feat(worker): support graceful shutdown (#459)

* feat(worker): support graceful shutdown

notifications workers and queue have been sent to APNs/FCM before shutdown a push notification.

send buffered channel to signal.Notify to avoid blocking

see: golang/lint#175

fixed: https://github.com/appleboy/gorush/issues/441

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

Makefile

@@ -137,7 +137,7 @@ build_linux_lambda:
 	CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -a -tags 'lambda' -ldflags '$(EXTLDFLAGS)-s -w $(LDFLAGS)' -o release/linux/lambda/$(DEPLOY_IMAGE)
 
 docker_image:
-	docker build -t $(DEPLOY_ACCOUNT)/$(DEPLOY_IMAGE) -f Dockerfile .
+	docker build -t $(DEPLOY_ACCOUNT)/$(DEPLOY_IMAGE) -f ./docker/Dockerfile.linux.amd64 .
 
 docker_release: docker_image
 

README.md

@@ -83,6 +83,7 @@ A push notification micro server using [Gin](https://github.com/gin-gonic/gin) f
 - Support install TLS certificates from [Let's Encrypt](https://letsencrypt.org/) automatically.
 - Support send notification through [RPC](https://en.wikipedia.org/wiki/Remote_procedure_call) protocol, we use [gRPC](https://grpc.io/) as default framework.
 - Support running in Docker, [Kubernetes](https://kubernetes.io/) or [AWS Lambda](https://aws.amazon.com/lambda) ([Native Support in Golang](https://aws.amazon.com/blogs/compute/announcing-go-support-for-aws-lambda/))
+- Support graceful shutdown that notifications workers and queue have are sent to APNs/FCM before a push notification service is shutdown.
 
 See the default [YAML config example](config/config.yml):
 

docker-compose.yml

@@ -0,0 +1,15 @@
+version: '3'
+
+services:
+  gorush:
+    image: appleboy/gorush
+    restart: always
+    ports:
+      - "8080:8080"
+      - "9000:9000"
+    logging:
+      options:
+        max-size: "100k"
+        max-file: "3"
+    environment:
+      - GORUSH_CORE_QUEUE_NUM=512

gorush/notification_fcm_test.go

@@ -1,8 +1,10 @@
 package gorush
 
 import (
+	"context"
 	"log"
 	"os"
+	"sync"
 	"testing"
 
 	"github.com/appleboy/go-fcm"
@@ -16,7 +18,10 @@ func init() {
 		log.Fatal(err)
 	}
 
-	InitWorkers(PushConf.Core.WorkerNum, PushConf.Core.QueueNum)
+	ctx := context.Background()
+	wg := &sync.WaitGroup{}
+	wg.Add(int(PushConf.Core.WorkerNum))
+	InitWorkers(ctx, wg, PushConf.Core.WorkerNum, PushConf.Core.QueueNum)
 
 	if err := InitAppStatus(); err != nil {
 		log.Fatal(err)

gorush/server_lambda.go

@@ -13,7 +13,7 @@ func RunHTTPServer() error {
 		return nil
 	}
 
-	LogAccess.Debug("HTTPD server is running on " + PushConf.Core.Port + " port.")
+	LogAccess.Info("HTTPD server is running on " + PushConf.Core.Port + " port.")
 
 	return gateway.ListenAndServe(PushConf.Core.Address+":"+PushConf.Core.Port, routerEngine())
 }

gorush/server_normal.go

@@ -21,7 +21,7 @@ func RunHTTPServer() (err error) {
 		Handler: routerEngine(),
 	}
 
-	LogAccess.Debug("HTTPD server is running on " + PushConf.Core.Port + " port.")
+	LogAccess.Info("HTTPD server is running on " + PushConf.Core.Port + " port.")
 	if PushConf.Core.AutoTLS.Enabled {
 		return startServer(autoTLSServer())
 	} else if PushConf.Core.SSL {

gorush/status.go

@@ -10,6 +10,7 @@ import (
 	"github.com/appleboy/gorush/storage/leveldb"
 	"github.com/appleboy/gorush/storage/memory"
 	"github.com/appleboy/gorush/storage/redis"
+
 	"github.com/gin-gonic/gin"
 	"github.com/thoas/stats"
 )
@@ -41,7 +42,7 @@ type IosStatus struct {
 
