Handle graceful http shutdown

frontend/main.go

@@ -1,13 +1,16 @@
 package main
 
 import (
+	"context"
 	"flag"
 	"fmt"
 	"log"
 	"net/http"
 	"os"
+	"os/signal"
 	"path"
 	"strings"
+	"syscall"
 
 	fronttime "srs.epita.fr/fic-server/frontend/time"
 	"srs.epita.fr/fic-server/settings"
@@ -48,9 +51,24 @@ func main() {
 	http.Handle(fmt.Sprintf("%s/submission/", *prefix), http.StripPrefix(fmt.Sprintf("%s/submission/", *prefix), submissionTeamChecker{"submission", SubmissionHandler, *teamsDir}))
 	http.Handle(fmt.Sprintf("%s/time.json", *prefix), http.StripPrefix(*prefix, fronttime.TimeHandler{}))
 
-	// Serve pages
-	log.Println(fmt.Sprintf("Ready, listening on %s", *bind))
-	if err := http.ListenAndServe(*bind, nil); err != nil {
-		log.Fatal("Unable to listen and serve: ", err)
+	// Prepare graceful shutdown
+	interrupt := make(chan os.Signal, 1)
+	signal.Notify(interrupt, os.Interrupt, syscall.SIGTERM)
+
+	srv := &http.Server{
+		Addr: *bind,
 	}
+
+	// Serve pages
+	go func() {
+		log.Fatal(srv.ListenAndServe())
+	}()
+	log.Println(fmt.Sprintf("Ready, listening on %s", *bind))
+
+	// Wait shutdown signal
+	<-interrupt
+
+	log.Print("The service is shutting down...")
+	srv.Shutdown(context.Background())
+	log.Println("done")
 }