This is the plugin_template repository to help plugin writers get started and write their own plugin for Pulp Project 3.0+.

If you are planning on writing a new Pulp plugin, but have no idea what you're doing you've come to the right place. The purpose of this guide is to walk you through, step by step, the Pulp plugin creation process.

This guide specifically details how you write a new content plugin.

Why would you want to write a plugin?

What exactly is this Pulp thing?

It's recommend that you develop on a system that already has Pulp installed. This allows you to test your plugin at every step.

It's also recommended that you go through the planning guide before starting to develop your plugin.

The first step is to bootstrap this template. This will create a functional but useless plugin, with minimal code, docs, and tests. Later on we'll discuss exactly what each part of this template does and what to change to create a 'real' plugin.

1. Clone this repository

   $ git clone https://github.com/pulp/plugin_template.git

   $ cd plugin_template

2. Run the provided bootstrap.py script to create a skeleton for your plugin with the name of your choice. It will contain a setup.py, expected plugin layout and stubs for necessary classes and methods, minimal docs, and tests.

   $ ./bootstrap.py your_plugin_name

   NOTE : Whatever you choose for your_plugin_name will be prefixed with pulp_. Therefore, for this argument it is best to just provide the content type which you would like to support, e.g. rubygem or maven.

In addition to the basic plugin boilerplate, this template also provides a basic set of functional tests using the pulp_smash framework, and a Travis configuration file / scripts for continuous integration. These are highly recommended, as they will make continuous verification of your plugin's functionality much easier.

In order to use these tests, you will need to address the "FIXME" messages left in places where plugin-writer intervention is required.

After bootstrapping, your plugin should be installable and discoverable by Pulp.

1. Install your bootstrapped plugin

   pip install -e your_plugin_name

2. Start/restart the Pulp Server

   django-admin runserver

3. Check that everything worked and you have a remote endpoint

   $ http GET http://localhost:8000/pulp/api/v3/remotes/plugin-template/

The plugin specific /pulp/api/v3/publishers/plugin-template/ and /pulp/api/v3/content/plugin-template/ endpoints should now also be available, and you can validate this by checking the hosted docs http://localhost:8000/pulp/api/v3/docs

Your plugin is discoverable by Pulp because it is a Django application that subclasses pulpcore.plugin.PulpPluginAppConfig

For more information about plugin discoverability, including how it works and plugin entrypoints see the discoverability documentation

First, look at the overview of Pulp Models to understand how Pulp fits these pieces together.

Bootstrapping created three new endpoints (remote, publisher, and content). Additional information should be added to these to tell Pulp how to handle your content.

For each of these three endpoints, the bootstrap has created a model, a serializer and a viewset. The model is how the data is stored in the database. The serializer converts complex data to easily parsable types (XML, JSON). The viewset provides the handlers to serve/receive the serialized data.

Always subclass the relevant model, serializer, and viewset from the pulpcore.plugin namespace. Pulp provides custom behavior for these, and although implementation details are located in pulpcore.app, plugins should always use pulpcore.plugin instead, since pulpcore.plugin gurantees the plugin API semantic versioning

Models:

• model(s) for the specific content type(s) used in plugin, should be subclassed from pulpcore.plugin.models.Content model
• model(s) for the plugin specific remote(s), should be subclassed from pulpcore.plugin.models.Remote model
• model(s) for the plugin specific publisher(s), should be subclassed from pulpcore.plugin.models.Publisher model

Serializers:

• serializer(s) for plugin specific content type(s), should be subclassed from pulpcore.plugin.serializers.ContentSerializer
• serializer(s) for plugin specific remote(s), should be subclassed from pulpcore.plugin.serializers.RemoteSerializer
• serializer(s) for plugin specific publisher(s), should be subclassed from pulpcore.plugin.serializers.PublisherSerializer

Viewsets:

• viewset(s) for plugin specific content type(s), should be subclassed from pulpcore.plugin.viewsets.ContentViewSet
• viewset(s) for plugin specific remote(s), should be subclassed from pulpcore.plugin.viewsets.RemoteViewset
• viewset(s) for plugin specific publisher(s), should be subclassed from pulpcore.plugin.viewsets.PublisherViewset

Keep namespacing in mind when writing your viewsets.

First model your content type. This file is located at pulp_plugin_template/app/models.py. Add any fields that correspond to the metadata of your content, the could be the project name, the author name, or any other type of metadata.

The TYPE class attribute is used for filtering purposes. If a uniqueness constraint is needed, add a Meta class to the model like so:

class PluginTemplateContent(Content):
    TYPE = 'plugin-template'
    filename = models.TextField(unique=True, db_index=True, blank=False)

    class Meta:
        unique_together = ('filename',)

After adding the model, you can run the migration with

pulp-manager makemigrations pulp_plugin_template

And make sure all your fields are on the pulp_plugin_template database table.

Next, add a corresponding serializer field on the in pulp_plugin_template/app/serializers.py. See the DRF documentation on serializer fields to see what's available

Last, add any additional routes to your pulp_plugin_template/app/viewsets.py. The content viewset usually doesn't require any additinal routes, so you can leave this alone for now.

A remote knows specifics of the plugin Content to put it into Pulp. Remote defines how to synchronize remote content. Pulp Platform provides support for concurrent downloading of remote content. Plugin writer is encouraged to use one of them but is not required to.

First model your remote. This file is located at pulp_plugin_template/app/models.py. Add any fields that correspond to the remote source.

Remember to define the TYPE class attribute which is used for filtering purposes,

Next, add a corresponding serializer field on the in pulp_plugin_template/app/serializers.py.

Last, add any additional routes to your pulp_plugin_template/app/viewsets.py. Note the sync route is predefined for you. This route kicks off a task pulp_plugin_template.app.tasks.synchronizing.py.

e. This file is located at pulp_plugin_template/app/models.py. Add any additional fields.

Make sure you define the TYPE class attribute which is used for filtering purposes,

Next, add a corresponding serializer field on the in pulp_plugin_template/app/serializers.py.

Last, add any additional routes to your pulp_plugin_template/app/viewsets.py. Note the publish route is predefined for you. This route kicks off a task pulp_plugin_template.app.tasks.publishing.py.

TODO

Tasks such as sync and publish are needed to tell Pulp how to perform certain actions.

More about Sync task

More about Publish task

More about Export task

TODO

Your bootstrap template comes with a set of prepopulated docs. You can host these on readthedocs when you are ready.

Pulp also comes with a set of auto API docs. When your plugin is installed endpoints in the live api docs will be automatically populate.

• CLI
• Community Development
• Live API
• Error Handling
• Releasing

• Plugin django app is defined using PulpAppConfig as a parent

• Plugin entry point is defined

• pulpcore-plugin is specified as a requirement in setup.py

• Necessary models/serializers/viewsets are defined. At a minimum:

  • models for plugin content type, remote, publisher
  • serializers for plugin content type, remote, publisher
  • viewset for plugin content type, remote, publisher

• Errors are handled according to Pulp conventions

• Docs for plugin are available (any location and format preferred and provided by plugin writer)

A Pulp plugin to support hosting your own plugin-template.

For more information, please see the documentation or the Pulp project page.