As a user, I can rsync content to remote servers

Author: @bmbouter (bmbouter)

Redmine Issue: 5091, https://pulp.plan.io/issues/5091

Problem

To allow remote storage and serving of Pulp content it would be great if an exporter would rsync content to a remote location.

Design

In Pulp3 an 'exporter' can send content out of a Pulp system. An exporter named RsyncExporter should be created that takes the most important option that rsync accepts. Additionally the RsyncExporter takes either a 'repository' or 'repository_version' but not both. If 'repository' it will publish the latest repository_version.

TBD: which fields specifically?

Implementation

Internally it will write the entire repository to a temporary area on-disk and then shell out to rsync. Other ports of rsync-like functionality to Python I don't believe contain the optimization and stability of rsync itself.

On Demand Content

This feature does not work for on-demand content because the content must be present locally for rsync to ship it to the remote system.

Start by reviewing Pulp 3's exporter design and the rsync options the issue identifies as important. Clarify which exporter fields are needed, including the repository versus repository_version choice, then verify that the exporter stages a complete local repository and sends it with rsync while excluding unsupported on-demand content.