Adds Validation Package

[danehans]

Refactors #3477 into a validation pkg that can be used by projectcontour/contour-operator#226 and others.

Signed-off-by: Daneyon Hansen daneyonhansen@gmail.com

[codecov]

Codecov Report

Merging #3499 (16c0fb3) into main (4c319b6) will decrease coverage by 0.02%.
The diff coverage is 100.00%.

❗ Current head 16c0fb3 differs from pull request most recent head 9274cd6. Consider uploading reports for the commit 9274cd6 to get more accurate results

@@            Coverage Diff             @@
##             main    #3499      +/-   ##
==========================================
- Coverage   75.38%   75.35%   -0.03%     
==========================================
  Files          98       98              
  Lines        6614     6606       -8     
==========================================
- Hits         4986     4978       -8     
  Misses       1516     1516              
  Partials      112      112              

Impacted Files	Coverage Δ
internal/dag/gatewayapi_processor.go	80.28% <100.00%> (-2.00%)	⬇️

[skriss]

One option for these validation helpers would be to put them in a new module/repo under projectcontour, with a v0 version, so that we don't have to have compatibility guarantees for now. As soon as they're publicly exported in projectcontour/contour, we're not support to change the API.

I'd like to see some discussion of this vs other approaches for these shared libraries.

[danehans]

Closing in favor of adding validation upstream, xref: kubernetes-sigs/gateway-api#487

[danehans]

xref kubernetes-sigs/gateway-api#597 to add validation pkg upstream.