 // InitAppStatus for initialize app status
 func InitAppStatus() error {
-	LogAccess.Debug("Init App Status Engine as ", PushConf.Stat.Engine)
+	LogAccess.Info("Init App Status Engine as ", PushConf.Stat.Engine)
 	switch PushConf.Stat.Engine {
 	case "memory":
 		StatStorage = memory.New()

gorush/worker.go

@@ -7,11 +7,11 @@ import (
 )
 
 // InitWorkers for initialize all workers.
-func InitWorkers(workerNum int64, queueNum int64) {
+func InitWorkers(ctx context.Context, wg *sync.WaitGroup, workerNum int64, queueNum int64) {
-	LogAccess.Debug("worker number is ", workerNum, ", queue number is ", queueNum)
+	LogAccess.Info("worker number is ", workerNum, ", queue number is ", queueNum)
 	QueueNotification = make(chan PushNotification, queueNum)
 	for i := int64(0); i < workerNum; i++ {
-		go startWorker()
+		go startWorker(ctx, wg, i)
 	}
 }
 
@@ -33,11 +33,12 @@ func SendNotification(req PushNotification) {
 	}
 }
 
-func startWorker() {
+func startWorker(ctx context.Context, wg *sync.WaitGroup, num int64) {
-	for {
+	defer wg.Done()
-		notification := <-QueueNotification
+	for notification := range QueueNotification {
 		SendNotification(notification)
 	}
+	LogAccess.Info("closed the worker num ", num)
 }
 
 // markFailedNotification adds failure logs for all tokens in push notification

main.go

@@ -1,14 +1,18 @@
 package main
 
 import (
+	"context"
 	"flag"
 	"fmt"
 	"log"
 	"net"
 	"net/http"
 	"os"
+	"os/signal"
 	"path/filepath"
 	"strconv"
+	"sync"
+	"syscall"
 	"time"
 
 	"github.com/appleboy/gorush/config"
@@ -18,6 +22,24 @@ import (
 	"golang.org/x/sync/errgroup"
 )
 
+func withContextFunc(ctx context.Context, f func()) context.Context {
+	ctx, cancel := context.WithCancel(ctx)
+	go func() {
+		c := make(chan os.Signal, 1)
+		signal.Notify(c, syscall.SIGINT, syscall.SIGTERM)
+		defer signal.Stop(c)
+
+		select {
+		case <-ctx.Done():
+		case <-c:
+			cancel()
+			f()
+		}
+	}()
+
+	return ctx
+}
+
 func main() {
 	opts := config.ConfYaml{}
 
@@ -223,20 +245,30 @@ func main() {
 	}
 
 	if err = gorush.InitAppStatus(); err != nil {
-		return
+		gorush.LogError.Fatal(err)
 	}
 
-	gorush.InitWorkers(gorush.PushConf.Core.WorkerNum, gorush.PushConf.Core.QueueNum)
+	wg := &sync.WaitGroup{}
+	wg.Add(int(gorush.PushConf.Core.WorkerNum))
+	ctx := withContextFunc(context.Background(), func() {
+		gorush.LogAccess.Info("close the notification queue channel")
+		close(gorush.QueueNotification)
+		wg.Wait()
+		gorush.LogAccess.Info("the notification queue has been clear")
+	})
+
+	gorush.InitWorkers(ctx, wg, gorush.PushConf.Core.WorkerNum, gorush.PushConf.Core.QueueNum)
+
+	if err = gorush.InitAPNSClient(); err != nil {
+		gorush.LogError.Fatal(err)
+	}
+
+	if _, err = gorush.InitFCMClient(gorush.PushConf.Android.APIKey); err != nil {
+		gorush.LogError.Fatal(err)
+	}
 
 	var g errgroup.Group
 
-	g.Go(gorush.InitAPNSClient)
-
-	g.Go(func() error {
-		_, err := gorush.InitFCMClient(gorush.PushConf.Android.APIKey)
-		return err
-	})
-
 	g.Go(gorush.RunHTTPServer) // Run httpd server
 	g.Go(rpc.RunGRPCServer)    // Run gRPC internal server
 

rpc/server.go

@@ -100,7 +100,7 @@ func (s *Server) Send(ctx context.Context, in *proto.NotificationRequest) (*prot
 // RunGRPCServer run gorush grpc server
 func RunGRPCServer() error {
 	if !gorush.PushConf.GRPC.Enabled {
-		gorush.LogAccess.Debug("gRPC server is disabled.")
+		gorush.LogAccess.Info("gRPC server is disabled.")
 		return nil
 	}