Chapter 25 - Worked Answers

1. Registry port versus tag

The parser compares the last colon with the last slash. In registry.example.test:5000/team/atlas:v2, the port colon occurs before a slash, while the v2 colon occurs after the final slash. Registry becomes registry.example.test:5000, name team/atlas and tag v2. No network lookup is needed. The parser’s accepted digest/reference syntax is its own supported subset, not proof that the registry serves the artifact.

2. Synthetic digest scope

Syntactic acceptance does not establish that an image exists, that the caller can pull it, or that a trusted publisher signed it. It also does not establish vulnerability safety or a particular platform manifest. The test uses synthetic digest data only to exercise metadata/pinning decisions. An executable lab needs an available independently verified artifact and actual pull/inspection evidence; copying a repeated-character digest into a manifest would not meet that gate.

3. Parser-only resolution

ParserResolver.Resolve calls Parse without contacting a registry. A tag-only request therefore produces no digest, even when a real registry could resolve that tag. RequireDigest checks the resulting metadata and rejects it. A resolver interface and an injected fixed resolver test demonstrate extensibility and field flow, not a shipped remote adapter. Supply a real digest or separately implement/test a trusted remote resolver with authentication, platform selection and bounded errors.

4. Private pull evidence

Create a scoped robot credential without logging its password, reference its namespace-local ID in an ordinary service, and retain sanitized service/task IDs, requested/pinned image and actual Engine outcome. Verify that the same available digest reaches pull and create. Inspect only safe metadata and clean up exact run-owned resources. JobSpec lacks imagePullSecret and ListAssignedTasks takes an earlier Job branch without ordinary service auth/environment resolution, so this observation cannot certify private Job pulls by analogy.

These answers use chapter 25 and its scoped claim/execution records. Design changes remain proposals until separately implemented and tested.