Add new key to control reatch disk to vm

cloudstack/resource_cloudstack_disk.go

@@ -93,6 +93,12 @@ func resourceCloudStackDisk() *schema.Resource {
 			},
 
 			"tags": tagsSchema(),
+
+			"reattach_on_change": {
+				Type:     schema.TypeBool,
+				Optional: true,
+				Default:  false,
+			},
 		},
 	}
 }
@@ -216,9 +222,11 @@ func resourceCloudStackDiskUpdate(d *schema.ResourceData, meta interface{}) erro
 	name := d.Get("name").(string)
 
 	if d.HasChange("disk_offering") || d.HasChange("size") {
-		// Detach the volume (re-attach is done at the end of this function)
-		if err := resourceCloudStackDiskDetach(d, meta); err != nil {
-			return fmt.Errorf("Error detaching disk %s from virtual machine: %s", name, err)
+		if d.Get("reattach_on_change").(bool) {
+			// Detach the volume (re-attach is done at the end of this function)
+			if err := resourceCloudStackDiskDetach(d, meta); err != nil {
+				return fmt.Errorf("Error detaching disk %s from virtual machine: %s", name, err)
+			}
 		}
 
 		// Create a new parameter struct

cloudstack/resource_cloudstack_disk_test.go

@@ -116,7 +116,7 @@ func TestAccCloudStackDisk_import(t *testing.T) {
 				ResourceName:            "cloudstack_disk.foo",
 				ImportState:             true,
 				ImportStateVerify:       true,
-				ImportStateVerifyIgnore: []string{"shrink_ok"},
+				ImportStateVerifyIgnore: []string{"shrink_ok", "reattach_on_change"},
 			},
 		},
 	})

website/docs/r/disk.html.markdown

@@ -53,6 +53,9 @@ The following arguments are supported:
 * `zone` - (Required) The name or ID of the zone where this disk volume will be available.
     Changing this forces a new resource to be created.
 
+* `reattach_on_change` - (Optional) Determines whether or not to detach the disk volume
+    from the virtual machine on disk offering or size change.
+
 ## Attributes Reference
 
 The following attributes are exported: