Webserver authentication¶

By default, Airflow requires users to specify a password prior to login. You can use the following CLI commands to create an account:

# create an admin user
airflow users create \
    --username admin \
    --firstname Peter \
    --lastname Parker \
    --role Admin \
    --email spiderman@superhero.org

To deactivate the authentication and allow users to be identified as Anonymous, the following entry in $AIRFLOW_HOME/webserver_config.py needs to be set with the desired role that the Anonymous user will have by default:

AUTH_ROLE_PUBLIC = 'Admin'

Be sure to checkout API for securing the API.

Note

Airflow uses the config parser of Python. This config parser interpolates ‘%’-signs. Make sure escape any % signs in your config file (but not environment variables) as %%, otherwise Airflow might leak these passwords on a config parser exception to a log.

Password¶

One of the simplest mechanisms for authentication is requiring users to specify a password before logging in.

Please use command line interface airflow users create to create accounts, or do that in the UI.

Other Methods¶

Since Airflow 2.0, the default UI is the Flask App Builder RBAC. A webserver_config.py configuration file is automatically generated and can be used to configure the Airflow to support authentication methods like OAuth, OpenID, LDAP, REMOTE_USER. It should be noted that due to the limitation of Flask AppBuilder and Authlib, only a selection of OAuth2 providers is supported. This list includes github, githublocal, twitter, linkedin, google, azure, openshift, okta, keycloak and keycloak_before_17.

The default authentication option described in the Web Authentication section is related with the following entry in the $AIRFLOW_HOME/webserver_config.py.

AUTH_TYPE = AUTH_DB

A WSGI middleware could be used to manage very specific forms of authentication (e.g. SPNEGO) and leverage the REMOTE_USER method:

from typing import Any, Callable

from flask import current_app
from flask_appbuilder.const import AUTH_REMOTE_USER


class CustomMiddleware:
    def __init__(self, wsgi_app: Callable) -> None:
        self.wsgi_app = wsgi_app

    def __call__(self, environ: dict, start_response: Callable) -> Any:
        # Custom authenticating logic here
        # ...
        environ["REMOTE_USER"] = "username"
        return self.wsgi_app(environ, start_response)


current_app.wsgi_app = CustomMiddleware(current_app.wsgi_app)

AUTH_TYPE = AUTH_REMOTE_USER

Another way to create users is in the UI login page, allowing user self registration through a “Register” button. The following entries in the $AIRFLOW_HOME/webserver_config.py can be edited to make it possible:

AUTH_USER_REGISTRATION = True
AUTH_USER_REGISTRATION_ROLE = "Desired Role For The Self Registered User"
RECAPTCHA_PRIVATE_KEY = 'private_key'
RECAPTCHA_PUBLIC_KEY = 'public_key'

MAIL_SERVER = 'smtp.gmail.com'
MAIL_USE_TLS = True
MAIL_USERNAME = 'yourappemail@gmail.com'
MAIL_PASSWORD = 'passwordformail'
MAIL_DEFAULT_SENDER = 'sender@gmail.com'

The package Flask-Mail needs to be installed through pip to allow user self registration since it is a feature provided by the framework Flask-AppBuilder.

To support authentication through a third-party provider, the AUTH_TYPE entry needs to be updated with the desired option like OAuth, OpenID, LDAP, and the lines with references for the chosen option need to have the comments removed and configured in the $AIRFLOW_HOME/webserver_config.py.

For more details, please refer to Security section of FAB documentation.

Example using team based Authorization with GitHub OAuth¶

There are a few steps required in order to use team-based authorization with GitHub OAuth.

configure OAuth through the FAB config in webserver_config.py
create a custom security manager class and supply it to FAB in webserver_config.py
map the roles returned by your security manager class to roles that FAB understands.

Here is an example of what you might have in your webserver_config.py:

from airflow.providers.fab.auth_manager.security_manager.override import FabAirflowSecurityManagerOverride
from flask_appbuilder.security.manager import AUTH_OAUTH
import os

AUTH_TYPE = AUTH_OAUTH
AUTH_ROLES_SYNC_AT_LOGIN = True  # Checks roles on every login
AUTH_USER_REGISTRATION = True  # allow users who are not already in the FAB DB to register

AUTH_ROLES_MAPPING = {
    "Viewer": ["Viewer"],
    "Admin": ["Admin"],
}
# If you wish, you can add multiple OAuth providers.
OAUTH_PROVIDERS = [
    {
        "name": "github",
        "icon": "fa-github",
        "token_key": "access_token",
        "remote_app": {
            "client_id": os.getenv("OAUTH_APP_ID"),
            "client_secret": os.getenv("OAUTH_APP_SECRET"),
            "api_base_url": "https://api.github.com",
            "client_kwargs": {"scope": "read:user, read:org"},
            "access_token_url": "https://github.com/login/oauth/access_token",
            "authorize_url": "https://github.com/login/oauth/authorize",
            "request_token_url": None,
        },
    },
]


class CustomSecurityManager(FabAirflowSecurityManagerOverride):
    pass


# Make sure to replace this with your own implementation of AirflowSecurityManager class
SECURITY_MANAGER_CLASS = CustomSecurityManager

Here is an example of defining a custom security manager. This class must be available in Python’s path, and could be defined in webserver_config.py itself if you wish.

