "github.com/go-kit/kit/transport/http"
)

func main() {
    ctx := context.Background()
    svc := NewHelloService()

    endpoint := MakeHelloEndpoint(svc)
    handler := http.NewServer(ctx, endpoint, DecodeHelloRequest, EncodeHelloResponse)

    http.Handle("/hello", handler)
    log.Fatal(http.ListenAndServe(":8080", nil))
}

type HelloService interface {
    Hello(name string) string
}

type helloService struct{}

func (hs helloService) Hello(name string) string {
    return fmt.Sprintf("Hello, %s!", name)
}

func NewHelloService() HelloService {
    return helloService{}
}

type helloRequest struct {
    Name string `json:"name"`
}

type helloResponse struct {
    Message string `json:"message"`
}

func MakeHelloEndpoint(svc HelloService) endpoint.Endpoint {
    return func(ctx context.Context, request interface{}) (interface{}, error) {
        req := request.(helloRequest)
        msg := svc.Hello(req.Name)
        return helloResponse{Message: msg}, nil
    }
}

func DecodeHelloRequest(ctx context.Context, r *http.Request) (interface{}, error) {
    var req helloRequest
    if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
        return nil, err
    }
    return req, nil
}

func EncodeHelloResponse(ctx context.Context, w http.ResponseWriter, response interface{}) error {
    return json.NewEncoder(w).Encode(response)
}

package main

import (
    "context"
    "fmt"
    "net/http"
    "os"
    "os/signal"
    "syscall"
    "time"

    "github.com/go-kit/kit/log"

    "github.com/hashicorp/consul/api"
    "github.com/olivere/elastic/v7"
    "github.com/olivere/elastic/v7/config"
)

func main() {
    logger := log.NewLogfmtLogger(os.Stderr)

    // 创建Consul客户端
    consulConfig := api.DefaultConfig()
    consulClient, err := api.NewClient(consulConfig)
    if err != nil {
        logger.Log("err", err)
        os.Exit(1)
    }

    // 创建Elasticsearch客户端
    elasticConfig, _ := config.ParseENV()
    elasticClient, err := elastic.NewClientFromConfig(elasticConfig)
    if err != nil {
        logger.Log("err", err)
        os.Exit(1)
    }

    // 注册服务到Consul
    err = registerService(consulClient, "my-service", "http://localhost:8080")
    if err != nil {
        logger.Log("err", err)
        os.Exit(1)
    }

    // 创建HTTP服务
    svc := &Service{
        Logger:        logger,
        ConsulClient:  consulClient,
        ElasticClient: elasticClient,
    }

    mux := http.NewServeMux()
    mux.HandleFunc("/search", svc.SearchHandler)

    server := http.Server{
        Addr:    ":8080",
        Handler: mux,
    }

    go func() {
        logger.Log("msg", "server started")
        server.ListenAndServe()
    }()

    // 等待信号
    ch := make(chan os.Signal, 1)
    signal.Notify(ch, syscall.SIGINT, syscall.SIGTERM)
    <-ch

    // 注销服务
    err = deregisterService(consulClient, "my-service")
    if err != nil {
        logger.Log("err", err)
        os.Exit(1)
    }

    // 关闭HTTP服务
    ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
    defer cancel()
    server.Shutdown(ctx)
    logger.Log("msg", "server stopped")
}

// 注册服务到Consul
func registerService(consulClient *api.Client, serviceName, serviceAddr string) error {
    registration := new(api.AgentServiceRegistration)
    registration.ID = serviceName
    registration.Name = serviceName
    registration.Address = serviceAddr
    registration.Port = 8080

    check := new(api.AgentServiceCheck)
    check.HTTP = fmt.Sprintf("http://%s/health", serviceAddr)
    check.Interval = "10s"
    check.Timeout = "1s"
    check.DeregisterCriticalServiceAfter = "1m"

    registration.Check = check

    return consulClient.Agent().ServiceRegister(registration)
}

// 注销服务
func deregisterService(consulClient *api.Client, serviceName string) error {
    return consulClient.Agent().ServiceDeregister(serviceName)
}

type Service struct {
    Logger        log.Logger
    ConsulClient  *api.Client
    ElasticClient *elastic.Client
}

func (svc *Service) SearchHandler(w http.ResponseWriter, r *http.Request) {
    // 实现具体的搜索逻辑
}