Zipkin : Golang 微服务全链路监控（四）

Golang 微服务全链路监控实现

  1. broker-service -> auth-service -> postgres db
  2. zipkin 监控：需代码入侵

使用 zipkin 库的 serverMiddleware，其通过 Http 跟踪（trace）链路。访问 auth-service，需通过 zipkinhttp.NewClient() 方法

zipkinhttp "github.com/openzipkin/zipkin-go/middleware/http"

一、broker-service

  1. 通过 Http 传递 span
    main.go
package mainimport ("log""net/http"zipkinhttp "github.com/openzipkin/zipkin-go/middleware/http"
)type Config struct{}const (// Our service name.serviceName = "auth"// Host + port of our service.hostPort = "localhost:8090"// Endpoint to send Zipkin spans to.zipkinHTTPEndpoint = "http://localhost:9411/api/v2/spans"
)func main() {tracer := GetTracer(serviceName, hostPort, zipkinHTTPEndpoint)// create global zipkin http server middlewareserverMiddleware := zipkinhttp.NewServerMiddleware(tracer, zipkinhttp.TagResponseSize(true),)// create global zipkin traced http clientclient, err := zipkinhttp.NewClient(tracer, zipkinhttp.ClientTrace(true))if err != nil {log.Fatalf("unable to create client: %+v\n", err)}app := Config{}router := http.NewServeMux()router.HandleFunc("/auth", app.Auth(client))if err = http.ListenAndServe(":8080", serverMiddleware(router)); err != nil {log.Panic(err)}
}
  1. 访问 auth 服务
    handler.go
package mainimport ("bytes""encoding/json""log""net/http""github.com/openzipkin/zipkin-go"zipkinhttp "github.com/openzipkin/zipkin-go/middleware/http"
)type AuthPayload struct {Email    string `json:"email"`Password string `json:"password"`
}func (app *Config) Auth(client *zipkinhttp.Client) http.HandlerFunc {return func(w http.ResponseWriter, r *http.Request) {log.Printf("auth service called with method: %s\n", r.Method)// retrieve span from context (created by server middleware)span := zipkin.SpanFromContext(r.Context())defer span.Finish()span.Tag("event", "authenticate")var requestPayload AuthPayloadvar payload jsonResponsepayload.Error = truepayload.Message = "Authentication failed!"err := app.readJSON(w, r, &requestPayload)if err != nil {app.errorJSON(w, err)return}// create json and send to the auth microservicelog.Println("authRequst: ", requestPayload)jsonData, _ := json.Marshal(requestPayload)url := "http://localhost:8090"newRequest, err := http.NewRequest("POST", url+"/authenticate", bytes.NewBuffer(jsonData))if err != nil {log.Printf("unable to create client: %+v\n", err)app.errorJSON(w, err, http.StatusBadRequest)span.Tag("Error: ", err.Error())return}newRequest.Header.Add("Content-type", "application/json")ctx := zipkin.NewContext(newRequest.Context(), span)newRequest = newRequest.WithContext(ctx)resp, err := client.DoWithAppSpan(newRequest, "auth")if err != nil {log.Printf("call to auth returned error: %+v\n", err)app.errorJSON(w, err, http.StatusBadGateway)span.Tag("Error: ", err.Error())return}defer resp.Body.Close()err = json.NewDecoder(resp.Body).Decode(&payload)if err != nil {app.errorJSON(w, err, http.StatusBadGateway)span.Tag("Error: ", err.Error())return}app.writeJSON(w, http.StatusAccepted, payload)}
}

二、说明

完整代码参考：

  1. Zipkin : Golang 微服务全链路监控（一）
  2. Zipkin : Golang 微服务全链路监控（二）