Avoid dead loop when token is string format

The token needs to be a callable object in http.Client, so we assign
a lambda expression to it when it is a string, but current implementation
will cause dead loop since it is x = lambda: x. This patch fixes it
and improves the corresponding test code.

Change-Id: Id41edd705b46196404e5cb3483a290074bde12d0
Closes-Bug: #1301877

ceilometerclient/client.py

@@ -61,8 +61,8 @@ def get_client(api_version, **kwargs):
             * os_tenant_{name|id}: name or ID of tenant
     """
     token = kwargs.get('os_auth_token')
-    if token:
-        token = (token if six.callable(token) else lambda: token)
+    if token and not six.callable(token):
+        token = lambda: kwargs.get('os_auth_token')
 
     if token and kwargs.get('ceilometer_url'):
         endpoint = kwargs.get('ceilometer_url')

ceilometerclient/tests/test_client.py

@@ -41,15 +41,17 @@ class ClientTest(utils.BaseTestCase):
         c2 = self.create_client(api_version=2)
         self.assertIsInstance(c2, v2client.Client)
 
-    def test_client_auth_lambda(self):
-        FAKE_ENV['os_auth_token'] = lambda: FAKE_ENV['os_auth_token']
-        self.assertIsInstance(FAKE_ENV['os_auth_token'],
-                              types.FunctionType)
-        c2 = self.create_client()
-        self.assertIsInstance(c2, v2client.Client)
+    def test_client_auth_token_lambda(self):
+        FAKE_ENV['os_auth_token'] = lambda: '1234'
+        self._test_client_auth_token()
 
-    def test_client_auth_non_lambda(self):
+    def test_client_auth_token_non_lambda(self):
         FAKE_ENV['os_auth_token'] = "1234"
-        self.assertIsInstance(FAKE_ENV['os_auth_token'], str)
+        self._test_client_auth_token()
+
+    def _test_client_auth_token(self):
         c2 = self.create_client()
         self.assertIsInstance(c2, v2client.Client)
+        self.assertIsInstance(c2.http_client.auth_token,
+                              types.FunctionType)
+        self.assertEqual('1234', c2.http_client.auth_token())