Adds support for OIDC, when available

Author: MrMatAP

tests/conftest.py

@@ -20,18 +20,79 @@
 #  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 #  SOFTWARE.
 
+import os
+import logging
+import json
 import pytest
 
+import oauthlib.oauth2
+import requests_oauthlib
+
 from mrmat_python_api_flask import create_app, db
 
+LOGGER = logging.getLogger(__name__)
+
+
+@pytest.fixture
+def test_config():
+    if 'FLASK_CONFIG' not in os.environ:
+        LOGGER.info('Missing test configuration via FLASK_CONFIG environment variable. Tests are limited')
+        return None
+    with open(os.path.expanduser(os.environ['FLASK_CONFIG'])) as C:
+        return json.load(C)
+
 
 @pytest.fixture
 def client():
-    # Note how we override the configuration here, especially how we set an ephemeral in-memory database per test
+    """Start and configure the WSGI app.
+
+    Configuration honours the FLASK_CONFIG environment variable but will set reasonable defaults if not present. This
+    particularly overrides the configuration of an in-memory database rather than the normal persisted database in the
+    instance directory.
+
+    Yields:
+        A Flask client used for testing
+    """
     app = create_app({'TESTING': True, 'SQLALCHEMY_DATABASE_URI': 'sqlite://'})
     with app.app_context():
         db.create_all()
     with app.test_client() as client:
         yield client
 
 
+@pytest.fixture
+def oidc_token(test_config):
+    """Obtain an OIDC token to be used for client testing.
+
+    A token can only be obtained if the configuration file pointed to by the FLASK_CONFIG environment variable
+    contains required entries to set up OIDC for testing. An empty dict is returned if these are not present.
+    The following are required:
+
+    {
+        "web": {                This entry is required to be the very first entry. If you don't like that,
+                                then externalize it into a separate file and point to it via OIDC_CLIENT_SECRETS
+            "client_id":        Server side client_id
+            "client_secret":    Server-side client_secret
+            ...
+        },
+        "client": {
+            "client_id":        Test client client_id
+            "client_secret":    Test client secret
+            "preferred_name":   Asserted preferred_name of the client_id
+        "OIDC_CLIENT_SECRETS":  Point this to the same place as FLASK_CONFIG (to reduce the number of config files
+
+    Yields:
+        A dictionary containing the access token or None if configuration is lacking
+    """
+    if test_config is None or 'client' not in test_config:
+        LOGGER.info('Missing OIDC test client configuration. Tests will be limited')
+        return None
+    for key in ['client_id', 'client_secret', 'preferred_name']:
+        if key not in test_config['client']:
+            LOGGER.info(f'Missing {key} in test client configuration. Tests will be limited')
+            return None
+    client = oauthlib.oauth2.BackendApplicationClient(client_id=test_config['client']['client_id'])
+    oauth = requests_oauthlib.OAuth2Session(client=client)
+    return oauth.fetch_token(token_url=test_config['web']['token_uri'],
+                             client_id=test_config['client']['client_id'],
+                             client_secret=test_config['client']['client_secret'])