From ccb34b702d43885ead76630c2351985b0597a9f2 Mon Sep 17 00:00:00 2001
From: Julien Pivotto <roidelapluie@gmail.com>
Date: Thu, 27 Apr 2017 19:48:58 +0200
Subject: [PATCH] provider/digitalocean: prevent new resources when using ID's
 of images with slugs (#13879)

When you specify the ID of an image that has a slug, terraform would
store its slug to the state, hence it would always recreate the image.

This commit fixes it by storing the image as an ID when it is specified
by and ID by the user, ignoring the slug.

Closes #12751.
Fixes #12255.

Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>
---
 .../resource_digitalocean_droplet.go          |  9 ++++--
 .../resource_digitalocean_droplet_test.go     | 31 +++++++++++++++++++
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/builtin/providers/digitalocean/resource_digitalocean_droplet.go b/builtin/providers/digitalocean/resource_digitalocean_droplet.go
index 48372d0e7..fdae4dd03 100644
--- a/builtin/providers/digitalocean/resource_digitalocean_droplet.go
+++ b/builtin/providers/digitalocean/resource_digitalocean_droplet.go
@@ -260,10 +260,13 @@ func resourceDigitalOceanDropletRead(d *schema.ResourceData, meta interface{}) e
 		return fmt.Errorf("Error retrieving droplet: %s", err)
 	}
 
-	if droplet.Image.Slug != "" {
-		d.Set("image", droplet.Image.Slug)
-	} else {
+	_, err = strconv.Atoi(d.Get("image").(string))
+	if err == nil || droplet.Image.Slug == "" {
+		// The image field is provided as an ID (number), or
+		// the image bash no slug. In both cases we store it as an ID.
 		d.Set("image", droplet.Image.ID)
+	} else {
+		d.Set("image", droplet.Image.Slug)
 	}
 
 	d.Set("name", droplet.Name)
diff --git a/builtin/providers/digitalocean/resource_digitalocean_droplet_test.go b/builtin/providers/digitalocean/resource_digitalocean_droplet_test.go
index 1daa64787..1d6f78042 100644
--- a/builtin/providers/digitalocean/resource_digitalocean_droplet_test.go
+++ b/builtin/providers/digitalocean/resource_digitalocean_droplet_test.go
@@ -46,6 +46,26 @@ func TestAccDigitalOceanDroplet_Basic(t *testing.T) {
 	})
 }
 
+func TestAccDigitalOceanDroplet_WithID(t *testing.T) {
+	var droplet godo.Droplet
+	rInt := acctest.RandInt()
+	// TODO: not hardcode this as it will change over time
+	centosID := 22995941
+
+	resource.Test(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testAccCheckDigitalOceanDropletDestroy,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccCheckDigitalOceanDropletConfig_withID(centosID, rInt),
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckDigitalOceanDropletExists("digitalocean_droplet.foobar", &droplet),
+				),
+			},
+		},
+	})
+}
 func TestAccDigitalOceanDroplet_withSSH(t *testing.T) {
 	var droplet godo.Droplet
 	rInt := acctest.RandInt()
@@ -499,6 +519,17 @@ resource "digitalocean_droplet" "foobar" {
 }`, rInt)
 }
 
+func testAccCheckDigitalOceanDropletConfig_withID(imageID, rInt int) string {
+	return fmt.Sprintf(`
+resource "digitalocean_droplet" "foobar" {
+  name      = "foo-%d"
+  size      = "512mb"
+  image     = "%d"
+  region    = "nyc3"
+  user_data = "foobar"
+}`, rInt, imageID)
+}
+
 func testAccCheckDigitalOceanDropletConfig_withSSH(rInt int) string {
 	return fmt.Sprintf(`
 resource "digitalocean_ssh_key" "foobar" {