fix: make image digest check more permissive

[lkingland]

Makes the image digest check and validation a bit more permissive.

Fixes #2508

/kind bug

Fixes a bug where registries could sometimes not specify port

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 66.90%. Comparing base (c489f7f) to head (1be1e14).
Report is 4 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2510      +/-   ##
==========================================
+ Coverage   61.47%   66.90%   +5.42%     
==========================================
  Files         129      130       +1     
  Lines       15381    12048    -3333     
==========================================
- Hits         9456     8061    -1395     
+ Misses       4990     3010    -1980     
- Partials      935      977      +42     

Flag	Coverage Δ
e2e-test	36.52% <60.00%> (-0.08%)	⬇️
e2e-test-oncluster	33.36% <60.00%> (-0.07%)	⬇️
e2e-test-oncluster-runtime	29.70% <60.00%> (?)
e2e-test-runtime-go	26.56% <60.00%> (?)
e2e-test-runtime-node	25.95% <60.00%> (?)
e2e-test-runtime-python	25.95% <60.00%> (?)
e2e-test-runtime-quarkus	26.05% <60.00%> (?)
e2e-test-runtime-rust	25.08% <60.00%> (?)
e2e-test-runtime-springboot	25.13% <60.00%> (?)
e2e-test-runtime-typescript	26.04% <60.00%> (?)
integration-tests	53.04% <100.00%> (+2.33%)	⬆️
unit-tests	51.65% <100.00%> (?)
unit-tests-macos-latest	?
unit-tests-ubuntu-latest	?
unit-tests-windows-latest	?

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[gauron99]

/lgtm
/hold @lkingland sorry didnt realize ports can be added to the name! thanks.

[knative-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: gauron99, lkingland

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[matejvasek]

Couldn't we implement isDigested() as

func isDigested(v string) (validDigest bool, err error) {
        ref, err := name.ParseReference(v)
        if err != nil {
	        return false, err
        }
        _, ok := ref.(name.Digest)
        return ok, nil
}

or

func isDigested(v string) (validDigest bool, err error) {
        ref, err := reference.Parse(v)
        if err != nil {
	        return false, err
        }
        _, ok := ref.(reference.Digested)
        return ok, nil
}

?

[lkingland]

Couldn't we implement isDigested() as

func isDigested(v string) (validDigest bool, err error) {
        ref, err := name.ParseReference(v)

Yes, I prefer this; using an extant implementation when available.

[matejvasek]

/lgtm