feat: Added annotation to skip resource deletion when app is deleted #5945

[JoaoBraveCoding]

Closes #5945

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[codecov]

Codecov Report

Merging #5977 (b955951) into master (b003f70) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #5977   +/-   ##
=======================================
  Coverage   40.95%   40.95%           
=======================================
  Files         147      147           
  Lines       19656    19656           
=======================================
  Hits         8051     8051           
  Misses      10499    10499           
  Partials     1106     1106           

Impacted Files	Coverage Δ
controller/appcontroller.go	53.52% <100.00%> (ø)
util/settings/settings.go	41.46% <0.00%> (ø)

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[JoaoBraveCoding]

/assign @alexmt

[jessesuen]

We discussed this enhancement in today's contributor's meeting and folks were on board with the feature. Some points which were raised:

1. I think we should use key-value options instead of a one-word option. e.g.:

argocd.argoproj.io/delete-options: Policy=Never

This will leave the door open for introducing different policies in the future. An example of where this could be useful, is that Argo CD currently decides not to delete CRDs as a safe default. But for users who do want CRDs to be deleted as part of application delete, we could introduce a:

argocd.argoproj.io/delete-options: Policy=Always

that users could attach to a CRD.

2. How does this interact (if at all) with the existing argocd.argoproj.io/sync-options: Prune=false annotation?

The idea which was discussed was that if someone is specifying argocd.argoproj.io/delete-options: Policy=Never, then it's highly likely they do not want it pruned as well. So I proposed that argocd.argoproj.io/delete-options: Policy=Never would automatically imply argocd.argoproj.io/sync-options: Prune=false. The rationale is that it's hard to come up with a use case where user would want to skip deletion but allow it to get pruned as part of sync. So rather than have users specify both annotations, they could simply specify the delete-option: Policy=Never

3. Finally, this is not necessarily relevant to this PR, but we envision future improvements to delete-options to include support other kubectl delete options: e.g.

• Force=true
• Cascade=Orphan

[crenshaw-dev]

Closing for now. Please feel free to reopen or open a new PR based on this one!