Add -restart=inproc flag for in process restart

caddy/caddy.go

@@ -52,6 +52,11 @@ var (
 
 	// GracefulTimeout is the maximum duration of a graceful shutdown.
 	GracefulTimeout time.Duration
+
+	// RestartMode is the mode used for restart,
+	// "inproc" will restart in process,
+	// otherwise default behavior is used (inproc on Windows, fork on Linux).
+	RestartMode = ""
 )
 
 var (

caddy/restart.go

@@ -25,6 +25,10 @@ func init() {
 // downtime if on a POSIX-compatible system, or forcefully if on
 // Windows but with imperceptibly-short downtime.
 //
+// The behavior can be controlled by the RestartMode variable,
+// where "inproc" will restart forcefully in process same as
+// Windows on a POSIX-compatible system.
+//
 // The restarted application will use newCaddyfile as its input
 // configuration. If newCaddyfile is nil, the current (existing)
 // Caddyfile configuration will be used.
@@ -48,6 +52,10 @@ func Restart(newCaddyfile Input) error {
 		return errors.New("TLS preload: " + err.Error())
 	}
 
+	if RestartMode == "inproc" {
+		return restartInProc(newCaddyfile)
+	}
+
 	if len(os.Args) == 0 { // this should never happen, but...
 		os.Args = []string{""}
 	}
@@ -164,3 +172,22 @@ func getCertsForNewCaddyfile(newCaddyfile Input) error {
 
 	return nil
 }
+
+// restartInProc restarts Caddy forcefully in process using newCaddyfile.
+func restartInProc(newCaddyfile Input) error {
+	wg.Add(1) // barrier so Wait() doesn't unblock
+
+	err := Stop()
+	if err != nil {
+		return err
+	}
+
+	err = Start(newCaddyfile)
+	if err != nil {
+		return err
+	}
+
+	wg.Done() // take down our barrier
+
+	return nil
+}

main.go

@@ -33,6 +33,7 @@ func init() {
 	flag.StringVar(&caddy.PidFile, "pidfile", "", "Path to write pid file")
 	flag.StringVar(&caddy.Port, "port", caddy.DefaultPort, "Default port")
 	flag.BoolVar(&caddy.Quiet, "quiet", false, "Quiet mode (no initialization output)")
+	flag.StringVar(&caddy.RestartMode, "restart", "", "Restart mode (inproc for in process restart)")
 	flag.StringVar(&revoke, "revoke", "", "Hostname for which to revoke the certificate")
 	flag.StringVar(&caddy.Root, "root", caddy.DefaultRoot, "Root path to default site")
 	flag.BoolVar(&version, "version", false, "Show version")