API Authentication

By default, Pulp supports Basic and Session authentication. The Basic Authentication checks the username and password against the internal users database.

Note

This authentication is only for the REST API. Client’s fetching binary data have their identity verified and authorization checked using a ContentGuard.

Which URLs Require Authentication?

All URLs in the REST API require authentication except the Status API, /pulp/api/v3/status/, which is served to unauthenticated users too. This is true regardless of the type of authentication you configure.

Concepts

Authentication in Pulp is provided by Django Rest Framework and Django together.

Django provides the AUTHENTICATION_BACKENDS which defines a set of behaviors to check usernames and passwords against.

Django Rest Framework defines the source usernames and passwords come from with the DEFAULT_AUTHENTICATION_CLASSES setting.

Basic Authentication

Pulp by default uses Basic Authentication which checks the user submitted header against an internal database of users. If the username and password match, the request is considered authenticated as that username.

Below is an example of a Basic Authentication header:

Authorization: Basic YWRtaW46cGFzc3dvcmQ=

You can set this header on an httpie command as follows:

http :80/pulp/api/v3/tasks/ Authorization:"Basic YWRtaW46cGFzc3dvcmQ="

Warning

For the 3.0 release, Pulp expects the user table to have exactly 1 user in it named ‘admin’, which is created automatically when the initial migration is applied. The password for this user can be set with the django-admin reset-admin-password command, but defaults to ‘password’. To articulate what you’d like to see future versions of Pulp file a feature request here or reach out via pulp-list@redhat.com.

Disabling Basic Authentication

Basic Authentication is defined by receiving the username and password encoded in the Authorization header. To disable receiving the username and password using Basic Authentication, remove the rest_framework.authentication.BasicAuthentication from the REST_FRAMEWORK['DEFAULT_AUTHENTICATION_CLASSES'] list.

Disabling Checks against Internal User DB

The internal users database is checked using the django.contrib.auth.backends.ModelBackend from Django. To disable checking a username and password against the internal users database, remote the django.contrib.auth.backends.ModelBackend from the AUTHENTICATION_BACKENDS setting in Pulp.

You can do this effectively, for example using a Python settings file:

AUTHENTICATION_BACKENDS = []

Or as an by defining an environment variable for Dynaconf to use:

export PULP_AUTHENTICATION_BACKEND="[]"

Webserver Authentication

Pulp can be configured to use authentication provided in the webserver outside of Pulp. This allows for integration with ldap for examples, through mod_ldap, or certificate based API access, etc.

Enable external authentication in two steps:

  1. Accept external auth instead of checking the internal users database by enabling:

    ``AUTHENTICATION_BACKENDS = ['pulpcore.app.authentication.PulpNoCreateRemoteUserBackend']``.
    

This will cause Pulp to accept any username for each request and not create a user in the database backend for them. To have any name accepted but create the username in the database backend, use the django.contrib.auth.backends.RemoteUserBackend instead, which creates users by default.

  1. Specify how to receive the username from the webserver. Do this by specifying to DRF an AUTHENTICATION_CLASS. For example, use the PulpRemoteUserAuthentication as follows:

    REST_FRAMEWORK['DEFAULT_AUTHENTICATION_CLASSES'] = (
        'rest_framework.authentication.SessionAuthentication',
        'pulpcore.app.authentication.PulpRemoteUserAuthentication'
    )
    

This removes rest_framework.authentication.BasicAuthentication, and adds PulpRemoteUserAuthentication which accepts the username as WSGI environment variable REMOTE_USER by default, but can be configured via the REMOTE_USER_ENVIRON_NAME Pulp setting.

Webserver Auth in Same Webserver

If your webserver authentication is occurring in the same webserver that is serving the pulpcore.app.wsgi application, you can pass the authenticated username to Pulp via the WSGI environment variable REMOTE_USER.

Reading the REMOTE_USER WSGI environment is the default behavior of the pulpcore.app.authentication.PulpRemoteUserAuthentication and the Django Rest Framework provided rest_framework.authentication.RemoteUserAuthentication. The only difference in the Pulp provided one is that the WSGI environment variable name can be configured from a Pulp provided WSGI environment variable name.

See the REMOTE_USER_ENVIRON_NAME for configuring the WSGI provided name, but if you are using the REMOTE_USER WSGI environment name with “same webserver” authentication, you likely want to leave REMOTE_USER_ENVIRON_NAME unset and configure the webserver to set the REMOTE_USER WSGI environment variable.

Webserver Auth with Reverse Proxy

For example purposes, assume you’re using Nginx with LDAP authentication required and after authenticating it reverse proxies your request to the gunicorn process running the pulpcore.app.wsgi application. That would look like this:

nginx <---http---> gunicorn <----WSGI----> pulpcore.app.wsgi application

With nginx providing authentication, all it can do is pass REMOTE_USER (or similar name) to the application webserver, i.e. gunicorn. You can pass the header as part of the proxy request in nginx with a config line like:

proxy_set_header REMOTE_USER $remote_user;

Per the WSGI standard, any incoming headers will be prepended with a HTTP_. The above line would send the header named REMOTE_USER to gunicorn, and the WSGI application would receive it as HTTP_REMOTE_USER. The default configuration of Pulp is expecting REMOTE_USER in the WSGI environment not HTTP_REMOTE_USER, so this won’t work with pulpcore.app.authentication.PulpRemoteUserAuthentication or the Django Rest Framework provided rest_framework.authentication.RemoteUserAuthentication as is.

Pulp provides a setting named REMOTE_USER_ENVIRON_NAME which allows you to specify another WSGI environment variable to read the authenticated username from.

Warning

Configuring this has serious security implications. See the Django warning at the end of this section in their docs for more details.

Custom Authentication

Pulp is a Django app and Django Rest Framework (DRF) application, so additional authentication can be added as long as it’s correctly configured for both Django and Django Rest Frameowork.

See the Django docs on configuring custom authentication and the Django Rest Framework docs on configuring custom authentication.