Migrate thanos-mixin from kube-thanos

[kakkoyun]

This PR moves thanos-mixin from kube-thanos.
Fixes #1180

thanos-mixin is a Jsonnet library to generate monitoring dashboards and Prometheus rules.
For further information on mixins, check out: https://docs.google.com/document/d/1A9xvzwqnFVSOZ5fD3blKODXfsat5fg6ZhnKu9LK3lB4/edit#heading=h.gt9r2h2gklj3

Signed-off-by: Kemal Akkoyun kakkoyun@gmail.com

• I added CHANGELOG entry for this change.
• Change is not relevant to the end user.

TO DO

• Rename Jsonnet dir
• Add README and improve documentation on how to generate examples
• Remove vendor
• Fix broken tests and linter issues

Changes

• Adds thanos-mixin
• Adds necessary Makefile rules to generate rules and dashboards.

Verification

Executed introduced Makefile rules.

[kakkoyun]

cc @metalmatze @GiedriusS @bwplotka

[GiedriusS]

Tried out make examples and make rules-lint. It complains about:

Checking examples/alerts/rules.yaml
3 duplicate rules(s) found.                                                                                                                                                                                          
Metric: :api_range_query_duration_seconds:histogram_quantile                                                                                                                                                         
Label(s):                                                                                                                                                                                                            
        quantile: 0.99                                                                                                                                                                                               
Metric: :http_request_duration_seconds:histogram_quantile                                                                                                                                                            
Label(s):                                                                                                                                                                                                            
        quantile: 0.99
Metric: :thanos_objstore_bucket_operation_duration_seconds:histogram_quantile
Label(s):
        quantile: 0.99
Might cause inconsistency while recording expressions.

Should we fix them before merging or should we leave it for the future? If we would fix them now then we could also add make alerts-test to our CI ❤️

Also, I have checked that md5sum of alerts.yaml and rules.yaml match up with the ones from kube-thanos. I haven't checked the dashboards themselves but at least they get generated successfully.

[GiedriusS]

Also, do we need to add jsonnet/vendor/* to our repositories given that jsonnetfile.lock.json exists?

[bwplotka]

Nice and thanks for doing this!

I just looked on https://github.com/kubernetes-monitoring/kubernetes-mixin and I can see vendor is not pulled, maybe we should do the same for Thanos mixin? I would vote for that as we do not vendor Go deps as well (: WDYT?

Also not sure about jsonnet directory. We don't do go / jsonnet per language dirs, but rather we split functionally, do you think we can actually put it in mixin directory? I like the idea of generating examples, but we might want to add some docs how to update this from mixin (I assume you generated those from that jsonnet) (:

Plus I think README for mixin would be must have for this as it requires totally new tooling.

[kakkoyun]

Thanks a lot for the feedback, I'll address all issues.

I totally agree with vendor, I'll remove it. It's just a reflex to vendor dependencies. I should have followed conventions of the project.

I'm going to rename jsonnet dir to mixin, this sounds good to me.

And I'll also improve documentation.

[kakkoyun]

@GiedriusS @bwplotka this PR is ready for another round :)

[bwplotka]

Nice! I find it interesting that there is mixin/thanos-mixin dirs still, maybe mixin/thanos would make sense? But it's not super critical, happy to merge as it is - let me know.

[GiedriusS]

Yeah, so just a few minor things that were mentioned in-line and I think we can merge this 👍 the changes look good and rules/dashboards make sense. I haven't tried importing them but just glanced over the code. Thanks!

[metalmatze]

Forgot to send my review from a few days ago 🙈

[kakkoyun]

Add fixes that introduced in thanos-io/kube-thanos#74.

[bwplotka]

Some suggestions around Makefile and LGTM!

[kakkoyun]

@bwplotka I've cleaned the Makefile up, PTAL.

[bwplotka]

LGTM mod suggestions. TBH I am fine with merging this and changing those in next PR, this is quite big already.

[kakkoyun]

@GiedriusS @bwplotka @metalmatze I've fixed the pointed issues and renamed the components considering to #1871

[bwplotka]

LGTM 🎉

[metalmatze]

Nice! Thanks for the work on this everybody!