HumanSignal/label-studio · error · ValueError

Azure account name and key must be set using environment var

Error message

Azure account name and key must be set using environment variables AZURE_BLOB_ACCOUNT_NAME and AZURE_BLOB_ACCOUNT_KEY

What it means

Label Studio's Azure Blob storage integration resolves the account name and key either from explicit parameters or from the AZURE_BLOB_ACCOUNT_NAME and AZURE_BLOB_ACCOUNT_KEY environment variables. get_client_and_container raises this ValueError when, after that fallback, either value is empty, because a BlobServiceClient connection string cannot be built without both credentials.

Source

Thrown at label_studio/io_storages/azure_blob/utils.py:119

        metadata = {
            'ETag': getattr(properties, 'etag', ''),
            'ContentLength': content_length,
            'ContentRange': f'bytes {start}-{actual_end}/{total_size or 0}',
            'LastModified': getattr(properties, 'last_modified', None),
            'StatusCode': status_code,
        }

        return downloader, resolved_content_type, metadata

    @classmethod
    def get_client_and_container(cls, container, account_name=None, account_key=None):
        # get account name and key from params or from environment variables
        account_name = str(account_name) if account_name else get_env('AZURE_BLOB_ACCOUNT_NAME')
        account_key = str(account_key) if account_key else get_env('AZURE_BLOB_ACCOUNT_KEY')
        # check that both account name and key are set
        if not account_name or not account_key:
            raise ValueError(
                'Azure account name and key must be set using '
                'environment variables AZURE_BLOB_ACCOUNT_NAME and AZURE_BLOB_ACCOUNT_KEY'
            )
        connection_string = (
            'DefaultEndpointsProtocol=https;AccountName='
            + account_name
            + ';AccountKey='
            + account_key
            + ';EndpointSuffix=core.windows.net'
        )
        client = BlobServiceClient.from_connection_string(conn_str=connection_string)
        container = client.get_container_client(str(container))
        return client, container

    @classmethod
    def get_blob_metadata(cls, url: str, container: str, account_name: str = None, account_key: str = None) -> dict:
        """
        Get blob metadata by url

View on GitHub (pinned to 0b49e9b539)

Solutions

1. Set both AZURE_BLOB_ACCOUNT_NAME and AZURE_BLOB_ACCOUNT_KEY environment variables in the environment of the Label Studio process (verify with `printenv` inside the container/pod).
2. Alternatively pass account_name and account_key explicitly wherever the storage is configured/validated, e.g. via the storage settings API/JSON.
3. Check for typos in env var names and restart the process after adding them so the env is reloaded.

Example fix

// before
# env: nothing set
cls.get_client_and_container(container='mycontainer')

// after
export AZURE_BLOB_ACCOUNT_NAME=mystorageaccount
export AZURE_BLOB_ACCOUNT_KEY=<base64-key>
# or
cls.get_client_and_container(container='mycontainer', account_name='mystorageaccount', account_key='<base64-key>')

import os
missing = [v for v in ('AZURE_BLOB_ACCOUNT_NAME', 'AZURE_BLOB_ACCOUNT_KEY') if not os.environ.get(v)]
if missing:
    raise EnvironmentError(f'Missing Azure Blob env vars: {missing}')

def has_azure_credentials() -> bool:
    return bool(os.environ.get('AZURE_BLOB_ACCOUNT_NAME')) and bool(os.environ.get('AZURE_BLOB_ACCOUNT_KEY'))

try:
    client, container = AzureBlobStorage.get_client_and_container(container)
except ValueError as e:
    if 'AZURE_BLOB_ACCOUNT' in str(e):
        raise StorageConfigError('Set AZURE_BLOB_ACCOUNT_NAME/AZURE_BLOB_ACCOUNT_KEY env vars') from e
    raise

When it happens

Trigger: Calling get_blob_metadata or validate_pattern (which both call get_client_and_container) when account_name/account_key params are None/empty AND the AZURE_BLOB_ACCOUNT_NAME or AZURE_BLOB_ACCOUNT_KEY environment variables are unset or empty.

Common situations: Deploying Label Studio without exporting the Azure env vars (or exporting them only in a different shell/container than the worker process); typo'd env var names; passing an empty string as account_name; Kubernetes/Docker secret not mounted into the environment.

Understand the failure class

Background: "environment variable is not set" and "Missing keys in environment" errors: what missing required env var messages mean and how to fix them — this error's family across 28 libraries.

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AI-assisted analysis of HumanSignal/label-studio@0b49e9b539 (2026-08-29). Data as JSON: /api/errors/0eb5306549b0b460. Report an issue: GitHub.