LogQL: Pattern Parser

[cyriltovena]

What this PR does / why we need it:

This PR adds a new parser that is easier to use than the regexp one. See design docs https://docs.google.com/document/d/135OltV_nJgLgryzRhEn5ULgcbwl5bDB6i79IOzMp8IQ/edit

In term of performance it seems to be the fastest parser right now.

Special notes for your reviewer:
See tests for example of usages.

Checklist

• Documentation added
• Tests updated

[dannykopping]

LGTM, left a few grammatical nits.
Didn't spot a test here for a duplicate matcher (i.e. <user> <user>) - did I miss it?

[cyriltovena]

LGTM, left a few grammatical nits.
Didn't spot a test here for a duplicate matcher (i.e. <user> <user>) - did I miss it?

Good point @dannykopping I think we need that check !

[cyriltovena]

LGTM, left a few grammatical nits.
Didn't spot a test here for a duplicate matcher (i.e. <user> <user>) - did I miss it?

Good point @dannykopping I think we need that check !

Ho in fact it's there already https://github.com/cyriltovena/loki/blob/token/pkg/logql/log/pattern/ast.go#L38

[dannykopping]

LGTM, left a few grammatical nits.
Didn't spot a test here for a duplicate matcher (i.e. <user> <user>) - did I miss it?

Good point @dannykopping I think we need that check !

Ho in fact it's there already https://github.com/cyriltovena/loki/blob/token/pkg/logql/log/pattern/ast.go#L38

It's checking for it, but is there a test that explicitly exercises that?

[cyriltovena]

LGTM, left a few grammatical nits.
Didn't spot a test here for a duplicate matcher (i.e. <user> <user>) - did I miss it?

Good point @dannykopping I think we need that check !

Ho in fact it's there already https://github.com/cyriltovena/loki/blob/token/pkg/logql/log/pattern/ast.go#L38

It's checking for it, but is there a test that explicitly exercises that?

https://github.com/cyriltovena/loki/blob/token/pkg/logql/log/pattern/pattern_test.go#L155

[KMiller-Grafana]

I've made suggestions on the documentation portion of this PR. The documentation will be good to go with suggested changes. What a nice parsing addition!

[rbudiharso]

Hi, I'm sorry but is this parser already released?, the documentation on LogQL already have this mentioned and I have Loki version 2.2.1 (the latest one, AFAIK) but I can't use this parser yet

[dannykopping]

Hi @rbudiharso - the feature is not yet released; it'll be included in the upcoming v2.3 release.

The feature is available for use if you build from main, although we don't always guarantee stability on main.

Apologies for the confusion!

[gerardtoconnor]

Hi @dannykopping, do we have an approximate release date for v2.3? I presume/hope will be deployed to Grafana Cloud shortly thereafter?