Add environment variable to inhibit restart

cmd/syncthing/main.go

@@ -41,7 +41,11 @@ var (
 
 const (
 	usage      = "syncthing [options]"
-	extraUsage = `The following environemnt variables can be set to facilitate debugging:
+	extraUsage = `The following enviroment variables are interpreted by syncthing:
+
+ STNORESTART  Do not attempt to restart when requested to, instead just exit.
+              Set this variable when running under a service manager such as
+              runit, launchd, etc.
 
  STPROFILER   Set to a listen address such as "127.0.0.1:9090" to start the
               profiler with HTTP access.
@@ -50,7 +54,7 @@ const (
               facility strings:
               - "scanner"  (the file change scanner)
               - "discover" (the node discovery package)
-             - "net"      (connecting and disconnecting, sent/received messages)
+              - "net"      (connecting and disconnecting, network messages)
               - "idx"      (index sending and receiving)
               - "need"     (file need calculations)
               - "pull"     (file pull activity)`
@@ -299,6 +303,12 @@ func main() {
 
 func restart() {
 	infoln("Restarting")
+	if os.Getenv("SMF_FMRI") != "" || os.Getenv("STNORESTART") != "" {
+		// Solaris SMF
+		infoln("Service manager detected; exit instead of restart")
+		os.Exit(0)
+	}
+
 	env := os.Environ()
 	if len(os.Getenv("STRESTART")) == 0 {
 		env = append(env, "STRESTART=1")