helm: Support revisionhistorylimit

[DrFaust92]

What this PR does

Which issue(s) this PR fixes or relates to

Fixes #

Checklist

• Tests updated.
• Documentation added.
• CHANGELOG.md updated - the order of entries should be [CHANGE], [FEATURE], [ENHANCEMENT], [BUGFIX].
• about-versioning.md updated with experimental features.

[narqo]

Thank you for the contribution. I don't mind expanding the chart, but I'd like to know the motivation and the problem that you want to solve with that. Specifically,

• why do we set revisionHistoryLimit: 10 to all workloads — this is the current default in Kubernetes, iirc?
• why would a user want to change the default?

[DrFaust92]

Thank you for the contribution. I don't mind expanding the chart, but I'd like to know the motivation and the problem that you want to solve with that. Specifically,

• why do we set revisionHistoryLimit: 10 to all workloads — this is the current default in Kubernetes, iirc?
• why would a user want to change the default?

• Yes, the default is 10.
• Some cluster operators wish (especially with large clusters) to reduce load on etcd (and argocd tracking objects) and reduce this number .You can see this I a common parameter in charts for things like Argo, Prometheus, and bitnami chart.
  So it's not something exotic either

[narqo]

I've noticed a couple of typos in the changes. Please a look at my comments below.

Also, could you add unit-test for the updated value, so we started to track it as part of the charts API. You can check examples in operations/helm/charts/mimir-distributed/ci/offline (e.g. I think the simplest is to add a new test- values files).

After adding the test,

1. re-build the "golden" files with make build-helm-tests
2. look over the changes in the generated files
3. commit the generated files

With that the future changes in the chart will be tested against these generated values.

[tacole02]

Changelog looks good!

[DrFaust92]

operations/helm/charts/mimir-distributed/ci/offline

Ive made a change to use with otherwise the make build-helm-tests command causes a huge diff in manifests.
Ive added an example of override, creating a dedicated values files with all options seems very excessive