feat: Add new Kubernetes Secret backend

[dennislapchenko]

Description

Add a new backend: Kubernetes Secret.

Fixes: #516

Checklist

Please make sure that your PR fulfills the following requirements:

• Reviewed the guidelines for contributing to this repository
• The commit message follows the Conventional Commits Guidelines.
• Tests for the changes have been updated
• Are you adding dependencies? If so, please run go mod tidy -compat=1.17 to ensure only the minimum is pulled in.
• Docs have been added / updated
• Optional. My organization is added to USERS.md.

Type of Change

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• New tests
• Build/CI related changes
• Documentation content changes
• Other (please describe)

[werne2j]

Thanks for the contribution @dennislapchenko! My biggest question is around the idea of the "default" secret and whether it is necessary.

[dennislapchenko]

Thanks for the contribution @dennislapchenko! My biggest question is around the idea of the "default" secret and whether it is necessary.

Cheers @werne2j , I have removed the "default" secret and updated the documentation with [tested] namespace examples.

[dennislapchenko]

hey @werne2j , any info on when this can be released? Or any other comments please?

[dennislapchenko]

Hi @werne2j or @jkayani , apologies for being so persistent.
How would you like to proceed with this? Is everything to your liking?

[jkayani]

Thanks!

[codecov-commenter]

Codecov Report

Merging #521 (6c165be) into main (1934033) will decrease coverage by 0.42%.
The diff coverage is 47.50%.

@@            Coverage Diff             @@
##             main     #521      +/-   ##
==========================================
- Coverage   71.06%   70.65%   -0.42%     
==========================================
  Files          25       26       +1     
  Lines        1911     1949      +38     
==========================================
+ Hits         1358     1377      +19     
- Misses        455      472      +17     
- Partials       98      100       +2     

Impacted Files	Coverage Δ
pkg/kube/client.go	0.00% <0.00%> (ø)
pkg/backends/kubernetessecret.go	53.57% <53.57%> (ø)
pkg/config/config.go	84.40% <100.00%> (+0.25%)	⬆️

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[werne2j]

Thanks @dennislapchenko!

[acelinkio]

Any chance we could cut a new release to close #516 . Super excited to use this!

[dennislapchenko]

Any chance we could cut a new release to close #516 . Super excited to use this!

Agree!

Maybe you can accelerate it if you submit a 1.16 release PR with version bumps (they did similar with 1.15)