Azure Identity client library for Python

The Azure Identity library provides Azure Active Directory (AAD) token authentication through a set of convenient TokenCredential implementations. It enables Azure SDK clients to authenticate with AAD, while also allowing other Python apps to authenticate with AAD work and school accounts, Microsoft personal accounts (MSA), and other Identity providers like AAD B2C service.

Source code | Package (PyPI) | API reference documentation | Azure Active Directory documentation

Disclaimer

Azure SDK Python packages support for Python 2.7 has ended 01 January 2022. For more information and questions, please refer to https://github.com/Azure/azure-sdk-for-python/issues/20691

Getting started

Install the package

Install Azure Identity with pip:

pip install azure-identity

Prerequisites

  • an Azure subscription

  • Python 3.6 or a recent version of Python 3 (this library doesn’t support end-of-life versions)

Authenticate during local development

When debugging and executing code locally it is typical for developers to use their own accounts for authenticating calls to Azure services. The Azure Identity library supports authenticating through developer tools to simplify local development.

Authenticate via Visual Studio Code

Developers using Visual Studio Code can use the Azure Account extension to authenticate via the editor. Apps using DefaultAzureCredential or VisualStudioCodeCredential can then use this account to authenticate calls in their app when running locally.

To authenticate in Visual Studio Code, ensure version 0.9.11 or earlier of the Azure Account extension is installed. To track progress toward supporting newer extension versions, see this GitHub issue. Once installed, open the Command Palette and run the Azure: Sign In command.

Authenticate via the Azure CLI

DefaultAzureCredential and AzureCliCredential can authenticate as the user signed in to the Azure CLI. To sign in to the Azure CLI, run az login. On a system with a default web browser, the Azure CLI will launch the browser to authenticate a user.

When no default browser is available, az login will use the device code authentication flow. This can also be selected manually by running az login --use-device-code.

Key concepts

Credentials

A credential is a class which contains or can obtain the data needed for a service client to authenticate requests. Service clients across the Azure SDK accept a credential instance when they are constructed, and use that credential to authenticate requests.

The Azure Identity library focuses on OAuth authentication with Azure Active Directory (AAD). It offers a variety of credential classes capable of acquiring an AAD access token. See the Credential classes section below for a list of this library’s credential classes.

DefaultAzureCredential

DefaultAzureCredential is appropriate for most applications which will run in the Azure Cloud because it combines common production credentials with development credentials. DefaultAzureCredential attempts to authenticate via the following mechanisms in this order, stopping when one succeeds:

DefaultAzureCredential authentication flow
  • Environment - DefaultAzureCredential will read account information specified via environment variables and use it to authenticate.

  • Managed Identity - if the application is deployed to an Azure host with Managed Identity enabled, DefaultAzureCredential will authenticate with it.

  • Visual Studio Code - if a user has signed in to the Visual Studio Code Azure Account extension, DefaultAzureCredential will authenticate as that user.

  • Azure CLI - if a user has signed in via the Azure CLI az login command, DefaultAzureCredential will authenticate as that user.

  • Azure PowerShell - if a user has signed in via Azure PowerShell’s Connect-AzAccount command, DefaultAzureCredential will authenticate as that user.

  • Interactive - if enabled, DefaultAzureCredential will interactively authenticate a user via the default browser. This is disabled by default.

DefaultAzureCredential is intended to simplify getting started with the SDK by handling common scenarios with reasonable default behaviors. Developers who want more control or whose scenario isn’t served by the default settings should use other credential types.

Managed Identity

DefaultAzureCredential and ManagedIdentityCredential support managed identity authentication in any hosting environment which supports managed identities, such as (this list is not exhaustive):

Examples

The following examples are provided below:

Authenticate with DefaultAzureCredential

More details on configuring your environment to use the DefaultAzureCredential can be found in the class’s reference documentation.

This example demonstrates authenticating the BlobServiceClient from the azure-storage-blob library using DefaultAzureCredential.

from azure.identity import DefaultAzureCredential
from azure.storage.blob import BlobServiceClient

default_credential = DefaultAzureCredential()

client = BlobServiceClient(account_url, credential=default_credential)

Enable interactive authentication with DefaultAzureCredential

Interactive authentication is disabled in the DefaultAzureCredential by default and can be enabled with a keyword argument:

DefaultAzureCredential(exclude_interactive_browser_credential=False)

When enabled, DefaultAzureCredential falls back to interactively authenticating via the system’s default web browser when no other credential is available.

Specify a user assigned managed identity for DefaultAzureCredential

Many Azure hosts allow the assignment of a user assigned managed identity. To configure DefaultAzureCredential to authenticate a user assigned identity, use the managed_identity_client_id keyword argument:

DefaultAzureCredential(managed_identity_client_id=client_id)

Alternatively, set the environment variable AZURE_CLIENT_ID to the identity’s client ID.

Define a custom authentication flow with ChainedTokenCredential

DefaultAzureCredential is generally the quickest way to get started developing applications for Azure. For more advanced scenarios, ChainedTokenCredential links multiple credential instances to be tried sequentially when authenticating. It will try each chained credential in turn until one provides a token or fails to authenticate due to an error.

