[Bug] Upgrade not working

[michalpristas]

Upgrade rolls back, because status cannot be fetched by watcher

Repro:

• install 7.x or 8.x (x<8) on Windows (does not need to be managed)
• upgrade to latest 8.8 (using upgrade command and custom source-uri)
• let it run
• after 10 minutes check:
  • agent is running 8.8
  • symlink in Program Files/Elastic/Agent/elastic-agent.exe is pointing to stale version
• restart service it should not boot up

This is because behavior of detecting if agent is installed as running changed: https://github.com/elastic/elastic-agent/pull/2500/files#diff-b62b1d326cae320349cdfca8ed36132a2b3f456042b9b56e34610810c9aa0556

Previously we were checking paths, now we're checking marks.

We could possibly add a fallback check with expected path.

[ycombinator]

Thanks @michalpristas. I'm able to reproduce the issue and am working on a fix.

[EDIT] Since I'm able to reproduce this on MacOS as well, I've removed "windows" from the issue title.

[cmacknz]

Adding the QA:Needs-Validation label to request that the QA team manually test this. It would be valuable for the QA team to test this scenario before the fix is merged to ensure we have a test to catch this problem.

[amolnater-qasource]

Hi Team

We have revalidated agent upgrades from 7.17.10>8.7.1>8.8.0 having Elastic Defend integration in agent policy on 8.8.0 Kibana cloud environment and we had below observations:

• Agent successfully upgraded to latest version following path 7.17.10>8.7.1>8.8.0.

Kibana Build details:

VERSION: 8.8.0
BUILD: 63142
COMMIT: 2973fcc10d985e4ab94e5eeef976aad0046c6cce

Screenshot:

Further we have observed an inconsistent agent behavior on restart, for which we have reported the detailed issue under #2761

Please let us know if we are missing anything here.
Thanks!