Investigate and document workaround for mirroring gitlab rpm repos via redhat satellite

Summary

There is a long standing issue around repo mirroring not working for our packagecloud repo. The problem is caused by another fix we have in place, and we have longer term goals of getting the issue properly resolved, but in the meantime we need to validate and document our suggested workaround for users.

A summary of the overall issue can be found here: gitlab-org/omnibus-gitlab#2766 (comment 1071104526)

Actions

For this task, we are looking to:

• Investigate workarounds that will work recent versions of RedHat Satellite.
• Document our recommended workaround for users
• If the workaround is something we could implement on our side (perhaps by hosting an additional mirror), open an issue with the proposal so we can evaluate

Other details

Over in gitlab-org/omnibus-gitlab#2766 (closed) our community has suggested some workarounds over the years

The latest workarounds typically do the following

• Sync down the rpms using a known working (with our repo) package downloading software (examples have been reposync, yumdownloader, and cobbler)
• Generate your own rpm repository with the packages, reindexing them yourself (createrepo or cobbler)
• Setup a webserver to serve the packages (custom config via the usuals, or once again, cobbler has this covered)
• Add your new repo to the satellite as an upstream