Ignore size value from GetBlob

[cgwalters]

The internal API in containers/image returns a size...which is an int64 in the source probably because OCI Descriptor type have it be an int64 too for bad historical reasons; xref opencontainers/image-spec#153

Anyways, the GetBlob wrapper API returns -1 when the remote registry doesn't emit Content-Length: https://github.com/containers/container-libs/blob/3af9abd27f3b875122b9fedd88953e8c840d6958/image/docker/docker_client.go#L1068

And this apparently happens with at least the Quay mirror registry.

We also noticed this problem when adding GetRawBlob in containers/skopeo#2601
which simply doesn't return a size to the client at all.

[gemini-code-assist]

Summary of Changes

Hello @cgwalters, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request refines the handling of blob sizes returned by the GetBlob API. It ensures that potentially invalid or missing size information from remote registries (like -1 when Content-Length is absent) is safely disregarded, as the actual blob size is verified during a subsequent processing step. This change improves robustness when interacting with diverse registry behaviors.

Highlights

• Ignore GetBlob size value: Modified the GetBlob API call to explicitly ignore the returned blob length (bloblen), changing its type from u64 to serde_json::Value. This addresses cases where remote registries might return -1 for size (e.g., due to missing Content-Length headers), as the size is validated later in the FinishPipe.

Using Gemini Code Assist

The full guide for Gemini Code Assist can be found on our documentation page, here are some quick tips.

Invoking Gemini

You can request assistance from Gemini at any point in your pull request via creating an issue comment (i.e. comment on the pull request page) using either /gemini <command> or @gemini-code-assist <command>. Below is a summary of the supported commands.

Feature	Command	Description
Code Review	/gemini review	Performs a code review for the current pull request in its current state.
Pull Request Summary	/gemini summary	Provides a summary of the current pull request in its current state.
Comment	@gemini-code-assist	Responds in comments when explicitly tagged, both in issue comments and review comments.
Help	/gemini help	Displays a list of available commands.

Customization

To customize Gemini Code Assist for GitHub experience, repository maintainers can create a configuration file and/or provide a custom code review style guide (such as PEP-8 for Python) by creating and adding files to a .gemini/ folder in the base of the repository. Detailed instructions can be found here.

Limitations & Feedback

Gemini Code Assist may make mistakes. Please leave feedback on any instances where its feedback is incorrect or counter productive. You can react with 👍 and 👎 on @gemini-code-assist comments. If you're interested in giving your feedback about your experience with Gemini Code Assist for Github and other Google products, sign up here.

You can also get AI-powered code generation, chat, as well as code reviews directly in the IDE at no cost with the Gemini Code Assist IDE Extension.

Footnotes

1. Review the Privacy Notices, Generative AI Prohibited Use Policy, Terms of Service, and learn how to configure Gemini Code Assist in GitHub here. Gemini can make mistakes, so double check it and use code with caution. ↩

[gemini-code-assist]

Code Review

This pull request addresses a potential panic in get_blob when the remote registry returns a size of -1, which cannot be parsed as a u64. The fix involves changing the expected type to serde_json::Value and ignoring it, which is a sensible approach. My review includes a suggestion to use a more specific type than serde_json::Value to improve robustness.

[cgwalters]

This regression happened in a5f6ba7 for the record.