This change introduces a new `controller.NewSkipKey` method to designate certain reconciliations as "skipped".
The primary motivation for this is to squelch useless logging on non-leader replicas, which currently report success with trivial latency.
I have plumbed this through existing reconcilers and the code-gen so most things downstream should get this for free. In places where a key is observed, I do not mark the reconcile as skipped as the reconciler did some processing for which the awareness of side-effects and reported latency may be interesting.
We still see users frequently struggle with this and the error message seemingly doesn't help them. This gives a more explicit description of what the user can do to fix the situation.
* Check example-hash label for consistency in ConfigMap webhook.
We've seen users try to edit our configuration and falling into the trap of editing the '_example' block a lot. This attempts at guiding the users to do "the right thing" by checking the ConfigMap's '_example' value (if present) against a precomputed hash of the same value (if present). The idea is that we precompute this has using the tool herein in code generation and thus allow us to easily change the example block automatically while making it hard to change it on ppurpose. If the hashes don't match on an upgrade, the webhook will return an error synchronously, guiding the user to the correct behavior.
* Add tests.
* Add hash check to test utilities.
* Add a bit of coverage.
* Rewrite into a table test.
* Rename.
* Reduce test surface.
* Godoc.
* Code nits.
* Docs.
* Use CRC32.
* Nits.
* Start the webhook before informers sync.
Some webhooks (e.g. conversion) are required to list resources, so by delaying those until after informers have synced, we create a deadlock when they run in the same process. This change has two key parts:
1. Start the webhook immediately when our process starts, and issue a callback from sharedmain when the informers have synced.
2. Block `Admit` calls until informers have synced (all conversions are exempt), unless they have been designated by implementing `webhook.StatelessAdmissionController`.
Our built-in admission controllers (defaulting, validation, configmap validation) have all been marked as stateless, the main case where we want to block `Admit` calls is when we require the informer to have synchronized to populate indices for Bindings.
* Add missing err declaration
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Matt Moore
Victor Agababov
Zbynek Roubalik
Markus Thömmes
Dave Protasowski
Julian Friedman
Matt Moore