Setting up a Docker Hub registry mirror on a Synology NAS

_README.md

Instructions

• Save the docker-compose.yml and config.yml in the same directory on one of your volumes on the NAS.
• SSH in and use docker-compose up -d
• Test the mirror with curl --head http://NAS-IP:55000
• Start up docker daemons with the following option or put this in the daemon config file or copy into Docker for Mac/Windows settings. --registry-mirror=http://NAS-IP:55000
• Pull an image and then check that it is cached in your mirror with curl http://NAS-IP:55000/v2/_catalog
  • or check that a large image isn't slow after the first pull :)

Notes

• This is all based on https://docs.docker.com/registry/recipes/mirror/

config.yml

# This is the registry config file
# Config reference https://docs.docker.com/registry/configuration/ - see this if you want https

version: 0.1

# you might want to drop log level to just info once things are working 
log:
    level: debug
proxy:
    remoteurl: https://registry-1.docker.io
storage:
    filesystem:
        rootdirectory: /var/lib/registry
http:
    addr: 0.0.0.0:5000

docker-compose.yml

version: '2'

# I'm using port 55000 as 5000 is used by the NAS web UI
# Notice that a config.yml file is mapped into the container, save that next to this docker-compose.yml
services:
    hub-mirror:
        image: registry:2
        restart: unless-stopped
        ports:
            - 55000:5000
        volumes:
            - ./config.yml:/etc/docker/registry/config.yml
            - hub-mirror:/var/lib/registry

# I'm using a named volume to persist the registry cache independent of the container lifespan
volumes:
    hub-mirror: