Architecture and Deploying¶
Pulp’s architecture has three components to it: a REST API, a content serving application, and the tasking system. Each component can be horizontally scaled for both high availability and/or additional capacity for that part of the architecture.
Pulp’s REST API is a Django application which runs under any WSGI server. It serves the following things:
The REST API hosted at
The browse-able documentation at
Any viewsets or views provided by plugins
Static content used by Django, e.g. images used by the browse-able API. This is not Pulp content.
A simple, but limited way to run the REST API as a standalone service using the built-in Django runserver.:
$ python django-admin runserver 24817
The REST API can be deployed with any any WSGI webserver like a normal Django application. See the Django deployment docs for more information.
Content Serving Application¶
An aiohttp.server based application that serves content to clients. The content could be Artifacts already downloaded and saved in Pulp, or on-demand content units. When serving on-demand content units the downloading also happens from within this component as well.
Pulp installs a script that lets you run the content serving app as a standalone service as follows::
The content serving application can be deployed like any aiohttp.server application. See the aiohttp Deployment docs for more information.
Pulp’s tasking system has two components: a resource manager and workers, all of which are run using rq.
Pulp workers perform most tasks “run” by the tasking system including long-running tasks like synchronize and short-running tasks like a Distribution update. Each worker handles one task at a time, and additional workers provide more concurrency. Workers auto-name and are auto-discovered, so they can be started and stopped without notifying Pulp.
- Resource Manager
A different type of Pulp worker that plays a coordinating role for the tasking system. You must run exactly one of these for Pulp to operate correctly. The
resource-manageris identified by configuring using exactly the name
resource-managerrq processes can be started with 1 being active and N-1 being passive. The N-1 will exit and should be configured to auto-relaunch with either systemd, supervisord, or k8s.
Pulp serializes tasks that are unsafe to run in parallel, e.g. a sync and publish operation on the same repo should not run in parallel. Generally tasks are serialized at the “repo” level, so if you start N workers you can process N repo sync/modify/publish operations concurrently.
When browsing the REST API or the browsable documentation with a web browser, for a good experience, you’ll need static content to be served.
If using the built-in Django webserver and your settings.yaml has
DEBUG: True then static
content is automatically served for you.
Collect all of the static content into place using the
$ django-admin collectstatic