Container Image Registry
An image registry stores and distributes container images, supporting version tags, layered caching, and access control.
Purpose
Centrally store and distribute container images, supporting CI/CD pull and push.
Mechanism
Images are identified by name:tag and stored in layers (union filesystem). push uploads images, pull downloads them. Docker Hub is the public registry; ECR/GCR/ACR are private ones. Harbor, an open-source private registry, adds image scanning and signing.
Use cases
- Image distribution
- CI/CD
- Private registries