V1: Stop id changes after the image creation

Currently in v1 if someone tries to update the ID after the image is
created it will cause a 500 to be returned (or if updating to the same
ID a 200). This now returns a 403.

ApiImpact

Change-Id: Ibb40632f027b2b84f88aaf0a971a0f18de350187
Closes-Bug: 1483353
Closes-Bug: 1483688

glance/api/v1/__init__.py

@@ -23,4 +23,4 @@ SUPPORTED_PARAMS = ('limit', 'marker', 'sort_key', 'sort_dir')
 ACTIVE_IMMUTABLE = ('size', 'checksum')
 
 # Metadata which cannot be changed (irrespective of the current image state)
-IMMUTABLE = ('status',)
+IMMUTABLE = ('status', 'id')

glance/tests/unit/v1/test_api.py

@@ -179,6 +179,21 @@ class TestGlanceAPI(base.IsolatedUnitTest):
         self.assertEqual(400, res.status_int)
         self.assertIn('Invalid value', res.body)
 
+    def test_updating_imageid_after_creation(self):
+        # Test incorrect/illegal id update
+        req = webob.Request.blank("/images/%s" % UUID1)
+        req.method = 'PUT'
+        req.headers['x-image-meta-id'] = '000000-000-0000-0000-000'
+        res = req.get_response(self.api)
+        self.assertEqual(403, res.status_int)
+
+        # Test using id of another image
+        req = webob.Request.blank("/images/%s" % UUID1)
+        req.method = 'PUT'
+        req.headers['x-image-meta-id'] = UUID2
+        res = req.get_response(self.api)
+        self.assertEqual(403, res.status_int)
+
     def test_bad_min_disk_size_update(self):
         fixture_headers = {'x-image-meta-disk-format': 'vhd',
                            'x-image-meta-container-format': 'ovf',