Remove pidfile when program exits (closes #495)

caddy/sigtrap.go

@@ -32,10 +32,18 @@ func trapSignalsCrossPlatform() {
 
 			if i > 0 {
 				log.Println("[INFO] SIGINT: Force quit")
+				if PidFile != "" {
+					os.Remove(PidFile)
+				}
 				os.Exit(1)
 			}
 
 			log.Println("[INFO] SIGINT: Shutting down")
+
+			if PidFile != "" {
+				os.Remove(PidFile)
+			}
+
 			go os.Exit(executeShutdownCallbacks("SIGINT"))
 		}
 	}()

caddy/sigtrap_posix.go

@@ -20,6 +20,9 @@ func trapSignalsPosix() {
 			switch sig {
 			case syscall.SIGTERM:
 				log.Println("[INFO] SIGTERM: Terminating process")
+				if PidFile != "" {
+					os.Remove(PidFile)
+				}
 				os.Exit(0)
 
 			case syscall.SIGQUIT:
@@ -30,6 +33,9 @@ func trapSignalsPosix() {
 					log.Printf("[ERROR] SIGQUIT stop: %v", err)
 					exitCode = 1
 				}
+				if PidFile != "" {
+					os.Remove(PidFile)
+				}
 				os.Exit(exitCode)
 
 			case syscall.SIGHUP: