Local azure function runtime fails to retrieve a token from the included credentials despite being logged in - azure

Question

I'd like to read blobs in a storage container, based off this Quickstart. I've already been assigned the role of Storage Account Contributor. Using VS code, I followed the tutorial (in VS code) by starting with az login, then start my environment localy, and finally executing the function. I get the following warning:
DefaultAzureCredential failed to retrieve a token from the included credentials.
Attempted credentials:
EnvironmentCredential: EnvironmentCredential authentication unavailable. Environment variables are not fully configured.
Visit https://aka.ms/azsdk/python/identity/environmentcredential/troubleshoot to troubleshoot.this issue.
ManagedIdentityCredential: ManagedIdentityCredential authentication unavailable, no response from the IMDS endpoint.
SharedTokenCacheCredential: SharedTokenCacheCredential authentication unavailable. No accounts were found in the cache.
AzureCliCredential: Failed to invoke Azure CLI
To mitigate this issue, please refer to the troubleshooting guidelines here at https://aka.ms/azsdk/python/identity/defaultazurecredential/troubleshoot.
my code, following the tutorial, looks like:
import azure.functions as func
from azure.storage.blob import BlobServiceClient, BlobClient, ContainerClient
from azure.identity import DefaultAzureCredential
def main(req=None) -> func.HttpResponse:
account_url = "https://<name>.blob.core.windows.net"
default_credential = DefaultAzureCredential()
blob_service_client = BlobServiceClient(account_url, credential=default_credential)
container_client = blob_service_client.get_container_client('<name>')
blob_list = container_client.list_blobs()
for b in blob_list:
return func.HttpResponse(f'{b.name}')
Not sure what else I should do if I've already done the az login part.

Answer 1

I tried in my environment and got below results:
DefaultAzureCredential failed to retrieve a token from the included credentials.
Attempted credentials:
EnvironmentCredential: EnvironmentCredential authentication unavailable. Environment variables are not fully configured.
Visit https://aka.ms/azsdk/python/identity/environmentcredential/troubleshoot to troubleshoot.this issue.
ManagedIdentityCredential: ManagedIdentityCredential authentication unavailable, no response from the IMDS endpoint.
SharedTokenCacheCredential: SharedTokenCacheCredential authentication unavailable. No accounts were found in the cache.
AzureCliCredential: Failed to invoke Azure CLI
To mitigate this issue, please refer to the troubleshooting guidelines here at https://aka.ms/azsdk/python/identity/defaultazurecredential/troubleshoot.
The above error suggest you need to define at least one of the credential like environmentcredential,ManagedIdentitycredential,sharedtokencachecredential,AzureCliCredential. to retrieve token.
You can follow this document to retrieve the token with credential.
I followed the document in terminal I tried az login for signing in and used the below code to get the list of blobs using Http trigger function.
Code:
import azure.functions as func
import logging
from azure.storage.blob import BlobServiceClient, BlobClient, ContainerClient
from azure.identity import DefaultAzureCredential
def main(req=None) -> func.HttpResponse:
logging.info('Python HTTP trigger function processed a request.')
account_url = "https://venkat123.blob.core.windows.net"
default_credential = DefaultAzureCredential()
blob_service_client = BlobServiceClient(account_url, credential=default_credential)
container_name="test"
container_client = blob_service_client.get_container_client(container_name)
#blob_list = container_client.list_blobs()
blobs=[]
for b in container_client.list_blobs():
blobs.append(b.name)
logging.info(b.name)
return func.HttpResponse(f"Listed blobs in container: {blobs}")
The above code executed successfully and listed blobs from the storage container.
Console:
Browser: