As a user, I can have Pulp download content for a repository version

Author: daviddavis (daviddavis)

Redmine Issue: 8324, https://pulp.plan.io/issues/8324

Problem

Consider the following use cases:

1. You want to export a particular repository content but some of its content is on-demand which will cause the export to fail
2. You want to lockdown your allowed content checksums but a particular repository version has remote content with undesired checksums (e.g. md5, sha1)

The current solution we recommend to users is to switch their remote to immediate and sync. This can be problematic for several reasons: maybe your repo version is old and you don't remember the remote you used to create it; maybe it was created from multiple remotes; maybe you don't want to update your remotes' policies; maybe creating a new repo version for your repo is undesirable; etc.

Pulp 2 provided this functionality (pulp-admin repo download --repo-id=zoo) and Satellite Support has asked for this in Pulp 3 so I believe there would be some value in such a feature.

Solution

I suggest we create a way that a user can trigger a download for a specific RepositoryVersion (or maybe even RepositoryVersions) so that its content gets downloaded to storage.

Start by reviewing the stated use cases, the proposed RepositoryVersion download behavior, and Pulp 2's pulp-admin repo download --repo-id=zoo reference. Determine the scope and interface needed to download content for one or more repository versions, then verify that on-demand content is stored and the described export and checksum use cases are covered.