The following example demonstrates creating a credential which will attempt to authenticate using managed identity, and fall back to authenticating via the Azure CLI when a managed identity is unavailable. This example uses the EventHubProducerClient from the azure-eventhub client library.

from azure.eventhub import EventHubProducerClient
from azure.identity import AzureCliCredential, ChainedTokenCredential, ManagedIdentityCredential

managed_identity = ManagedIdentityCredential()
azure_cli = AzureCliCredential()
credential_chain = ChainedTokenCredential(managed_identity, azure_cli)

client = EventHubProducerClient(namespace, eventhub_name, credential_chain)

Async credentials

This library includes a set of async APIs. To use the async credentials in azure.identity.aio, you must first install an async transport, such as aiohttp. See azure-core documentation for more information.

Async credentials should be closed when they’re no longer needed. Each async credential is an async context manager and defines an async close method. For example:

from azure.identity.aio import DefaultAzureCredential

# call close when the credential is no longer needed
credential = DefaultAzureCredential()
...
await credential.close()

# alternatively, use the credential as an async context manager
credential = DefaultAzureCredential()
async with credential:
  ...

This example demonstrates authenticating the asynchronous SecretClient from azure-keyvault-secrets with an asynchronous credential.

from azure.identity.aio import DefaultAzureCredential
from azure.keyvault.secrets.aio import SecretClient

default_credential = DefaultAzureCredential()
client = SecretClient("https://my-vault.vault.azure.net", default_credential)

Cloud configuration

Credentials default to authenticating to the Azure Active Directory endpoint for Azure Public Cloud. To access resources in other clouds, such as Azure Government or a private cloud, configure credentials with the authority argument. AzureAuthorityHosts defines authorities for well-known clouds:

from azure.identity import AzureAuthorityHosts

DefaultAzureCredential(authority=AzureAuthorityHosts.AZURE_GOVERNMENT)

Not all credentials require this configuration. Credentials which authenticate through a development tool, such as AzureCliCredential, use that tool’s configuration. Similarly, VisualStudioCodeCredential accepts an authority argument but defaults to the authority matching VS Code’s “Azure: Cloud” setting.

Credential classes

Authenticate Azure hosted applications

credential

usage

DefaultAzureCredential

simplified authentication to get started developing applications for the Azure cloud

ChainedTokenCredential

define custom authentication flows composing multiple credentials

EnvironmentCredential

authenticate a service principal or user configured by environment variables

ManagedIdentityCredential

authenticate the managed identity of an Azure resource

Authenticate service principals

credential

usage

ClientSecretCredential

authenticate a service principal using a secret

CertificateCredential

authenticate a service principal using a certificate

Authenticate users

credential

usage

InteractiveBrowserCredential

interactively authenticate a user with the default web browser

DeviceCodeCredential

interactively authenticate a user on a device with limited UI

UsernamePasswordCredential

authenticate a user with a username and password (does not support multi-factor authentication)

Authenticate via development tools

credential

usage

AzureCliCredential

authenticate as the user signed in to the Azure CLI

VisualStudioCodeCredential

authenticate as the user signed in to the Visual Studio Code Azure Account extension

Environment variables

DefaultAzureCredential and EnvironmentCredential can be configured with environment variables. Each type of authentication requires values for specific variables:

variable name

value

AZURE_CLIENT_ID

id of an Azure Active Directory application

AZURE_TENANT_ID

id of the application’s Azure Active Directory tenant

AZURE_CLIENT_SECRET

one of the application’s client secrets

variable name

value

AZURE_CLIENT_ID

id of an Azure Active Directory application

AZURE_TENANT_ID

id of the application’s Azure Active Directory tenant

AZURE_CLIENT_CERTIFICATE_PATH

path to a PEM or PKCS12 certificate file including private key (without password protection)

variable name

value

AZURE_CLIENT_ID

id of an Azure Active Directory application

AZURE_USERNAME

a username (usually an email address)

AZURE_PASSWORD

that user’s password

Configuration is attempted in the above order. For example, if values for a client secret and certificate are both present, the client secret will be used.

Troubleshooting

See the troubleshooting guide for details on how to diagnose various failure scenarios.

Error handling

Credentials raise CredentialUnavailableError when they’re unable to attempt authentication because they lack required data or state. For example, EnvironmentCredential will raise this exception when its configuration is incomplete.

Credentials raise azure.core.exceptions.ClientAuthenticationError when they fail to authenticate. ClientAuthenticationError has a message attribute which describes why authentication failed. When raised by DefaultAzureCredential or ChainedTokenCredential, the message collects error messages from each credential in the chain.

For more details on handling specific Azure Active Directory errors please refer to the Azure Active Directory error code documentation.

Logging

This library uses the standard logging library for logging. Credentials log basic information, including HTTP sessions (URLs, headers, etc.) at INFO level. These log entries do not contain authentication secrets.

Detailed DEBUG level logging, including request/response bodies and header values, is not enabled by default. It can be enabled with the logging_enable argument, for example:

credential = DefaultAzureCredential(logging_enable=True)

CAUTION: DEBUG level logs from credentials contain sensitive information. These logs must be protected to avoid compromising account security.

Next steps

Client library support

Client and management libraries listed on the Azure SDK release page which support Azure AD authentication accept credentials from this library. You can learn more about using these libraries in their documentation, which is linked from the release page.

Known issues

This library doesn’t support Azure AD B2C.

For other open issues, refer to the library’s GitHub repository.

Provide feedback

If you encounter bugs or have suggestions, please open an issue.

Contributing

This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.microsoft.com.

When you submit a pull request, a CLA-bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., label, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.

This project has adopted the Microsoft Open Source Code of Conduct. For more information, see the Code of Conduct FAQ or contact opencode@microsoft.com with any additional questions or comments.

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