New exception when auth_url is not specified

Certain scenarios into the neutron client will not specify the
auth_url.  This is typically when a token is specified.  However, when
the token is expired the neutron client will attempt to refresh the
token.  Users of this may not have passed in all of the required
information for this reauthentication to properly occur.

This code fixes an error that occurs in this flow where the auth_url
(which is None) is appended to another string.  This results in a core
Python error.

The update will provide a more targetted error message specifying to
the user that the auth_url needs to be specified.  An associated unit
test is also included to validate this behavior.

Change-Id: I577ce0c009a9a281acdc238d290a22c5e561ff82
Closes-Bug: #1241275

neutronclient/client.py

@@ -228,6 +228,9 @@ class HTTPClient(httplib2.Http):
                               'password': self.password, },
                              'tenantName': self.tenant_name, }, }
 
+        if self.auth_url is None:
+            raise exceptions.NoAuthURLProvided()
+
         token_url = self.auth_url + "/tokens"
 
         # Make sure we follow redirects when trying to reach Keystone
@@ -252,6 +255,9 @@ class HTTPClient(httplib2.Http):
         self._extract_service_catalog(resp_body)
 
     def _get_endpoint_url(self):
+        if self.auth_url is None:
+            raise exceptions.NoAuthURLProvided()
+
         url = self.auth_url + '/tokens/%s/endpoints' % self.auth_token
         try:
             resp, body = self._cs_request(url, "GET")

neutronclient/common/exceptions.py

@@ -151,6 +151,10 @@ class BadInputError(Exception):
     pass
 
 
+class NoAuthURLProvided(BadInputError):
+    message = _("auth_url was not provided to the Neutron client")
+
+
 class Error(Exception):
     def __init__(self, message=None):
         super(Error, self).__init__(message)

neutronclient/tests/unit/test_auth.py

@@ -148,6 +148,33 @@ class CLITestAuthKeystone(testtools.TestCase):
         self.mox.ReplayAll()
         self.client.do_request('/resource', 'GET')
 
+    def test_refresh_token_no_auth_url(self):
+        self.mox.StubOutWithMock(self.client, "request")
+        self.client.auth_url = None
+
+        self.client.auth_token = TOKEN
+        self.client.endpoint_url = ENDPOINT_URL
+
+        res401 = self.mox.CreateMock(httplib2.Response)
+        res401.status = 401
+
+        # If a token is expired, neutron server returns 401
+        self.client.request(
+            mox.StrContains(ENDPOINT_URL + '/resource'), 'GET',
+            headers=mox.ContainsKeyValue('X-Auth-Token', TOKEN)
+        ).AndReturn((res401, ''))
+        self.mox.ReplayAll()
+        self.assertRaises(exceptions.NoAuthURLProvided,
+                          self.client.do_request,
+                          '/resource',
+                          'GET')
+
+    def test_get_endpoint_url_with_invalid_auth_url(self):
+        # Handle the case when auth_url is not provided
+        self.client.auth_url = None
+        self.assertRaises(exceptions.NoAuthURLProvided,
+                          self.client._get_endpoint_url)
+
     def test_get_endpoint_url(self):
         self.mox.StubOutWithMock(self.client, "request")