Poor Man Registry

A poor man's registry that redirect to Chainguard's container registry.

Motivation

• The public, free tier of Chainguard Images only serves latest tag. This could be of inconvenience so we build this to continously watching Chainguard registry for digest changes and extract the package version via SBOM. We then tag the image according with the packaged software version and serve via this proxy.

Usage

go run main.go server --config=config.yaml

How it works

sequenceDiagram
autonumber
actor U as User
participant RR as Proxy
participant DB as Local Digest Database
participant CG as Chainguard Images
U->>+RR: Pull command `nginx:1.0.0`
RR->>+DB: Check if digest existed for `nginx:1.0.0`
DB-->>-RR: Found digest for `nginx:1.0.0`
RR-->>-U: Return digest if found

loop Every x Minutes
RR->>CG: Periodically checking `latest` tag for digest change
RR->>DB: Save digest for this tag to local db
end


RR->>CG: Proxied every other APIs