server: add garbage collector and graceful shutdown

Author: x1unix

cmd/playground/main.go

@@ -1,28 +1,42 @@
 package main
 
 import (
+	"context"
 	"flag"
 	"fmt"
+	"net/http"
+	"os"
+	"sync"
+	"time"
+
 	"github.com/gorilla/mux"
+	"github.com/x1unix/foundation/app"
 	"github.com/x1unix/go-playground/pkg/analyzer"
 	"github.com/x1unix/go-playground/pkg/compiler"
 	"github.com/x1unix/go-playground/pkg/compiler/storage"
 	"github.com/x1unix/go-playground/pkg/langserver"
 	"go.uber.org/zap"
-	"log"
-	"net/http"
-	"os"
 )
 
+type appArgs struct {
+	packagesFile    string
+	addr            string
+	debug           bool
+	buildDir        string
+	cleanupInterval string
+}
+
+func (a appArgs) getCleanDuration() (time.Duration, error) {
+	return time.ParseDuration(a.cleanupInterval)
+}
+
 func main() {
-	var packagesFile string
-	var addr string
-	var debug bool
-	var buildDir string
-	flag.StringVar(&packagesFile, "f", "packages.json", "Path to packages index JSON file")
-	flag.StringVar(&addr, "addr", ":8080", "TCP Listen address")
-	flag.StringVar(&buildDir, "wasm-build-dir", os.TempDir(), "Directory for WASM builds")
-	flag.BoolVar(&debug, "debug", false, "Enable debug mode")
+	args := appArgs{}
+	flag.StringVar(&args.packagesFile, "f", "packages.json", "Path to packages index JSON file")
+	flag.StringVar(&args.addr, "addr", ":8080", "TCP Listen address")
+	flag.StringVar(&args.buildDir, "wasm-build-dir", os.TempDir(), "Directory for WASM builds")
+	flag.StringVar(&args.cleanupInterval, "clean-interval", "10m", "Build directory cleanup interval")
+	flag.BoolVar(&args.debug, "debug", false, "Enable debug mode")
 
 	goRoot, ok := os.LookupEnv("GOROOT")
 	if !ok {
@@ -31,9 +45,9 @@ func main() {
 	}
 
 	flag.Parse()
-	l := getLogger(debug)
+	l := getLogger(args.debug)
 	defer l.Sync()
-	if err := start(packagesFile, addr, goRoot, buildDir, debug); err != nil {
+	if err := start(goRoot, args); err != nil {
 		l.Sugar().Fatal(err)
 	}
 }
@@ -55,37 +69,78 @@ func getLogger(debug bool) (l *zap.Logger) {
 	return l
 }
 
-func start(packagesFile, addr, goRoot, buildDir string, debug bool) error {
+func start(goRoot string, args appArgs) error {
+	cleanInterval, err := args.getCleanDuration()
+	if err != nil {
+		return fmt.Errorf("invalid cleanup interval parameter: %s", err)
+	}
+
 	zap.S().Infof("GOROOT is %q", goRoot)
-	zap.S().Infof("Packages file is %q", packagesFile)
+	zap.S().Infof("Packages file is %q", args.packagesFile)
+	zap.S().Infof("Cleanup interval is %s", cleanInterval.String())
 	analyzer.SetRoot(goRoot)
-	packages, err := analyzer.ReadPackagesFile(packagesFile)
+	packages, err := analyzer.ReadPackagesFile(args.packagesFile)
 	if err != nil {
-		return fmt.Errorf("failed to read packages file %q: %s", packagesFile, err)
+		return fmt.Errorf("failed to read packages file %q: %s", args.packagesFile, err)
 	}
 
-	store, err := storage.NewLocalStorage(zap.S(), buildDir)
+	store, err := storage.NewLocalStorage(zap.S(), args.buildDir)
 	if err != nil {
 		return err
 	}
 
+	ctx, _ := app.GetApplicationContext()
+	wg := &sync.WaitGroup{}
+	go store.StartCleaner(ctx, cleanInterval, wg)
+
 	r := mux.NewRouter()
 	langserver.New(packages, compiler.NewBuildService(zap.S(), store)).
 		Mount(r.PathPrefix("/api").Subrouter())
 	r.PathPrefix("/").Handler(langserver.SpaFileServer("./public"))
 
