Don't try to get aodh endpoint if auth_url didn't provided

This change includes:

* Allow users of ceilometerclient specifying aodh_endpoint explicitly
* If aodh_endpoint didn't provided and users just provide ceilometer
  endpoint and token, no auth_url, we assume aodh is unavailable and
  avoid trying to get aodh endpoint.

Change-Id: Idd0ce60058d23507a99b89926e461d19db267ca2
Closes-Bug: #1488290

ceilometerclient/tests/unit/test_client.py

@@ -371,6 +371,15 @@ class ClientAuthTest(utils.BaseTestCase):
         session_instance_mock.get_endpoint.assert_called_with(
             region_name=None, interface='publicURL', service_type='alarming')
 
+    def test_get_aodh_endpoint_without_auth_url(self):
+        env = FAKE_ENV.copy()
+        env.pop('auth_plugin', None)
+        env.pop('endpoint', None)
+        env.pop('auth_url', None)
+        client = self.create_client(env, endpoint='fake_endpoint')
+        self.assertEqual(client.alarm_auth_plugin.opts,
+                         client.auth_plugin.opts)
+
     @mock.patch('ceilometerclient.client._get_keystone_session')
     @mock.patch('ceilometerclient.client._get_token_auth_ks_session')
     def test_get_different_endpoint_type(self, token_session, session):

ceilometerclient/v2/client.py

@@ -87,14 +87,25 @@ class Client(object):
 
     def _get_alarm_client(self, **kwargs):
         """Get client for alarm manager that redirect to aodh."""
+
         self.alarm_auth_plugin = copy.deepcopy(self.auth_plugin)
-        try:
-            # NOTE(liusheng): Getting the aodh's endpoint to rewrite
-            # the endpoint of alarm auth_plugin.
-            self.alarm_auth_plugin.redirect_to_aodh_endpoint(
-                kwargs.get('timeout'))
-        except exceptions.EndpointNotFound:
+        aodh_endpoint = kwargs.get('aodh_endpoint')
+        if aodh_endpoint:
+            self.alarm_auth_plugin.opts['endpoint'] = aodh_endpoint
+        elif not kwargs.get('auth_url'):
+            # Users may just provided ceilometer endpoint and token, and no
+            # auth_url, in this case, we need 'aodh_endpoint' also provided,
+            # otherwise we cannot get aodh endpoint from keystone, and assume
+            # aodh is unavailable.
             return self.http_client, False
+        else:
+            try:
+                # NOTE(liusheng): Getting the aodh's endpoint to rewrite
+                # the endpoint of alarm auth_plugin.
+                self.alarm_auth_plugin.redirect_to_aodh_endpoint(
+                    kwargs.get('timeout'))
+            except exceptions.EndpointNotFound:
+                return self.http_client, False
         alarm_client = client.HTTPClient(
             auth_plugin=self.alarm_auth_plugin,
             region_name=kwargs.get('region_name'),