Don't return 300 when requesting /versions

Whenever the versions resource is used, it'll reply with a 300 status
code. This is the desired behavior when requesting versions that we
don't support and/or non-existent.

However, when the user requests specifically for the `/versions`
endpoint, Glance shouldn't reply with a 300 since there's just 1 choice
for such endpoint.

APIImpact
Closes-bug: #1491350

Change-Id: I23e3780e5d1b609753ffef59418115f45ab45fe7

glance/api/middleware/version_negotiation.py

@@ -49,7 +49,7 @@ class VersionNegotiationFilter(wsgi.Middleware):
         # If the request is for /versions, just return the versions container
         # TODO(bcwaldon): deprecate this behavior
         if req.path_info_peek() == "versions":
-            return self.versions_app
+            return self.versions_app.index(req, explicit=True)
 
         accept = str(req.accept)
         if accept.startswith('application/vnd.openstack.images-'):

glance/api/versions.py

@@ -41,7 +41,7 @@ class Controller(object):
 
     """A wsgi controller that reports which API versions are supported."""
 
-    def index(self, req):
+    def index(self, req, explicit=False):
         """Respond to a request for all OpenStack API versions."""
         def build_version_object(version, path, status):
             url = CONF.public_endpoint or req.host_url
@@ -73,8 +73,9 @@ class Controller(object):
                 build_version_object(1.0, 'v1', 'SUPPORTED'),
             ])
 
+        status = explicit and http_client.OK or http_client.MULTIPLE_CHOICES
         response = webob.Response(request=req,
-                                  status=http_client.MULTIPLE_CHOICES,
+                                  status=status,
                                   content_type='application/json')
         json = jsonutils.dumps(dict(versions=version_objs))
         if six.PY3:

glance/tests/functional/test_api.py

@@ -295,7 +295,7 @@ class TestApiPaths(functional.FunctionalTest):
         path = 'http://%s:%d/versions' % ('127.0.0.1', self.api_port)
         http = httplib2.Http()
         response, content = http.request(path, 'GET')
-        self.assertEqual(300, response.status)
+        self.assertEqual(200, response.status)
         self.assertEqual(self.versions_json, content)
 
     def test_get_versions_path_with_openstack_header(self):
@@ -307,7 +307,7 @@ class TestApiPaths(functional.FunctionalTest):
         http = httplib2.Http()
         headers = {'Accept': 'application/vnd.openstack.images-v1'}
         response, content = http.request(path, 'GET', headers=headers)
-        self.assertEqual(300, response.status)
+        self.assertEqual(200, response.status)
         self.assertEqual(self.versions_json, content)
 
     def test_get_v1_versions_path(self):

glance/tests/functional/test_ssl.py

@@ -79,6 +79,4 @@ class TestSSL(functional.FunctionalTest):
         path = "https://%s:%d/versions" % ("127.0.0.1", self.api_port)
         https = httplib2.Http(ca_certs=self.ca_file)
         response, content = https.request(path, 'GET')
-
-        # Expect a "300 Multiple Choices"
-        self.assertEqual(300, response.status)
+        self.assertEqual(200, response.status)