From b099f51ae36c08e09cbf187a47419c65a7664bfc Mon Sep 17 00:00:00 2001
From: helder-junior <helder.junior@wildlifestudios.com>
Date: Thu, 21 Nov 2024 14:02:50 -0300
Subject: [PATCH] Fix server gracefull shutdown (#42)

* Fix gracefull shutdown

* Add gracefull shutdown docker compose

* Fix signal handler

* Add log after gracefull shutdown finishes
---
 docker-compose-ci.yaml |  1 +
 server/app/app.go      | 42 ++++++++++++++++++++++++++++--------------
 server/dev.Dockerfile  |  3 +--
 3 files changed, 30 insertions(+), 16 deletions(-)

diff --git a/docker-compose-ci.yaml b/docker-compose-ci.yaml
index 406f314..31253d1 100644
--- a/docker-compose-ci.yaml
+++ b/docker-compose-ci.yaml
@@ -37,6 +37,7 @@ services:
     depends_on:
       kafka:
         condition: service_healthy
+    stop_grace_period: 30s
     healthcheck:
       test: [ "CMD", "nc", "-z", "localhost", "5000" ]
       interval: 5s
diff --git a/server/app/app.go b/server/app/app.go
index 63e0981..e7b4c7a 100644
--- a/server/app/app.go
+++ b/server/app/app.go
@@ -26,6 +26,9 @@ import (
 	"context"
 	"fmt"
 	"net"
+	"os"
+	"os/signal"
+	"syscall"
 	"time"
 
 	"github.com/golang/protobuf/proto"
@@ -75,7 +78,7 @@ func NewApp(host string, port int, log logger.Logger, config *viper.Viper) (*App
 	return a, err
 }
 
-func (a *App) loadConfigurationDefaults() {
+func (a *App) configure() error {
 	a.config.SetDefault("otlp.enabled", false)
 	a.config.SetDefault("kafka.producer.net.maxOpenRequests", 10)
 	a.config.SetDefault("kafka.producer.net.dialTimeout", "500ms")
@@ -98,10 +101,6 @@ func (a *App) loadConfigurationDefaults() {
 	a.config.SetDefault("server.Timeout", "500ms")
 	a.config.SetDefault("prometheus.enabled", "true") // always true on the API side
 	a.config.SetDefault("prometheus.port", ":9091")
-}
-
-func (a *App) configure() error {
-	a.loadConfigurationDefaults()
 
 	if a.config.GetBool("otlp.enabled") {
 		if err := a.configureOTel(); err != nil {
@@ -222,12 +221,12 @@ func (a *App) metricsReporterInterceptor(
 
 // Run runs the app
 func (a *App) Run() {
-	log := a.log
+
 	listener, err := net.Listen("tcp", fmt.Sprintf("%s:%d", a.host, a.port))
 	if err != nil {
-		log.Panic(err.Error())
+		a.log.Panic(err.Error())
 	}
-	log.Infof("events gateway listening on %s:%d", a.host, a.port)
+	a.log.Infof("events gateway listening on %s:%d", a.host, a.port)
 
 	metrics.StartServer(a.config)
 	var opts []grpc.ServerOption
@@ -250,11 +249,26 @@ func (a *App) Run() {
 	a.grpcServer = grpc.NewServer(opts...)
 
 	pb.RegisterGRPCForwarderServer(a.grpcServer, a.Server)
-	if err := a.grpcServer.Serve(listener); err != nil {
-		log.Panic(err.Error())
-	}
-}
+	var stopChan = make(chan os.Signal, 2)
+
+	signal.Notify(stopChan, os.Interrupt, syscall.SIGTERM)
+	var errChan = make(chan error)
 
-func (a *App) Stop() {
-	a.grpcServer.GracefulStop()
+	go func() {
+		if err := a.grpcServer.Serve(listener); err != nil {
+			errChan <- err
+		}
+	}()
+
+	defer func() {
+		a.log.Info("Calling GRPC Gracefull stop...")
+		a.grpcServer.GracefulStop()
+		a.log.Info("Finished GRPC Gracefull stop...")
+	}()
+	select {
+	case err := <-errChan:
+		a.log.Panicf("Server failed with error: %s", err.Error())
+	case sig := <-stopChan:
+		a.log.Infof("Got signal %s from OS. Stopping...", sig)
+	}
 }
diff --git a/server/dev.Dockerfile b/server/dev.Dockerfile
index ce1cad3..c880289 100644
--- a/server/dev.Dockerfile
+++ b/server/dev.Dockerfile
@@ -7,6 +7,5 @@ ADD .. /app
 
 RUN apk add make build-base
 
-RUN go install github.com/wadey/gocovmerge@v0.0.0-20160331181800-b5bfa59ec0ad && \
-    go install github.com/onsi/ginkgo/v2/ginkgo@v2.19.1 && \
+RUN go install github.com/onsi/ginkgo/v2/ginkgo@v2.19.1 && \
     go mod tidy