restore oauth_uri variable and fix caching

Restores the deleted `oauth_uri` variable of `OAuthAPIClient`. This is a
fix for our ProctorTrack integration, which was relying on the
`oauth_uri` variable as part of the contract. This may or may not be a
long-term solution.

Additionally, since `OAuthAPIClient` can be used to retrieve tokens
against multiple oauth endpoints, we add the oauth_url to the cache key
for the token.

BOM-1184

edx_rest_api_client/__version__.py

@@ -1 +1 @@
-__version__ = '3.0.0'
+__version__ = '3.0.1'

edx_rest_api_client/client.py

@@ -134,10 +134,12 @@ def get_and_cache_oauth_access_token(url, client_id, client_secret, token_type='
         tuple: Tuple containing (access token string, expiration datetime).
 
     """
-    cache_key = 'edx_rest_api_client.access_token.{}.{}.{}'.format(
+    oauth_url = _get_oauth_url(url)
+    cache_key = 'edx_rest_api_client.access_token.{}.{}.{}.{}'.format(
         token_type,
         grant_type,
         client_id,
+        oauth_url,
     )
     cached_response = TieredCache.get_cached_response(cache_key)
 
@@ -151,7 +153,7 @@ def get_and_cache_oauth_access_token(url, client_id, client_secret, token_type='
 
     # Get a new access token if no unexpired access token was found in the cache.
     oauth_access_token_response = get_oauth_access_token(
-        _get_oauth_url(url),
+        oauth_url,
         client_id,
         client_secret,
         grant_type=grant_type,
@@ -176,6 +178,11 @@ class OAuthAPIClient(requests.Session):
     See https://github.com/edx/edx-django-utils/blob/master/edx_django_utils/cache/README.rst#tieredcache
 
     """
+
+    # If the oauth_uri is set, it will be appended to the base_url.
+    # Also, if oauth_uri does not end with `/oauth2/access_token`, it will be adjusted as necessary to do so.
+    oauth_uri = None
+
     def __init__(self, base_url, client_id, client_secret, **kwargs):
         """
         Args:
@@ -189,12 +196,12 @@ def __init__(self, base_url, client_id, client_secret, **kwargs):
         """
         super(OAuthAPIClient, self).__init__(**kwargs)
         self.headers['user-agent'] = USER_AGENT
+        self.auth = SuppliedJwtAuth(None)
+
         self._base_url = base_url.rstrip('/')
         self._client_id = client_id
         self._client_secret = client_secret
 
-        self.auth = SuppliedJwtAuth(None)
-
     def _ensure_authentication(self):
         """
         Ensures that the Session's auth.token is set with an unexpired token.
@@ -203,8 +210,10 @@ def _ensure_authentication(self):
             requests.RequestException if there is a problem retrieving the access token.
 
         """
+        oauth_url = self._base_url if not self.oauth_uri else self._base_url + self.oauth_uri
+
         oauth_access_token_response = get_and_cache_oauth_access_token(
-            self._base_url,
+            oauth_url,
             self._client_id,
             self._client_secret,
             grant_type='client_credentials'

edx_rest_api_client/tests/test_client.py

@@ -24,6 +24,7 @@
 
 URL = 'http://example.com/api/v2'
 OAUTH_URL = "http://test-auth.com/oauth2/access_token"
+OAUTH_URL_2 = "http://test-auth.com/edx/oauth2/access_token"
 SIGNING_KEY = 'edx'
 USERNAME = 'edx'
 FULL_NAME = 'édx äpp'
@@ -180,18 +181,18 @@ def test_token_caching(self):
         """
         Test that tokens are cached based on client, token_type, and grant_type
         """
-        tokens = ['cred4', 'cred3', 'cred2', 'cred1']
+        tokens = [
+            'auth2-cred4', 'auth2-cred3', 'auth2-cred2', 'auth2-cred1',
+            'auth1-cred4', 'auth1-cred3', 'auth1-cred2', 'auth1-cred1',
+        ]
 
         def auth_callback(request):   # pylint: disable=unused-argument
             resp = {'expires_in': 60}
             resp['access_token'] = 'no-more-credentials' if not tokens else tokens.pop()
             return (200, {}, json.dumps(resp))
 
-        responses.add_callback(
-            responses.POST, OAUTH_URL,
-            callback=auth_callback,
-            content_type='application/json',
-        )
+        responses.add_callback(responses.POST, OAUTH_URL, callback=auth_callback, content_type='application/json')
+        responses.add_callback(responses.POST, OAUTH_URL_2, callback=auth_callback, content_type='application/json')
 
         kwargs_list = [
             {'client_id': 'test-id-1', 'token_type': "jwt", 'grant_type': 'client_credentials'},
@@ -200,24 +201,38 @@ def auth_callback(request):   # pylint: disable=unused-argument
             {'client_id': 'test-id-1', 'token_type': "jwt", 'grant_type': 'refresh_token'},
         ]
 
