Design a Container Image Registry

Problem

Design a container image registry (Docker Hub-style) that stores and serves image layers.

Requirements

Functional:

• Push/pull images by name:tag
• Content-addressed layer storage with dedup
• Manifest resolution
• Auth and rate limiting

Non-functional:

• Millions of pulls/day, large layers
• Dedup to save storage
• Global low-latency pulls

Discussion points

1. Content-addressed (digest) layer storage + dedup
2. Manifest and tag resolution
3. CDN for layer distribution
4. Auth, quotas, and rate limiting
5. Garbage collection of unreferenced layers