# ------------------------------------
# Copyright (c) Microsoft Corporation.
# Licensed under the MIT License.
# ------------------------------------
from typing import TYPE_CHECKING
from azure.core.exceptions import ClientAuthenticationError
from ... import ChainedTokenCredential as SyncChainedTokenCredential
if TYPE_CHECKING:
from typing import Any
from azure.core.credentials import AccessToken
[docs]class ChainedTokenCredential(SyncChainedTokenCredential):
"""A sequence of credentials that is itself a credential.
Its :func:`get_token` method calls ``get_token`` on each credential in the sequence, in order, returning the first
valid token received.
:param credentials: credential instances to form the chain
:type credentials: :class:`azure.core.credentials.TokenCredential`
"""
[docs] async def get_token(self, *scopes: str, **kwargs: "Any") -> "AccessToken": # pylint:disable=unused-argument
"""Asynchronously request a token from each credential, in order, returning the first token received.
If no credential provides a token, raises :class:`azure.core.exceptions.ClientAuthenticationError`
with an error message from each credential.
.. note:: This method is called by Azure SDK clients. It isn't intended for use in application code.
:param str scopes: desired scopes for the token
:raises ~azure.core.exceptions.ClientAuthenticationError:
"""
history = []
for credential in self.credentials:
try:
return await credential.get_token(*scopes, **kwargs)
except ClientAuthenticationError as ex:
history.append((credential, ex.message))
except Exception as ex: # pylint: disable=broad-except
history.append((credential, str(ex)))
error_message = self._get_error_message(history)
raise ClientAuthenticationError(message=error_message)