allow samples testing for PUT to not have a body

Previously all testing of the PUT method assumed that a body existed,
which is implied by the HTTP spec, but not strictly stated. The tags
api-wg spec specifies an interface with tags that uses PUT with no
payload.

This makes our _do_put able to handle that case, and removes empty
templates when not needed.

Change-Id: I3d869d63affd08e321944c0082ee9865124d38e2

nova/tests/functional/api_sample_tests/test_server_tags.py

@@ -76,8 +76,7 @@ class ServerTagsJsonTest(test_servers.ServersSampleBase):
         tag = models.Tag()
         tag.resource_id = uuid
         tag.tag = 'OtherTag'
-        response = self._do_put('servers/%s/tags/%s' % (uuid, tag.tag),
-                                'server-tags-put-req', {})
+        response = self._do_put('servers/%s/tags/%s' % (uuid, tag.tag))
         self.assertEqual(201, response.status_code)
         expected_location = "%s/servers/%s/tags/%s" % (
             self._get_vers_compute_endpoint(), uuid, tag.tag)

nova/tests/functional/api_samples_test_base.py

@@ -466,8 +466,15 @@ class ApiSampleTestBase(integrated_helpers._IntegratedTestBase):
                 self._write_sample(name, body)
         return self._get_response(url, method, body, headers=headers)
 
-    def _do_put(self, url, name, subs, headers=None):
-        return self._do_post(url, name, subs, method='PUT', headers=headers)
+    def _do_put(self, url, name=None, subs=None, headers=None):
+        # name indicates that we have a body document. While the HTTP
+        # spec implies that PUT is supposed to have one, we have some
+        # APIs which don't.
+        if name:
+            return self._do_post(
+                url, name, subs, method='PUT', headers=headers)
+        else:
+            return self._get_response(url, 'PUT', headers=headers)
 
     def _do_delete(self, url, headers=None):
         return self._get_response(url, 'DELETE', headers=headers)