Add Systemd watchdog

cli/daemon.go

@@ -18,6 +18,7 @@ import (
 	"miniflux.app/service/httpd"
 	"miniflux.app/service/scheduler"
 	"miniflux.app/storage"
+	"miniflux.app/systemd"
 	"miniflux.app/worker"
 )
 
@@ -44,9 +45,35 @@ func startDaemon(store *storage.Storage) {
 		go collector.GatherStorageMetrics()
 	}
 
-	// Notify systemd that we are ready.
-	if err := sdNotify(sdNotifyReady); err != nil {
-		logger.Error("Unable to send readiness notification to systemd: %v", err)
+	if systemd.HasNotifySocket() {
+		logger.Info("Sending readiness notification to Systemd")
+
+		if err := systemd.SdNotify(systemd.SdNotifyReady); err != nil {
+			logger.Error("Unable to send readiness notification to systemd: %v", err)
+		}
+
+		if systemd.HasSystemdWatchdog() {
+			logger.Info("Activating Systemd watchdog")
+
+			go func() {
+				interval, err := systemd.WatchdogInterval()
+				if err != nil {
+					logger.Error("Unable to parse watchdog interval from systemd: %v", err)
+					return
+				}
+
+				for {
+					err := store.Ping()
+					if err != nil {
+						logger.Error(`Systemd Watchdog: %v`, err)
+					} else {
+						systemd.SdNotify(systemd.SdNotifyWatchdog)
+					}
+
+					time.Sleep(interval / 2)
+				}
+			}()
+		}
 	}
 
 	<-stop

cli/sd_notify.go

@@ -1,42 +0,0 @@
-// Copyright 2021 Frédéric Guillot. All rights reserved.
-// Use of this source code is governed by the Apache 2.0
-// license that can be found in the LICENSE file.
-
-package cli // import "miniflux.app/cli"
-
-import (
-	"net"
-	"os"
-)
-
-const (
-	// sdNotifyReady tells the service manager that service startup is
-	// finished, or the service finished loading its configuration.
-	sdNotifyReady = "READY=1"
-)
-
-// sdNotify sends a message to systemd using the sd_notify protocol.
-// See https://www.freedesktop.org/software/systemd/man/sd_notify.html.
-func sdNotify(state string) error {
-	addr := &net.UnixAddr{
-		Net:  "unixgram",
-		Name: os.Getenv("NOTIFY_SOCKET"),
-	}
-
-	if addr.Name == "" {
-		// We're not running under systemd (NOTIFY_SOCKET has not set).
-		return nil
-	}
-
-	conn, err := net.DialUnix(addr.Net, nil, addr)
-	if err != nil {
-		return err
-	}
-	defer conn.Close()
-
-	if _, err = conn.Write([]byte(state)); err != nil {
-		return err
-	}
-
-	return nil
-}