Add support for keep_firing_for in the parser

[felipesere]

This has been merged into Prometheus, Prometheus Operator and is close to done in Thanos.

[prymitive]

Thanks.
Since this affects how long alerts fire and resolve alerts/count check will need to be updated to take it into account, like we do with for - https://github.com/cloudflare/pint/blob/main/internal/checks/alerts_count.go#L95

[codecov-commenter]

Codecov Report

Merging #713 (23fabc4) into main (3e218f6) will increase coverage by 0.27%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #713      +/-   ##
==========================================
+ Coverage   93.63%   93.90%   +0.27%     
==========================================
  Files          85       85              
  Lines        8123     8193      +70     
==========================================
+ Hits         7606     7694      +88     
+ Misses        396      380      -16     
+ Partials      121      119       -2     

Files Changed	Coverage Δ
internal/checks/alerts_count.go	100.00% <100.00%> (ø)
internal/checks/alerts_for.go	100.00% <100.00%> (ø)
internal/checks/rule_for.go	100.00% <100.00%> (ø)
internal/config/for.go	96.87% <100.00%> (+1.22%)	⬆️
internal/config/match.go	99.41% <100.00%> (+0.03%)	⬆️
internal/config/rule.go	100.00% <100.00%> (ø)
internal/parser/models.go	91.11% <100.00%> (+5.56%)	⬆️
internal/parser/parser.go	91.72% <100.00%> (+0.20%)	⬆️

[felipesere]

I'm not sure how to exactly account for keep_firing_for. Does the AlertCount check verify how many "up-flanks" there were - i.e. change from pending to firing?
I wonder if I need to make we don't count any ranges that fall within keep_firing_for of an already counted alert?

[prymitive]

I'm not sure how to exactly account for keep_firing_for. Does the AlertCount check verify how many "up-flanks" there were - i.e. change from pending to firing? I wonder if I need to make we don't count any ranges that fall within keep_firing_for of an already counted alert?

It simply walks over samples from Prometheus range query response.
This needs a lot more changes than just parsing, so I'll add tests for this in alerts/count + add the rest of needed changes.

[prymitive]

• alerts/count
• alerts/for
• rule/for
• config match