First release of helm chart in new location

[torstenwalter]

This is also the first release of the jenkins chart in the new Github org. The README was updated to reflect the new location.

This also adds https://github.com/github/super-linter GitHub action to validate markdown files.
To ensure a nice contributor experience all linting errors have been fixed.

Note: yaml linting is disabled as Helm templates are no valid yaml.

Closes #3

[scottrigby]

Otherwise looks good!

Also linking a related follow-up issue for Chart.yaml #7

[scottrigby]

👏

[oleg-nenashev]

CC @jenkinsci/code-reviewers

[oleg-nenashev]

Looks good overall! Note that the "Jenkins master" terminology is now deprecated, it would be great to cleanup the terminology in subsequent pull requests

[oleg-nenashev]

Should this file get migrated to the repository root? if not, it might make sense to reference it from README

[torstenwalter]

It\s now referenced from the chart README.

[oleg-nenashev]

These tables might have had some value as user documentation for those who have no immediate access to Helm, but I'd guess maintaining them is difficult

[torstenwalter]

@wmcdona89 added them back in a separate file.

[scottrigby]

Curious why values summary was added back. Generally these are redundant and tend to get out of sync with values.yaml, which hopefully is already readable-ideally more so.

[torstenwalter]

https://github.com/torstenwalter/helm-charts/pull/3#discussion_r479716337

[torstenwalter]

@wmcdona89 I am not really sure if it's a good idea to keep the values table. It's quite some effort to keep it up to date. When removing values or just change the default value of a key one always has to update the table. I think values.yaml should be authorities. We could link to that file in the README instead.

[scottrigby]

It's really up to you all as maintainers of the chart. In my PR to your branch I just applied the same template as proposed for the prometheus charts, for the same reasons: 1. simplifying (charts have become a bit overcomplicated, the repeated README table convention is just one way), 2. easier maintenance (and support for when users get frustrated when table values don't work as expected, since they're manually copied for each chart.values change and periodically are wrong).

If you wanted to automate updating the VALUES_SUMMARY.md every time values.yaml is updated, it could address that 🙂

[torstenwalter]

I added some more changes:

• top-level README now at least contains a reference to the Jenkins chart
• migration steps from one version to another is moved into a migration guide section at the bottom. I think it's something people are only interested once, while the more common use case is to look up configuration examples.
• moved the JCasC configuration to the top of the configuration section as this one is an enabler for users as it allows to make the majority of changes.

I also noticed that we still have XML configuration examples in the README. These should be removed or replaces with JCasC alternatives in future PRs.

[torstenwalter]

I had another look in the file describing the values. What I really like about it is the grouping of related values together. Therefor I am ok with leaving them for now.

Generating it from values.yaml will not provide us the same experience. Using new keys for values to do the grouping will be a breaking change. What we could try is to sort them in the value.yaml the same way and use comments for seperation. Downside is that keys are not sorted alphabetically.

[torstenwalter]

So this PR is up for a last review round. We should try to move future improvements to new PRs to unblock the migration and allow people to contribute.

[wmcdona89]

I opened issue #18 to organize values.yaml to align with the sections in VALUES_SUMMARY. then the README can link to each section in values.yaml and VALUES_SUMMARY can be removed.