[sync-recent-releases.sh] Populate archives.jenkins.io as mirror fallback

[dduportal]

As per jenkins-infra/helpdesk#3828 (comment), the download mirror fallback system was changed to use archives.jenkins.io.

This creates cases when, during a few minutes, a given file is advertised in the mirror system (because already copied by blobxfer) but not yet available in archives.jenkins.io. This is a blocker for security advisories.

This PR is a quick fix to ensure the blocker is removed: it ensures that the scripts syncs archives.jenkins.io once the bits are delivered on OSUOSL. It must be run as second because the source is OSUOSL.

The impact on the execution time varies from 25s to 2m20 based on our history: this will be greatly optimized in the future with 2 mains elements:

• Check if we could replace blobxfer by azcopy helpdesk#3414 => will improve the blobxfer copy time by using azcopy
• [INFRA-3100] Migrate updates.jenkins.io to another Cloud helpdesk#2649 =>should help us to parallelize copies to different locations. Using it here to ensure archives.jenkins.io is populated from pkg is way better.

[daniel-beck]

Note that to a degree it is also a problem during regular use, as the update site advertises plugins that may fail to download. So far, this has been in the range of seconds, but given how frequently the most actively maintained popular plugins release these days, times how long between announcement in JSON and availability, this could be a problem for administrators just periodically updating their plugins.

[dduportal]

Note that to a degree it is also a problem during regular use, as the update site advertises plugins that may fail to download. So far, this has been in the range of seconds, but given how frequently the most actively maintained popular plugins release these days, times how long between announcement in JSON and availability, this could be a problem for administrators just periodically updating their plugins.

Absolutely. We (Jenkins infra team) are going to open an issue and track this subject as priority for March, as it has already created weird behavior during core releases (packages phase: not blocking, nothing unsafe, but annoyance)