Add error handling to analysis http server"

plugins/analysis/webinterface/httpserver/plugin.go

 package httpserver
 
 import (
+	"errors"
 	"net/http"
+	"sync"
 	"time"
 
 	"github.com/iotaledger/goshimmer/packages/shutdown"
 	"github.com/iotaledger/hive.go/daemon"
-	"github.com/iotaledger/hive.go/node"
+	"github.com/iotaledger/hive.go/logger"
 	"golang.org/x/net/context"
 	"golang.org/x/net/websocket"
 )
 
 var (
+	log        *logger.Logger
 	httpServer *http.Server
 	router     *http.ServeMux
 )
 
-func Configure(plugin *node.Plugin) {
+const name = "Analysis HTTP Server"
+
+func Configure() {
+	log = logger.NewLogger(name)
+
 	router = http.NewServeMux()
 	httpServer = &http.Server{Addr: ":80", Handler: router}
 
@@ -24,12 +31,30 @@ func Configure(plugin *node.Plugin) {
 	router.HandleFunc("/", index)
 }
 
-func Run(plugin *node.Plugin) {
-	daemon.BackgroundWorker("Analysis HTTP Server", func(shutdownSignal <-chan struct{}) {
-		go httpServer.ListenAndServe()
-		<-shutdownSignal
-		ctx, cancel := context.WithTimeout(context.Background(), 0*time.Second)
-		defer cancel()
-		httpServer.Shutdown(ctx)
-	}, shutdown.ShutdownPriorityAnalysis)
+func Run() {
+	if err := daemon.BackgroundWorker(name, start, shutdown.ShutdownPriorityAnalysis); err != nil {
+		log.Errorf("Error starting as daemon: %s", err)
+	}
+}
+
+func start(shutdownSignal <-chan struct{}) {
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		log.Infof(name+" started: address=%s", httpServer.Addr)
+		if err := httpServer.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
+			log.Warnf("Error listening: %s", err)
+		}
+	}()
+	<-shutdownSignal
+	log.Info("Stopping " + name + " ...")
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+	defer cancel()
+
+	if err := httpServer.Shutdown(ctx); err != nil {
+		log.Errorf("Error closing: %s", err)
+	}
+	wg.Wait()
+	log.Info("Stopping " + name + " ... done")
 }

plugins/analysis/webinterface/plugin.go

@@ -7,10 +7,10 @@ import (
 )
 
 func Configure(plugin *node.Plugin) {
-	httpserver.Configure(plugin)
+	httpserver.Configure()
 	recordedevents.Configure(plugin)
 }
 
 func Run(plugin *node.Plugin) {
-	httpserver.Run(plugin)
+	httpserver.Run()
 }