Muting certain events

[MOZGIII]

Overview

I am looking for a way to mute certain events at the source level. I found that I can write a regex for event.message to filter the events, but the Go regex engine does not allow for negative lookahead/lookbehind, so writing and maintaining the right regex to allow everything except what I want to filter becomes a mess.

It would be nice if I could write a negative filter, to allow anything except for what is matched by the criteria.

Acceptance Criteria

• Allow negative filters on event.message and event.kind.
• When the criteria matches, the event is ignored, when the criteria does not match the event is processed.

Reason

We need a way to ignore certain cluster events, but allow everything else.

[brampling]

Hi @MOZGIII, thanks for the opening the issue. This is something I also ran into while writing some documentation for Botkube. It's definitely something we need to address and we will look into the best way to implement it.

[pkosiec]

Hi 👋 I'm going to check if a different regex engine (https://github.com/dlclark/regexp2) which supports positive/negative lookahead/lookbehind will do the trick. If yes, it will be fairly easy to implement 🤞Will post an update tomorrow. Cheers!

[MOZGIII]

Hi 👋 I'm going to check if a different regex engine (dlclark/regexp2) which supports positive/negative lookahead/lookbehind will do the trick. If yes, it will be fairly easy to implement 🤞Will post an update tomorrow. Cheers!

It would be better to implement negating filter with a separate regex. There are very practical reasons to not have lookahead/behind in a regex parser, an in this case it can easily be worth a substantial (i.e. more than ~x2) CPU load increase for the same work. It is also more difficult to maintain a lookahead/behind regex than a usual one.

[pkosiec]

Thanks for feedback @MOZGIII. After discussing that f2f inside our team we agreed to go with the Go builtin regex engine and support include/exclude list of regexes, similarly to what we have in the sources[name].kubernetes.namespaces. However, as we're going to publish 0.18RC1 today, I'm afraid it will be moved to the 0.19 release.

[pkosiec]

Hey @MOZGIII, the PR #211 was merged and this functionality will be included in 0.19.
See the updated docs here: https://docs.botkube.io/next/configuration/source/kubernetes#event-and-resource-constraints

You can also try out the unstable main version if you'd like to 🙂