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azure-identity

README.md

Azure Identity client library for Python

Azure Identity simplifies authentication across the Azure SDK. It supports token authentication using an Azure Active Directory

This library is in preview and currently supports:

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

Getting started

Prerequisites

Install the package

Install Azure Identity with pip:

pip install azure-identity

Creating a Service Principal with the Azure CLI

This library doesn't require a service principal, but Azure applications commonly use them for authentication. If you need to create one, you can use this Azure CLI snippet. Before using it, replace "http://my-application" with a more appropriate name for your service principal.

Create a service principal:

az ad sp create-for-rbac --name http://my-application --skip-assignment

Example output:

{
    "appId": "generated-app-id",
    "displayName": "app-name",
    "name": "http://my-application",
    "password": "random-password",
    "tenant": "tenant-id"
}

Azure Identity can authenticate as this service principal using its tenant id ("tenant" above), client id ("appId" above), and client secret ("password" above).

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 credentials as constructor parameters, as described in their documentation. The next steps section below contains a partial list of client libraries accepting Azure Identity credentials.

Credential classes are found in the azure.identity namespace. They differ in the types of identities they can authenticate as, and in their configuration:

credential class identity configuration
DefaultAzureCredential service principal, managed identity, user none for managed identity, environment variables for service principal or user authentication
ManagedIdentityCredential managed identity none
EnvironmentCredential service principal, user environment variables
ClientSecretCredential service principal constructor parameters
CertificateCredential service principal constructor parameters
DeviceCodeCredential user constructor parameters
InteractiveBrowserCredential user constructor parameters
UsernamePasswordCredential user constructor parameters

Credentials can be chained together and tried in turn until one succeeds; see chaining credentials for details.

Service principal and managed identity credentials have async equivalents in the azure.identity.aio namespace, supported on Python 3.5.3+. See the async credentials example for details. Async user credentials will be part of a future release.

DefaultAzureCredential

DefaultAzureCredential is appropriate for most applications intended to run in Azure. It can authenticate as a service principal, managed identity, or user, and can be configured for local development and production environments without code changes.

To authenticate as a service principal, provide configuration in environment variables as described in the next section.

Authenticating as a managed identity requires no configuration but is only possible in a supported hosting environment. See Azure Active Directory's managed identity documentation for more information.

Single sign-on

During local development on Windows, DefaultAzureCredential can authenticate using a single sign-on shared with Microsoft applications, for example Visual Studio 2019. This may require additional configuration when multiple identities have signed in. In that case, set the environment variable AZURE_USERNAME with the desired identity's username (typically an email address).

Environment variables

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

Service principal with secret

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

Service principal with certificate

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-encoded certificate file including private key (without password protection)

Username and password

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

Note: username/password authentication is not supported by the async API (azure.identity.aio)

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.

Examples

Authenticating with DefaultAzureCredential

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

# This credential first checks environment variables for configuration as described above.
# If environment configuration is incomplete, it will try managed identity.
credential = DefaultAzureCredential()

client = BlobServiceClient(account_url, credential=credential)

Authenticating a service principal with a client secret:

This example demonstrates authenticating the KeyClient from the azure-keyvault-keys library using ClientSecretCredential.

from azure.identity import ClientSecretCredential
from azure.keyvault.keys import KeyClient

credential = ClientSecretCredential(tenant_id, client_id, client_secret)

client = KeyClient("https://my-vault.vault.azure.net", credential)

Authenticating a service principal with a certificate:

This example demonstrates authenticating the SecretClient from the azure-keyvault-secrets library using CertificateCredential.

from azure.identity import CertificateCredential
from azure.keyvault.secrets import SecretClient

# requires a PEM-encoded certificate with private key, not protected with a password
cert_path = "/app/certs/certificate.pem"
credential = CertificateCredential(tenant_id, client_id, cert_path)

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

Chaining credentials:

ChainedTokenCredential links multiple credential instances to be tried sequentially when authenticating. The following example demonstrates creating a credential which will attempt to authenticate using managed identity, and fall back to a service principal if a managed identity is unavailable. This example uses the EventHubClient from the azure-eventhubs client library.

from azure.eventhub import EventHubClient
from azure.identity import ChainedTokenCredential, ClientSecretCredential, ManagedIdentityCredential

managed_identity = ManagedIdentityCredential()
service_principal = ClientSecretCredential(tenant_id, client_id, client_secret)

# when an access token is needed, the chain will try each
# credential in order, stopping when one provides a token
credential_chain = ChainedTokenCredential(managed_identity, service_principal)

# the ChainedTokenCredential can be used anywhere a credential is required
client = EventHubClient(host, event_hub_path, credential_chain)

Async credentials:

This library includes an async API supported on Python 3.5+. 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.

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

# most credentials have async equivalents supported on Python 3.5.3+
from azure.identity.aio import DefaultAzureCredential
from azure.keyvault.secrets.aio import SecretClient

# async credentials have the same API and configuration as their synchronous
# counterparts, and are used with (async) Azure SDK clients in the same way
default_credential = DefaultAzureCredential()
client = SecretClient("https://my-vault.vault.azure.net", default_credential)

Troubleshooting

General

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 Azure Active Directory errors please refer to the Azure Active Directory error code documentation.

Next steps

Client library support

This is an incomplete list of client libraries accepting Azure Identity credentials. You can learn more about these libraries, and find additional documentation of them, at the links below.

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.

Impressions