Update alerting_rules.md

[justinwalz]

Docs only change. Fix ALERTS example to use regex.

[roidelapluie]

Thanks for your PR.

This is not a promql expression, therefore I don't think this should be fixed.

[justinwalz]

Interesting. Why's that?

Someone could be reading the docs, see this expression, copy and paste it into their expression executor, run it, and not seeing anything.

Copy:

ALERTS{alertname="<alert name>", alertstate="pending|firing", <additional alert labels>}

Paste and Adjust to:

ALERTS{alertstate="pending|firing"}

No results, head-scratch. Or simply believe they don't have any firing or pending alerts.

[roidelapluie]

Mmh indeed it does not seem harmful.

[roidelapluie]

We have discussed this in the bug scrub and decided that in both case this is confusing, we should improve that part of the documentation to make it more meta-syntactic.

Something like alertstate="<pending or firing>".

Are you willing to update this pull request in that direction? Thanks!

[justinwalz]

Sure thing, that works for me. Updated.

[brian-brazil]

Thanks!