Enhance Multi-architecture Image Support

[Virviil]

Description

Improve existing partial multi-arch support with platform selection and better manifest handling, following Docker/skopeo patterns.

Current State

The tool can be run multiple times for different architectures, but lacks proper platform selection and multi-arch manifest handling.

Tasks

• Add --platform flag to select specific platform (e.g., --platform linux/amd64, --platform linux/arm64)
• Improve manifest parsing for multi-arch images
• Add platform detection and listing capabilities
• Better error handling for missing platforms
• Follow Docker/skopeo patterns for architecture selection
• Add tests for multi-arch scenarios

Skills Required

• Rust programming
• OCI spec knowledge, especially multi-arch manifests
• CLI design and argument parsing
• Container ecosystem understanding (Docker/skopeo patterns)

Technical Details

Platform Selection

Follow Docker's --platform flag pattern:

oci2git --platform linux/amd64 nginx:latest
oci2git --platform linux/arm64 nginx:latest

Manifest Handling

• Parse multi-arch manifest lists
• Handle platform-specific image selection
• Provide clear error messages for unavailable platforms

Reference Implementation

Study how Docker and skopeo handle platform selection:

• Docker: --platform flag
• Skopeo: --override-arch, --override-os, --override-variant

Files to Modify

• src/sources/ - Container engine integration
• CLI argument parsing - Add platform flag
• Manifest handling code
• Integration tests

Expected Impact

Users can easily work with multi-arch images without manual platform detection or multiple tool runs.

This is an advanced task perfect for Hacktoberfest! 🎃

Hacktoberfest 2025 🍂