Fix TestHeadlessAuthenticationWatcher flakiness#24562
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…ing waiters as stale by accident.
mdwn
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Apr 14, 2023
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Overall this looks good to me. I've got two questions, but feel free to push back on these.
codingllama
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Thanks for the fix, Brian!
| select { | ||
| case t := <-h.retry.After(): | ||
| h.Log.Debugf("Attempting to restart watch after waiting %v.", t.Sub(startedWaiting)) | ||
| h.Log.Warningf("Restarting watch on error after waiting %v. Error: %v.", t.Sub(startedWaiting), err) |
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Does h.watch always return a non-nil error? I'm a bit confused by the error handling here.
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Yes, h.watch should always return non-nil error, and we want to restart the watcher on any error received, unless it's a context canceled/deadline error or the watcher is closed, which is covered by the select case.
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I like the new approach. See comments for some minor suggestions.
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After repeatedly getting
TestHeadlessAuthenticationWatcherflakiness and mistakenly just shifting the problem around, I decided this time to restructure the headless watcher and subscriber logic to make testing without race conditions possible.For context, the headless authentication watcher uses a stale channel to skip slow subscribers. Subscribers are expected to watch the stale channel and check the backend on receive. This PR breaks out this logic from the single
headlessAuthenticationWatcher.Waitmethod into a newHeadlessAuthenticationSubscriberinterface. This interface gives tests more insight into the stale mechanism, etc, without creating// Only used in testsbackdoors into the watcher.This change also makes the TestHeadlessAuthenticationWatcher much faster 🚀 since it avoids unstable waiting/ticking logic.
Closes #24409