from airflow.providers.fab.auth_manager.security_manager.override import FabAirflowSecurityManagerOverride
import logging
from typing import Any, List, Union
import os

log = logging.getLogger(__name__)
log.setLevel(os.getenv("AIRFLOW__LOGGING__FAB_LOGGING_LEVEL", "INFO"))

FAB_ADMIN_ROLE = "Admin"
FAB_VIEWER_ROLE = "Viewer"
FAB_PUBLIC_ROLE = "Public"  # The "Public" role is given no permissions
TEAM_ID_A_FROM_GITHUB = 123  # Replace these with real team IDs for your org
TEAM_ID_B_FROM_GITHUB = 456  # Replace these with real team IDs for your org


def team_parser(team_payload: dict[str, Any]) -> list[int]:
    # Parse the team payload from GitHub however you want here.
    return [team["id"] for team in team_payload]


def map_roles(team_list: list[int]) -> list[str]:
    # Associate the team IDs with Roles here.
    # The expected output is a list of roles that FAB will use to Authorize the user.

    team_role_map = {
        TEAM_ID_A_FROM_GITHUB: FAB_ADMIN_ROLE,
        TEAM_ID_B_FROM_GITHUB: FAB_VIEWER_ROLE,
    }
    return list(set(team_role_map.get(team, FAB_PUBLIC_ROLE) for team in team_list))


class GithubTeamAuthorizer(FabAirflowSecurityManagerOverride):
    # In this example, the oauth provider == 'github'.
    # If you ever want to support other providers, see how it is done here:
    # https://github.com/dpgaspar/Flask-AppBuilder/blob/master/flask_appbuilder/security/manager.py#L550
    def get_oauth_user_info(self, provider: str, resp: Any) -> dict[str, Union[str, list[str]]]:
        # Creates the user info payload from Github.
        # The user previously allowed your app to act on their behalf,
        #   so now we can query the user and teams endpoints for their data.
        # Username and team membership are added to the payload and returned to FAB.

        remote_app = self.appbuilder.sm.oauth_remotes[provider]
        me = remote_app.get("user")
        user_data = me.json()
        team_data = remote_app.get("user/teams")
        teams = team_parser(team_data.json())
        roles = map_roles(teams)
        log.debug(f"User info from Github: {user_data}\nTeam info from Github: {teams}")
        return {"username": "github_" + user_data.get("login"), "role_keys": roles}

Example using team based Authorization with KeyCloak¶

Here is an example of what you might have in your webserver_config.py:

import os
import jwt
import requests
import logging
from base64 import b64decode
from cryptography.hazmat.primitives import serialization
from flask_appbuilder.security.manager import AUTH_DB, AUTH_OAUTH
from airflow import configuration as conf
from airflow.www.security import AirflowSecurityManager

log = logging.getLogger(__name__)

AUTH_TYPE = AUTH_OAUTH
AUTH_USER_REGISTRATION = True
AUTH_ROLES_SYNC_AT_LOGIN = True
AUTH_USER_REGISTRATION_ROLE = "Viewer"
OIDC_ISSUER = "https://sso.keycloak.me/realms/airflow"

# Make sure you create these role on Keycloak
AUTH_ROLES_MAPPING = {
    "Viewer": ["Viewer"],
    "Admin": ["Admin"],
    "User": ["User"],
    "Public": ["Public"],
    "Op": ["Op"],
}

OAUTH_PROVIDERS = [
    {
        "name": "keycloak",
        "icon": "fa-key",
        "token_key": "access_token",
        "remote_app": {
            "client_id": "airflow",
            "client_secret": "xxx",
            "server_metadata_url": "https://sso.keycloak.me/realms/airflow/.well-known/openid-configuration",
            "api_base_url": "https://sso.keycloak.me/realms/airflow/protocol/openid-connect",
            "client_kwargs": {"scope": "email profile"},
            "access_token_url": "https://sso.keycloak.me/realms/airflow/protocol/openid-connect/token",
            "authorize_url": "https://sso.keycloak.me/realms/airflow/protocol/openid-connect/auth",
            "request_token_url": None,
        },
    }
]

# Fetch public key
req = requests.get(OIDC_ISSUER)
key_der_base64 = req.json()["public_key"]
key_der = b64decode(key_der_base64.encode())
public_key = serialization.load_der_public_key(key_der)


class CustomSecurityManager(AirflowSecurityManager):
    def get_oauth_user_info(self, provider, response):
        if provider == "keycloak":
            token = response["access_token"]
            me = jwt.decode(token, public_key, algorithms=["HS256", "RS256"])

            # Extract roles from resource access
            realm_access = me.get("realm_access", {})
            groups = realm_access.get("roles", [])

            log.info("groups: {0}".format(groups))

            if not groups:
                groups = ["Viewer"]

            userinfo = {
                "username": me.get("preferred_username"),
                "email": me.get("email"),
                "first_name": me.get("given_name"),
                "last_name": me.get("family_name"),
                "role_keys": groups,
            }

            log.info("user info: {0}".format(userinfo))

            return userinfo
        else:
            return {}


# Make sure to replace this with your own implementation of AirflowSecurityManager class
SECURITY_MANAGER_CLASS = CustomSecurityManager