-	zap.S().Infof("Listening on %q", addr)
-
 	var handler http.Handler
-	if debug {
+	if args.debug {
 		zap.S().Info("Debug mode enabled, CORS disabled")
 		handler = langserver.NewCORSDisablerWrapper(r)
 	} else {
 		handler = r
 	}
 
-	if err := http.ListenAndServe(addr, handler); err != nil {
-		log.Fatal(err)
+	server := &http.Server{
+		Addr:         args.addr,
+		Handler:      handler,
+		ReadTimeout:  5 * time.Second,
+		WriteTimeout: 10 * time.Second,
+		IdleTimeout:  15 * time.Second,
+	}
+
+	if err := startHttpServer(ctx, wg, server); err != nil {
+		return err
+	}
+
+	wg.Wait()
+	return nil
+}
+
+func startHttpServer(ctx context.Context, wg *sync.WaitGroup, server *http.Server) error {
+	logger := zap.S()
+	go func() {
+		<-ctx.Done()
+		logger.Info("Shutting down server...")
+		shutdownCtx, cancel := context.WithTimeout(ctx, 30*time.Second)
+		defer cancel()
+		defer wg.Done()
+		server.SetKeepAlivesEnabled(false)
+		if err := server.Shutdown(shutdownCtx); err != nil {
+			logger.Errorf("Could not gracefully shutdown the server: %v\n", err)
+		}
+		return
+	}()
+
+	wg.Add(1)
+	logger.Infof("Listening on %q", server.Addr)
+	if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+		return fmt.Errorf("cannot start server on %q: %s", server.Addr, err)
 	}
 
 	return nil

go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/pkg/errors v0.8.1
 	github.com/stretchr/testify v1.4.0
 	github.com/tevino/abool v0.0.0-20170917061928-9b9efcf221b5
+	github.com/x1unix/foundation v1.0.0
 	go.uber.org/atomic v1.5.1 // indirect
 	go.uber.org/multierr v1.4.0 // indirect
 	go.uber.org/zap v1.13.0

go.sum

@@ -23,6 +23,8 @@ github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJy
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/tevino/abool v0.0.0-20170917061928-9b9efcf221b5 h1:hNna6Fi0eP1f2sMBe/rJicDmaHmoXGe1Ta84FPYHLuE=
 github.com/tevino/abool v0.0.0-20170917061928-9b9efcf221b5/go.mod h1:f1SCnEOt6sc3fOJfPQDRDzHOtSXuTtnz0ImG9kPRDV0=
+github.com/x1unix/foundation v1.0.0 h1:tG0dG1sbiF9TGrjwns+wtX5feBprRD5iTvpmgQDnacA=
+github.com/x1unix/foundation v1.0.0/go.mod h1:y9E4igeUWi+njm4xCM48NItLhVH/Jj1KGE069I3J5Hc=
 go.uber.org/atomic v1.5.0 h1:OI5t8sDa1Or+q8AeE+yKeB/SDYioSHAgcVljj9JIETY=
 go.uber.org/atomic v1.5.0/go.mod h1:sABNBOSYdrvTF6hTgEIbc7YasKWGhgEQZyfxyTvoXHQ=
 go.uber.org/atomic v1.5.1 h1:rsqfU5vBkVknbhUGbAUwQKR2H4ItV8tjJ+6kJX4cxHM=

pkg/compiler/storage/local.go

@@ -164,14 +164,17 @@ func (s LocalStorage) clean() error {
 	return nil
 }
 
-func (s LocalStorage) StartCleaner(ctx context.Context, interval time.Duration) {
+func (s LocalStorage) StartCleaner(ctx context.Context, interval time.Duration, wg *sync.WaitGroup) {
 	s.gcRun.Set()
 	s.log.Debug("cleaner worker starter")
 	for {
 		select {
 		case <-ctx.Done():
 			s.log.Debug("context done, cleaner worker stopped")
 			s.gcRun.UnSet()
+			if wg != nil {
+				wg.Done()
+			}
 			return
 		default:
 		}