Document how to run your own proxy registry

[castrojo]

For local dev and for people with multiple machines ... it'd be nice to be able to just run a proxy to cache stuff, ala apt-cache-ng back in the day!

https://tanzu.vmware.com/developer/guides/harbor-as-docker-proxy/

[castrojo]

Ok I got this from @p5 and I'm able to successfully cache pulls and other OCI artifacts, but it errors out on the signed images.

I'm pretty sure it's a configuration issue but I haven't had time to investigate, tossing my config in here.

jorge@trunks ~/registry % cat docker-compose.yml 
version: '3'
services:
  registry:
    image: registry:2
    ports:
      - "5000:5000"
    environment:
      REGISTRY_STORAGE_DELETE_ENABLED: "true"
      REGISTRY_LOG_LEVEL: "info"
      REGISTRY_PROXY_REMOTEURL: https://ghcr.io

[castrojo]

From discord:

Robert (p5): Not sure if/how to get it to work for multiple registries or homebrew, but the simplest thing I could get working is:

# /etc/containers/registries.conf.d/001-ghcr-cache.conf

[[registry]]
prefix = "ghcr.io"
location = "localhost:5000"
insecure = true

# /etc/containers/systemd/cache.container

[Unit]
Description=Container Image Cache
After=network-online.target

[Container]
Image=docker.io/library/registry:2
ContainerName=registry
PublishPort=5000:5000
Environment=REGISTRY_STORAGE_DELETE_ENABLED=true
Environment=REGISTRY_PROXY_REMOTEURL=https://ghcr.io
Volume=registry:/var/lib/registry

[Install]
WantedBy=multi-user.target default.target

[b-]

I posted these links in the discord but I’ll put them here, too, for posterity’s sake: https://developer.skao.int/en/latest/tools/containers/docker-proxy-cache.html#id16 they're using a different way of specifying the mirror here, so I wonder if this would help.

Also that site mentions using sonatype registry as a proxy as well, which looks interesting but also maybe kind of heavy. And I don’t think it’s completely FOSS.