-        # initial requests should call the mock client and get the correct credentials
+        # initial requests to OAUTH_URL should call the mock client and get the correct credentials
         for index, kwargs in enumerate(kwargs_list):
-            token_response = self._get_and_cache_oauth_access_token(**kwargs)
-            expected_token = 'cred{}'.format(index + 1)
+            token_response = self._get_and_cache_oauth_access_token(OAUTH_URL, **kwargs)
+            expected_token = 'auth1-cred{}'.format(index + 1)
             self.assertEqual(token_response[0], expected_token)
         self.assertEqual(len(responses.calls), 4)
 
-        # second set of requests should return the same credentials without making any new mock calls
+        # initial requests to OAUTH_URL_2 should call the mock client and get the correct credentials
         for index, kwargs in enumerate(kwargs_list):
-            token_response = self._get_and_cache_oauth_access_token(**kwargs)
-            expected_token = 'cred{}'.format(index + 1)
+            token_response = self._get_and_cache_oauth_access_token(OAUTH_URL_2, **kwargs)
+            expected_token = 'auth2-cred{}'.format(index + 1)
             self.assertEqual(token_response[0], expected_token)
-        self.assertEqual(len(responses.calls), 4)
+        self.assertEqual(len(responses.calls), 8)
+
+        # second set of requests to OAUTH_URL should return the same credentials without making any new mock calls
+        for index, kwargs in enumerate(kwargs_list):
+            token_response = self._get_and_cache_oauth_access_token(OAUTH_URL, **kwargs)
+            expected_token = 'auth1-cred{}'.format(index + 1)
+            self.assertEqual(token_response[0], expected_token)
+        self.assertEqual(len(responses.calls), 8)
 
-    def _get_and_cache_oauth_access_token(self, client_id, token_type, grant_type):
+        # second set of requests to OAUTH_URL_2 should return the same credentials without making any new mock calls
+        for index, kwargs in enumerate(kwargs_list):
+            token_response = self._get_and_cache_oauth_access_token(OAUTH_URL_2, **kwargs)
+            expected_token = 'auth2-cred{}'.format(index + 1)
+            self.assertEqual(token_response[0], expected_token)
+        self.assertEqual(len(responses.calls), 8)
+
+    def _get_and_cache_oauth_access_token(self, auth_url, client_id, token_type, grant_type):
         refresh_token = 'test-refresh-token' if grant_type == 'refresh_token' else None
         return get_and_cache_oauth_access_token(
-            OAUTH_URL, client_id, 'test-secret', token_type=token_type, grant_type=grant_type,
+            auth_url, client_id, 'test-secret', token_type=token_type, grant_type=grant_type,
             refresh_token=refresh_token,
         )
 
@@ -237,15 +252,22 @@ def setUp(self):
 
     @responses.activate
     @ddt.data(
-        'http://testing.test',
-        'http://testing.test/oauth2',
+        ('http://testing.test', None, 'http://testing.test/oauth2/access_token'),
+        ('http://testing.test', '/edx', 'http://testing.test/edx/oauth2/access_token'),
+        ('http://testing.test', '/edx/oauth2', 'http://testing.test/edx/oauth2/access_token'),
+        ('http://testing.test', '/edx/oauth2/access_token', 'http://testing.test/edx/oauth2/access_token'),
+        ('http://testing.test/oauth2', None, 'http://testing.test/oauth2/access_token'),
+        ('http://testing.test/test', '/edx/oauth2/access_token', 'http://testing.test/test/edx/oauth2/access_token'),
     )
-    def test_automatic_auth(self, client_base_url):
+    @ddt.unpack
+    def test_automatic_auth(self, client_base_url, custom_oauth_uri, expected_oauth_url):
         """
         Test that the JWT token is automatically set
         """
         client_session = OAuthAPIClient(client_base_url, self.client_id, self.client_secret)
-        self._mock_auth_api(self.base_url + '/oauth2/access_token', 200, {'access_token': 'abcd', 'expires_in': 60})
+        client_session.oauth_uri = custom_oauth_uri
+
+        self._mock_auth_api(expected_oauth_url, 200, {'access_token': 'abcd', 'expires_in': 60})
         self._mock_auth_api(self.base_url + '/endpoint', 200, {'status': 'ok'})
         response = client_session.post(self.base_url + '/endpoint', data={'test': 'ok'})
         self.assertIn('client_id=%s' % self.client_id, responses.calls[0].request.body)