From b0f815cc58b9dcd50da51a9f6b3da5b9d00f30e2 Mon Sep 17 00:00:00 2001
From: Sam Bashton <sam@bashton.com>
Date: Mon, 5 Jun 2017 18:19:57 +0100
Subject: [PATCH] Allow resizing of Google Cloud persistent disks (#15077)

---
 .../providers/google/resource_compute_disk.go | 24 +++++++++++-
 .../google/resource_compute_disk_test.go      | 39 +++++++++++++++++++
 2 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/builtin/providers/google/resource_compute_disk.go b/builtin/providers/google/resource_compute_disk.go
index bb83a3dc8..294f65479 100644
--- a/builtin/providers/google/resource_compute_disk.go
+++ b/builtin/providers/google/resource_compute_disk.go
@@ -23,6 +23,7 @@ func resourceComputeDisk() *schema.Resource {
 	return &schema.Resource{
 		Create: resourceComputeDiskCreate,
 		Read:   resourceComputeDiskRead,
+		Update: resourceComputeDiskUpdate,
 		Delete: resourceComputeDiskDelete,
 		Importer: &schema.ResourceImporter{
 			State: schema.ImportStatePassthrough,
@@ -68,7 +69,6 @@ func resourceComputeDisk() *schema.Resource {
 			"size": &schema.Schema{
 				Type:     schema.TypeInt,
 				Optional: true,
-				ForceNew: true,
 			},
 
 			"self_link": &schema.Schema{
@@ -185,6 +185,28 @@ func resourceComputeDiskCreate(d *schema.ResourceData, meta interface{}) error {
 	return resourceComputeDiskRead(d, meta)
 }
 
+func resourceComputeDiskUpdate(d *schema.ResourceData, meta interface{}) error {
+	config := meta.(*Config)
+
+	project, err := getProject(d, config)
+	if err != nil {
+		return err
+	}
+
+	if d.HasChange("size") {
+		rb := &compute.DisksResizeRequest{
+			SizeGb: int64(d.Get("size").(int)),
+		}
+		_, err := config.clientCompute.Disks.Resize(
+			project, d.Get("zone").(string), d.Id(), rb).Do()
+		if err != nil {
+			return fmt.Errorf("Error resizing disk: %s", err)
+		}
+	}
+
+	return nil
+}
+
 func resourceComputeDiskRead(d *schema.ResourceData, meta interface{}) error {
 	config := meta.(*Config)
 
diff --git a/builtin/providers/google/resource_compute_disk_test.go b/builtin/providers/google/resource_compute_disk_test.go
index adbd10e12..28288a811 100644
--- a/builtin/providers/google/resource_compute_disk_test.go
+++ b/builtin/providers/google/resource_compute_disk_test.go
@@ -32,6 +32,34 @@ func TestAccComputeDisk_basic(t *testing.T) {
 	})
 }
 
+func TestAccComputeDisk_updateSize(t *testing.T) {
+	diskName := fmt.Sprintf("tf-test-%s", acctest.RandString(10))
+	var disk compute.Disk
+
+	resource.Test(t, resource.TestCase{
+		PreCheck:  func() { testAccPreCheck(t) },
+		Providers: testAccProviders,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccComputeDisk_basic(diskName),
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckComputeDiskExists(
+						"google_compute_disk.foobar", &disk),
+					resource.TestCheckResourceAttr("google_compute_disk.foobar", "size", "50"),
+				),
+			},
+			{
+				Config: testAccComputeDisk_resized(diskName),
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckComputeDiskExists(
+						"google_compute_disk.foobar", &disk),
+					resource.TestCheckResourceAttr("google_compute_disk.foobar", "size", "100"),
+				),
+			},
+		},
+	})
+}
+
 func TestAccComputeDisk_fromSnapshotURI(t *testing.T) {
 	diskName := fmt.Sprintf("tf-test-%s", acctest.RandString(10))
 	firstDiskName := fmt.Sprintf("tf-test-%s", acctest.RandString(10))
@@ -212,6 +240,17 @@ resource "google_compute_disk" "foobar" {
 }`, diskName)
 }
 
+func testAccComputeDisk_resized(diskName string) string {
+	return fmt.Sprintf(`
+resource "google_compute_disk" "foobar" {
+	name = "%s"
+	image = "debian-8-jessie-v20160803"
+	size = 100
+	type = "pd-ssd"
+	zone = "us-central1-a"
+}`, diskName)
+}
+
 func testAccComputeDisk_fromSnapshotURI(firstDiskName, snapshotName, diskName, xpn_host string) string {
 	return fmt.Sprintf(`
 		resource "google_compute_disk" "foobar" {