From bb45f83319bb26bff1382bd2d86293da26b43d5d Mon Sep 17 00:00:00 2001
From: David Gageot <david@gageot.net>
Date: Sat, 1 Aug 2015 10:12:20 +0200
Subject: [PATCH] FIX #676 - Support Start/Stop GCE instance

Signed-off-by: David Gageot <david@gageot.net>
---
 drivers/google/compute_util.go | 25 +++++++++++++++++
 drivers/google/google.go       | 49 ++++++++++++++++++++--------------
 2 files changed, 54 insertions(+), 20 deletions(-)

diff --git a/drivers/google/compute_util.go b/drivers/google/compute_util.go
index 32fe58e502..563113be9a 100644
--- a/drivers/google/compute_util.go
+++ b/drivers/google/compute_util.go
@@ -284,10 +284,35 @@ func (c *ComputeUtil) deleteInstance() error {
 	if err != nil {
 		return err
 	}
+
 	log.Infof("Waiting for instance to delete.")
 	return c.waitForRegionalOp(op.Name)
 }
 
+// stopInstance stops the instance.
+func (c *ComputeUtil) stopInstance() error {
+	log.Infof("Stopping instance.")
+	op, err := c.service.Instances.Stop(c.project, c.zone, c.instanceName).Do()
+	if err != nil {
+		return err
+	}
+
+	log.Infof("Waiting for instance to stop.")
+	return c.waitForRegionalOp(op.Name)
+}
+
+// startInstance starts the instance.
+func (c *ComputeUtil) startInstance() error {
+	log.Infof("Starting instance.")
+	op, err := c.service.Instances.Start(c.project, c.zone, c.instanceName).Do()
+	if err != nil {
+		return err
+	}
+
+	log.Infof("Waiting for instance to start.")
+	return c.waitForRegionalOp(op.Name)
+}
+
 func (c *ComputeUtil) executeCommands(commands []string, ip, sshKeyPath string) error {
 	for _, command := range commands {
 		auth := &ssh.Auth{
diff --git a/drivers/google/google.go b/drivers/google/google.go
index cd936014bc..67e5484ca0 100644
--- a/drivers/google/google.go
+++ b/drivers/google/google.go
@@ -2,6 +2,7 @@ package google
 
 import (
 	"fmt"
+	"strings"
 
 	"github.com/codegangsta/cli"
 	"github.com/docker/machine/drivers"
@@ -216,32 +217,54 @@ func (d *Driver) GetState() (state.State, error) {
 	return state.None, nil
 }
 
-// Start creates a GCE instance and attaches it to the existing disk.
+// Start starts an existing GCE instance or create an instance with an existing disk.
 func (d *Driver) Start() error {
 	c, err := newComputeUtil(d)
 	if err != nil {
 		return err
 	}
-	if err = c.createInstance(d); err != nil {
-		return err
+
+	instance, err := c.instance()
+	if err != nil {
+		if !strings.Contains(err.Error(), "notFound") {
+			return err
+		}
 	}
+
+	if instance == nil {
+		if err = c.createInstance(d); err != nil {
+			return err
+		}
+	} else {
+		if err := c.startInstance(); err != nil {
+			return err
+		}
+	}
+
 	d.IPAddress, err = d.GetIP()
 	return err
 }
 
-// Stop deletes the GCE instance, but keeps the disk.
+// Stop stops an existing GCE instance.
 func (d *Driver) Stop() error {
 	c, err := newComputeUtil(d)
 	if err != nil {
 		return err
 	}
-	if err = c.deleteInstance(); err != nil {
+
+	if err := c.stopInstance(); err != nil {
 		return err
 	}
+
 	d.IPAddress = ""
 	return nil
 }
 
+// Kill stops an existing GCE instance.
+func (d *Driver) Kill() error {
+	return d.Stop()
+}
+
 // Remove deletes the GCE instance and the disk.
 func (d *Driver) Remove() error {
 	c, err := newComputeUtil(d)
@@ -260,20 +283,6 @@ func (d *Driver) Remove() error {
 	return c.deleteDisk()
 }
 
-// Restart deletes and recreates the GCE instance, keeping the disk.
 func (d *Driver) Restart() error {
-	c, err := newComputeUtil(d)
-	if err != nil {
-		return err
-	}
-	if err := c.deleteInstance(); err != nil {
-		return err
-	}
-
-	return c.createInstance(d)
-}
-
-// Kill deletes the GCE instance, but keeps the disk.
-func (d *Driver) Kill() error {
-	return d.Stop()
+	return nil
 }