feat: Gator sync test support

[anlandu]

What this PR does / why we need it:
Certain templates require replicating into OPA to enable correct evaluation. These templates can use the annotation metadata.gatekeeper.sh/requires-sync-data to indicate which resources need to be synced. This template annotation is descriptive, not prescriptive. The prescription of which resources to sync is done in SyncSet resources and/or the Gatekeeper Config resource. The management of these various requirements can get challenging as the number of templates requiring replicated data increases.

gator sync test aims to mitigate this challenge by enabling the user to verify their sync configuration is correct. The user passes in any number of Constraint Templates, SyncSets, and a Gatekeeper Config object, along with a GVK manifest listing the GVKs supported by the cluster under test, and the command will determine which requirements enumerated by the Constraint Templates are unfulfilled by the given SyncSet(s), Config, and/or manifest.

PRD

Which issue(s) this PR fixes (optional, using fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when the PR gets merged):
xref #2393

Special notes for your reviewer:

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 35.67961% with 265 lines in your changes missing coverage. Please review.

Project coverage is 47.48%. Comparing base (3350319) to head (3854ad2).
Report is 168 commits behind head on master.

Files with missing lines	Patch %	Lines
apis/gvkmanifest/v1alpha1/zz_generated.deepcopy.go	0.00%	120 Missing ⚠️
pkg/gator/reader/read_resources.go	0.00%	69 Missing ⚠️
cmd/gator/sync/test/test.go	0.00%	31 Missing ⚠️
pkg/gator/sync/test/test.go	78.57%	17 Missing and 7 partials ⚠️
pkg/cachemanager/parser/syncannotationreader.go	27.27%	16 Missing ⚠️
cmd/gator/sync/sync.go	0.00%	5 Missing ⚠️

❗ There is a different number of reports uploaded between BASE (3350319) and HEAD (3854ad2). Click for more details.

HEAD has 1 upload less than BASE

Flag	BASE (3350319)	HEAD (3854ad2)
unittests	2	1

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3098      +/-   ##
==========================================
- Coverage   54.49%   47.48%   -7.02%     
==========================================
  Files         134      228      +94     
  Lines       12329    19086    +6757     
==========================================
+ Hits         6719     9063    +2344     
- Misses       5116     9177    +4061     
- Partials      494      846     +352     

Flag	Coverage Δ
unittests	47.48% <35.67%> (-7.02%)	⬇️

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[anlandu]

@julianKatz @acpana

[acpana]

This looks really good 💯 !! Thanks for working on it.

A few questions and suggestions.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 14 days if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 14 days if no further activity occurs. Thank you for your contributions.

[sozercan]

@anlandu are you still interested in getting this to be merged?

[anlandu]

@sozercan yep! Happy to update the branch and address any comments anyone has, or Alex and Julian took a pretty thorough look so I can just merge it without waiting for another review

[ritazh]

@anlandu looks like there are some lint and unit test failures. can you PTAL?

[anlandu]

@anlandu looks like there are some lint and unit test failures. can you PTAL?

@ritazh sorry for the delay during oncall! I've fixed them now

[ritazh]

LGTM

[ritazh]

@maxsmythe LGTY?

[maxsmythe]

LGTM with one nit