Strategies for managing multi-architecture container images in GitHub Container Registry

[girishlade111]

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Our team is working on expanding our containerized microservices platform to support multiple architectures (amd64, arm64, and arm/v7) for improved performance and cost optimization across different deployment targets. We're using GitHub Container Registry (GHCR) as our primary registry and need guidance on best practices.

Current setup:

• Docker-based microservices deployed across AWS (x86) and AWS Graviton instances (ARM)
• GitHub Actions workflows for CI/CD
• Approximately 25 container images across different services
• Current images only support amd64 architecture

Challenges we're facing:

1. Build efficiency: Building images for multiple architectures significantly increases our CI/CD pipeline execution time. We're currently using matrix builds, but this approach duplicates much of the work.

2. Manifest management: We need to understand the best way to create and manage multi-arch manifests in GHCR. Should we use docker buildx with the --platform flag or create manifests separately?

3. Tagging strategy: What's the recommended tagging convention for multi-arch images? Should we use architecture-specific tags (e.g., myimage:1.0.0-amd64) or rely solely on manifest lists?

4. Cache optimization: How can we effectively leverage layer caching across different architecture builds to minimize rebuild times?

5. Testing strategy: How do you test multi-arch images in GitHub Actions when the runner architecture might not match the target architecture? Are there emulation concerns we should be aware of?

Questions:

• What's the recommended GitHub Actions workflow structure for building multi-architecture images efficiently?
• Are there GHCR-specific features or limitations we should know about when working with multi-arch manifests?
• How do you handle the scenario where one architecture build fails but others succeed?
• What are the storage and bandwidth cost implications of hosting multi-arch images?
• Are there any gotchas with pulling multi-arch images from GHCR in different environments (K8s clusters, Docker Swarm, etc.)?

Would appreciate insights from teams who have successfully implemented multi-architecture container strategies with GHCR!