Fix Docker Auth and our V2 registry paths to support library (i.e. namespace-less) repositories.

This support is placed behind a feature flag.

app.py

@@ -50,15 +50,6 @@ DOCKER_V2_SIGNINGKEY_FILENAME = 'docker_v2.pem'
 app = Flask(__name__)
 logger = logging.getLogger(__name__)
 
-
-class RegexConverter(BaseConverter):
-  def __init__(self, url_map, *items):
-    super(RegexConverter, self).__init__(url_map)
-    self.regex = items[0]
-
-
-app.url_map.converters['regex'] = RegexConverter
-
 # Instantiate the configuration.
 is_testing = 'TEST' in os.environ
 is_kubernetes = 'KUBERNETES_SERVICE_HOST' in os.environ
@@ -126,6 +117,41 @@ if app.config['SECRET_KEY'] is None:
 
 features.import_features(app.config)
 
+# Register custom converters.
+class RegexConverter(BaseConverter):
+  """ Converter for handling custom regular expression patterns in paths. """
+  def __init__(self, url_map, *items):
+    super(RegexConverter, self).__init__(url_map)
+    self.regex = items[0]
+
+class RepositoryPathConverter(BaseConverter):
+  """ Converter for handling repository paths. Handles both library and non-library paths (if
+      configured).
+  """
+  def __init__(self, url_map, *items):
+    super(RepositoryPathConverter, self).__init__(url_map)
+    self.weight = 200
+
+    if features.LIBRARY_SUPPORT:
+      # Allow names without namespaces.
+      self.regex = r'[^/]+(/[^/]+)?'
+    else:
+      self.regex = r'([^/]+/[^/]+)'
+
+
+class APIRepositoryPathConverter(BaseConverter):
+  """ Converter for handling repository paths. Does not handle library paths.
+  """
+  def __init__(self, url_map, *items):
+    super(APIRepositoryPathConverter, self).__init__(url_map)
+    self.weight = 200
+    self.regex = r'([^/]+/[^/]+)'
+
+
+app.url_map.converters['regex'] = RegexConverter
+app.url_map.converters['repopath'] = RepositoryPathConverter
+app.url_map.converters['apirepopath'] = APIRepositoryPathConverter
+
 Principal(app, use_sessions=False)
 
 avatar = Avatar(app)