Address issues with sync optimization

[dralley]

closes: #9535
https://pulp.plan.io/issues/9535

[pulpbot]

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[goosemania]

If the main repository had changed and subrepos had not changed, subrepos were being excluded from the publication in mirrored metadata mode.

Subrepos that may have changed were not synced if the main repository had not changed

@goosemania Do both of those sound like real issues or am I missing some context that would lead to one of the cases being valid?

I can't think of a situation when those scenarios are valid use cases. I agree that those are issues and the former is more severe, the latter is less critical, imo.

[dralley]

How does i18n work, exactly? If it doesn't translate dynamic arguments then it would be safe to add it here.

[dralley]

I think either Ina or Tanya suggested doing this in the last PR, and combined with the refactoring it does let us ditch this code, which is great: https://github.com/pulp/pulp_rpm/pull/2157/files#diff-fb406f31027edc1c5b65abe7635bbd2830a7cc05c24a487344d7649017d14628L488-L494

[dralley]

@jlsherrill Heads up. Back during the meeting about mirrored metadata, we had discussed whether it should be possible for mirrored-metadata publications to be re-created even if the repositories themselves haven't changed, and no new repository version is created. And I think we agreed to do that for 7.0 / 7.1? (according to the document).

We can actually do that for 3.16.1. Let me know if this would break Katello because we could back off on that change, but if it's beneficial and wouldn't break anything we can keep it.

What happens if mirror=True in 3.14 and 3.15 is:

• If optimize=False OR optimize=True and the sync can't be optimized because some option changed - a new publication will be created ONLY IF a new repository version was created for the main repo. If it was not, no new publication.

• If optimize=True and the main repo (the one where the .treeinfo is located) is the same as the last sync, nothing happens. No new sync happens, no new publication.

What happens in 3.16.1 if mirror=True / sync_policy=mirror_complete will be:

• If optimize=False, or if ANY of the repos (main repo + any .treeinfo repos) have changed since the last sync, all of the syncs will happen, and a new publication will be created regardless of whether a new repository version was created for the main repo.

• If optimize=True and ALL of the repos (main repo + any .treeinfo subrepos) are the same as the last sync, nothing happens. No new sync happens, no new publication.

[jlsherrill]

that all sounds good to me and should 'just work' with katello. I don't forsee any changes needed