From 913a076c526a84dadf161f090f20d9ca705568c2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thorben=20G=C3=BCnther?= <admin@xenrox.net>
Date: Mon, 17 Jul 2023 16:39:16 +0200
Subject: [PATCH] Implement graceful shutdown

---
 main.go | 39 +++++++++++++++++++++++++++++++++------
 1 file changed, 33 insertions(+), 6 deletions(-)

diff --git a/main.go b/main.go
index f3ff93c..748d5eb 100644
--- a/main.go
+++ b/main.go
@@ -2,6 +2,7 @@
 package main
 
 import (
+	"context"
 	"crypto/sha512"
 	"crypto/subtle"
 	_ "embed"
@@ -11,7 +12,9 @@ import (
 	"fmt"
 	"net/http"
 	"os"
+	"os/signal"
 	"strings"
+	"syscall"
 	"time"
 
 	"git.xenrox.net/~xenrox/go-log"
@@ -411,11 +414,15 @@ func (br *bridge) basicAuthMiddleware(handler http.HandlerFunc) http.HandlerFunc
 	}
 }
 
-func (br *bridge) runCleanup() {
+func (br *bridge) runCleanup(ctx context.Context) {
 	for {
-		time.Sleep(br.cfg.Cache.CleanupInterval)
-		br.logger.Info("Pruning cache")
-		br.cache.Cleanup()
+		select {
+		case <-time.After(br.cfg.Cache.CleanupInterval):
+			br.logger.Info("Pruning cache")
+			br.cache.Cleanup()
+		case <-ctx.Done():
+			return
+		}
 	}
 }
 
@@ -442,6 +449,9 @@ func main() {
 		logger.Errorf("Failed to parse logging level: %v", err)
 	}
 
+	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
+	defer stop()
+
 	client := &httpClient{&http.Client{Timeout: time.Second * 3}}
 
 	c, err := cache.NewCache(cfg.Cache)
@@ -468,7 +478,24 @@ func main() {
 	}
 
 	if _, ok := c.(*cache.MemoryCache); ok {
-		go bridge.runCleanup()
+		go bridge.runCleanup(ctx)
+	}
+
+	go func() {
+		err = httpServer.ListenAndServe()
+		if err != nil && err != http.ErrServerClosed {
+			logger.Fatalf("Failed to start HTTP server: %v", err)
+		}
+	}()
+
+	<-ctx.Done()
+	stop()
+
+	httpShutdownContext, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+
+	err = httpServer.Shutdown(httpShutdownContext)
+	if err != nil {
+		logger.Errorf("Failed to shutdown HTTP server: %v", err)
 	}
-	logger.Fatal(httpServer.ListenAndServe())
 }