googleapis · gkevinzheng · Aug 6, 2024 · May 8, 2024 · May 8, 2024 · May 30, 2024
@@ -90,6 +90,8 @@ def __init__(

        # Save the scopes.
        self._scopes = scopes
+        if not hasattr(self, "_ignore_credentials"):
+            self._ignore_credentials: bool = False

        # If no credentials are provided, then determine the appropriate
        # defaults.
@@ -102,7 +104,7 @@ def __init__(
            credentials, _ = google.auth.load_credentials_from_file(
                credentials_file, **scopes_kwargs, quota_project_id=quota_project_id
            )
-        elif credentials is None:
+        elif credentials is None and not self._ignore_credentials:
            credentials, _ = google.auth.default(
                **scopes_kwargs, quota_project_id=quota_project_id
            )

@@ -53,7 +53,7 @@ def __init__(
        credentials: Optional[ga_credentials.Credentials] = None,
        credentials_file: Optional[str] = None,
        scopes: Optional[Sequence[str]] = None,
-        channel: Optional[grpc.Channel] = None,
+        channel: Optional[Union[grpc.Channel, Callable[..., grpc.Channel]]] = None,
        api_mtls_endpoint: Optional[str] = None,
        client_cert_source: Optional[Callable[[], Tuple[bytes, bytes]]] = None,
        ssl_channel_credentials: Optional[grpc.ChannelCredentials] = None,
@@ -73,14 +73,17 @@ def __init__(
                credentials identify the application to the service; if none
                are specified, the client will attempt to ascertain the
                credentials from the environment.
-                This argument is ignored if ``channel`` is provided.
+                This argument is ignored if a ``channel`` instance is provided.
            credentials_file (Optional[str]): A file with credentials that can
                be loaded with :func:`google.auth.load_credentials_from_file`.
-                This argument is ignored if ``channel`` is provided.
+                This argument is ignored if a ``channel`` instance is provided.
            scopes (Optional(Sequence[str])): A list of scopes. This argument is
-                ignored if ``channel`` is provided.
-            channel (Optional[grpc.Channel]): A ``Channel`` instance through
-                which to make calls.
+                ignored if a ``channel`` instance is provided.
+            channel (Optional[Union[grpc.Channel, Callable[..., grpc.Channel]]]):
+                A ``Channel`` instance through which to make calls, or a Callable
+                that constructs and returns one. If set to None, ``self.create_channel``
+                is used to create the channel. If a Callable is given, it will be called
+                with the same arguments as used in ``self.create_channel``.
            api_mtls_endpoint (Optional[str]): Deprecated. The mutual TLS endpoint.
                If provided, it overrides the ``host`` argument and tries to create
                a mutual TLS channel with client SSL credentials from
@@ -90,11 +93,11 @@ def __init__(
                private key bytes, both in PEM format. It is ignored if
                ``api_mtls_endpoint`` is None.
            ssl_channel_credentials (grpc.ChannelCredentials): SSL credentials
-                for the grpc channel. It is ignored if ``channel`` is provided.
+                for the grpc channel. It is ignored if a ``channel`` instance is provided.
            client_cert_source_for_mtls (Optional[Callable[[], Tuple[bytes, bytes]]]):
                A callback to provide client certificate bytes and private key bytes,
                both in PEM format. It is used to configure a mutual TLS channel. It is
-                ignored if ``channel`` or ``ssl_channel_credentials`` is provided.
+                ignored if a ``channel`` instance or ``ssl_channel_credentials`` is provided.
            quota_project_id (Optional[str]): An optional project to use for billing
                and quota.
            client_info (google.api_core.gapic_v1.client_info.ClientInfo):
@@ -121,9 +124,10 @@ def __init__(
        if client_cert_source:
            warnings.warn("client_cert_source is deprecated", DeprecationWarning)

-        if channel:
+        if isinstance(channel, grpc.Channel):
            # Ignore credentials if a channel was passed.
-            credentials = False
+            credentials = None
+            self._ignore_credentials = True
            # If a channel was explicitly provided, set it.
            self._grpc_channel = channel
            self._ssl_channel_credentials = None
@@ -162,7 +166,9 @@ def __init__(
        )

        if not self._grpc_channel:
-            self._grpc_channel = type(self).create_channel(
+            # initialize with the provided callable or the default channel
+            channel_init = channel or type(self).create_channel
+            self._grpc_channel = channel_init(
                self._host,
                # use the credentials which are saved
                credentials=self._credentials,