[agammann]

Summary

• Treat the colon in a registry host port separately from an image tag when adding an implicit :latest to Dockerfile parents.
• Resolve bashbrew children repository arguments that include a registry port or digest.

Reproduction

With FROM registry.example:5000/team/base, bashbrew from example previously printed the untagged reference and bashbrew children registry.example:5000/team/base failed to resolve the repository. The commands now use registry.example:5000/team/base:latest and identify the dependent image.

Verification

• go test -race ./... (Linux, Go 1.24.0)
• go vet ./pkg/dockerfile ./cmd/bashbrew (Linux, Go 1.24.0)
• Local manifest and Git fixture exercised both CLI commands before and after the fix.
• git diff --check

[tianon]

Nice, this seems solid/correct to me! Good catch!

I'm curious though, what's your use case? (This doesn't affect any of our builds or processes right now, as evidenced by it being an issue for years. 😂)

[agammann]

Thanks! This came from testing port-qualified registry references; I don't have an affected docker-library build to point to.

The case is an untagged base such as FROM registry.example:5000/team/base: bashbrew from leaves it untagged instead of adding :latest, and bashbrew children registry.example:5000/team/base misses the dependent image because it treats the host-port colon as a tag separator. That's the use case covered by the command-level reproductions and regression tests in this PR.

[tianon]

Yeah fair, thanks for sharing -- merging because it's correct (even though it doesn't affect us). 👍

I can't make any regression promises here, but hopefully the tests do well enough (they're the strongest evidence of correctness here ❤️)