From 5f9634b1f6ac337db8ba8cc09e0b7866749eba5e Mon Sep 17 00:00:00 2001
From: John Howard <jhoward@microsoft.com>
Date: Wed, 8 Mar 2017 15:18:30 -0800
Subject: [PATCH] Windows: no pidfile when service

Signed-off-by: John Howard <jhoward@microsoft.com>
Upstream-commit: a8e144dab4ec12eb5111df26abc87f7939faa1c3
Component: engine
---
 components/engine/cmd/dockerd/docker.go       |  7 ++++++-
 .../engine/cmd/dockerd/service_unsupported.go |  4 ++--
 .../engine/cmd/dockerd/service_windows.go     | 21 +++++++++++--------
 3 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/components/engine/cmd/dockerd/docker.go b/components/engine/cmd/dockerd/docker.go
index 6d1674f147..0bde86d203 100644
--- a/components/engine/cmd/dockerd/docker.go
+++ b/components/engine/cmd/dockerd/docker.go
@@ -74,7 +74,7 @@ func runDaemon(opts daemonOptions) error {
 
 	// On Windows, this may be launching as a service or with an option to
 	// register the service.
-	stop, err := initService(daemonCli)
+	stop, runAsService, err := initService(daemonCli)
 	if err != nil {
 		logrus.Fatal(err)
 	}
@@ -83,6 +83,11 @@ func runDaemon(opts daemonOptions) error {
 		return nil
 	}
 
+	// If Windows SCM manages the service - no need for PID files
+	if runAsService {
+		opts.daemonConfig.Pidfile = ""
+	}
+
 	err = daemonCli.start(opts)
 	notifyShutdown(err)
 	return err
diff --git a/components/engine/cmd/dockerd/service_unsupported.go b/components/engine/cmd/dockerd/service_unsupported.go
index 64ad7fcaa0..e67ad474b1 100644
--- a/components/engine/cmd/dockerd/service_unsupported.go
+++ b/components/engine/cmd/dockerd/service_unsupported.go
@@ -6,8 +6,8 @@ import (
 	"github.com/spf13/pflag"
 )
 
-func initService(daemonCli *DaemonCli) (bool, error) {
-	return false, nil
+func initService(daemonCli *DaemonCli) (bool, bool, error) {
+	return false, false, nil
 }
 
 func installServiceFlags(flags *pflag.FlagSet) {
diff --git a/components/engine/cmd/dockerd/service_windows.go b/components/engine/cmd/dockerd/service_windows.go
index 10171b0e3e..3d038fad79 100644
--- a/components/engine/cmd/dockerd/service_windows.go
+++ b/components/engine/cmd/dockerd/service_windows.go
@@ -254,25 +254,28 @@ func unregisterService() error {
 	return nil
 }
 
-func initService(daemonCli *DaemonCli) (bool, error) {
+// initService is the entry point for running the daemon as a Windows
+// service. It returns an indication to stop (if registering/un-registering);
+// an indication of whether it is running as a service; and an error.
+func initService(daemonCli *DaemonCli) (bool, bool, error) {
 	if *flUnregisterService {
 		if *flRegisterService {
-			return true, errors.New("--register-service and --unregister-service cannot be used together")
+			return true, false, errors.New("--register-service and --unregister-service cannot be used together")
 		}
-		return true, unregisterService()
+		return true, false, unregisterService()
 	}
 
 	if *flRegisterService {
-		return true, registerService()
+		return true, false, registerService()
 	}
 
 	if !*flRunService {
-		return false, nil
+		return false, false, nil
 	}
 
 	interactive, err := svc.IsAnInteractiveSession()
 	if err != nil {
-		return false, err
+		return false, false, err
 	}
 
 	h := &handler{
@@ -285,7 +288,7 @@ func initService(daemonCli *DaemonCli) (bool, error) {
 	if !interactive {
 		log, err = eventlog.Open(*flServiceName)
 		if err != nil {
-			return false, err
+			return false, false, err
 		}
 	}
 
@@ -306,9 +309,9 @@ func initService(daemonCli *DaemonCli) (bool, error) {
 	// Wait for the first signal from the service handler.
 	err = <-h.fromsvc
 	if err != nil {
-		return false, err
+		return false, false, err
 	}
-	return false, nil
+	return false, true, nil
 }
 
 func (h *handler) started() error {