[2.0] Healthcheck. Readiness

gripmock.go

@@ -2,15 +2,18 @@ package main
 
 import (
 	"bytes"
+	"context"
 	"flag"
 	"fmt"
 	"log"
+	"net"
 	"os"
 	"os/exec"
 	"os/signal"
 	"path"
 	"strings"
 	"syscall"
+	"time"
 
 	_ "github.com/bavix/gripmock/protogen"
 	"github.com/bavix/gripmock/stub"
@@ -47,8 +50,12 @@ func main() {
 		}
 	}
 
+	ctx := context.Background()
+
+	chReady := make(chan struct{})
+
 	// run admin stub server
-	stub.RunRestServer(stub.Options{
+	stub.RunRestServer(chReady, stub.Options{
 		StubPath: *stubPath,
 		Port:     *adminport,
 		BindAddr: *adminBindAddr,
@@ -76,6 +83,28 @@ func main() {
 	// and run
 	run, runerr := runGrpcServer(output)
 
+	// This is a kind of crutch, but now there is no other solution.
+	//I have an idea to combine gripmock and grpcmock services into one, then this check will be easier to do.
+	// Checking the grpc port of the service. If the port appears, the service has started successfully.
+	go func() {
+		var d net.Dialer
+
+		for {
+			dialCtx, cancel := context.WithTimeout(ctx, time.Second)
+
+			conn, err := d.DialContext(dialCtx, "tcp", net.JoinHostPort(*grpcBindAddr, *grpcPort))
+			cancel()
+
+			if err == nil && conn != nil {
+				chReady <- struct{}{}
+
+				conn.Close()
+
+				break
+			}
+		}
+	}()
+
 	term := make(chan os.Signal, 1)
 	signal.Notify(term, syscall.SIGTERM, syscall.SIGINT)
 	select {

internal/app/rest_server.go

@@ -24,6 +24,7 @@ type StubsServer struct {
 	convertor *yaml2json.Convertor
 	caser     cases.Caser
 	clock     *clock.Clock
+	ok        bool
 }
 
 func NewRestServer(path string) (*StubsServer, error) {
@@ -54,11 +55,23 @@ type findStubPayload struct {
 	Data    map[string]interface{} `json:"data"`
 }
 
+func (h *StubsServer) ServiceReady() {
+	h.ok = true
+}
+
 func (h *StubsServer) Liveness(w http.ResponseWriter, _ *http.Request) {
 	_ = json.NewEncoder(w).Encode(rest.MessageOK{Message: "ok", Time: h.clock.Now()})
 }
 
 func (h *StubsServer) Readiness(w http.ResponseWriter, _ *http.Request) {
+	if !h.ok {
+		w.WriteHeader(http.StatusServiceUnavailable)
+
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+
 	_ = json.NewEncoder(w).Encode(rest.MessageOK{Message: "ok", Time: h.clock.Now()})
 }
 

stub/stub.go

@@ -21,7 +21,7 @@ type Options struct {
 
 const DefaultPort = "4771"
 
-func RunRestServer(opt Options) {
+func RunRestServer(ch chan struct{}, opt Options) {
 	if opt.Port == "" {
 		opt.Port = DefaultPort
 	}
@@ -38,4 +38,13 @@ func RunRestServer(opt Options) {
 		err := http.ListenAndServe(addr, handler)
 		log.Fatal(err)
 	}()
+
+	go func() {
+		select {
+		case <-ch:
+			apiServer.ServiceReady()
+		}
+
+		log.Println("GRPC-service is ready to accept requests")
+	}()
 }