fix(upgrade): fix errors during chart version upgrade

[tthvo]

Related to #124

What's changed

• Wrapped new configurations in () for nil-checks. See here.

  • However, this is just for safe guarding, not solving the upgrade failures. See below.

• Create a wrapper that forces helm to use --reset-then-reuse-values. This is available only with helm 3.14+.

  • The user cannot use helm upgrade --reuse-values as it would cause values such as (.Values.storage).image.repository to be empty. This is an invalid image repository.
  • Helm 3.14+ has a new feature with --reset-then-reuse-values: feat(helm): Add --reset-then-reuse-values flag to 'helm upgrade' helm/helm#9653 that fits our upgrade path more.
  • However, chart-testing has not been updated for accommodate that so this is a temporary fix.

• Removed unused test value files (minimal mode is removed).

• Upgraded related github actions.

What's motivation

The test is failing because chart-testing ct is also testing upgrade path with --reuse-values. This causes nil pointer error as old values do not have newly defined fields in 3.0.

Sample run

Sample PR: https://github.com/tthvo/cryostat-helm/actions/runs/9061712431/job/24894069674?pr=7

[andrewazores]

Seems like this makes sense.

[andrewazores]

@ebaron WDYT?

[ebaron]

Thanks for doing this work @tthvo. It's a shame the tester doesn't support this case, since we're not planning on upgrades from 2.x to 3.0 working out of the box in all scenarios.

[tthvo]

I am hoping chart-testing would add a patch to support each upgrade strategy after helm/chart-testing#525. If not, I can try in the next couple days as many might run into the same issues as us :D