# ------------------------------------
# Copyright (c) Microsoft Corporation.
# Licensed under the MIT License.
# ------------------------------------
from typing import Callable
from azure.core.credentials import TokenCredential
from azure.core.pipeline.policies import BearerTokenCredentialPolicy
from azure.core.pipeline import PipelineRequest, PipelineContext
from azure.core.rest import HttpRequest
def _make_request() -> PipelineRequest[HttpRequest]:
return PipelineRequest(HttpRequest("CredentialWrapper", "https://fakeurl"), PipelineContext(None))
[docs]def get_bearer_token_provider(credential: TokenCredential, *scopes: str) -> Callable[[], str]:
"""Returns a callable that provides a bearer token.
It can be used for instance to write code like:
.. code-block:: python
from azure.identity import DefaultAzureCredential, get_bearer_token_provider
credential = DefaultAzureCredential()
bearer_token_provider = get_bearer_token_provider(credential, "https://cognitiveservices.azure.com/.default")
# Usage
request.headers["Authorization"] = "Bearer " + bearer_token_provider()
:param credential: The credential used to authenticate the request.
:type credential: ~azure.core.credentials.TokenCredential
:param str scopes: The scopes required for the bearer token.
:rtype: callable
:return: A callable that returns a bearer token.
"""
policy = BearerTokenCredentialPolicy(credential, *scopes)
def wrapper() -> str:
request = _make_request()
policy.on_request(request)
return request.http_request.headers["Authorization"][len("Bearer ") :]
return wrapper