Docker Registry on Cloudian S3

This guide shows how to create a local docker registry on internal Cloudian S3 Storage.

Create a s3-registry-config.yaml config file for docker registry such as the sample config file below.

• region, regionendpoint, v4auth, secure are critical values to be set exactly the same as the sample for it to work with Element's internal Cloudian S3.
• By setting rootdirectory to / it will store the data under the following path in S3 bucket: $bucket/docker/registry/v2/

version: 0.1
log:
  fields:
    service: registry
storage:
  s3:
    accesskey: **************************
    secretkey: **************************************************************
    region: region1
    regionendpoint: http://s3internal.servername
    bucket: dockerreg
    rootdirectory: /
    v4auth: true
    secure: false
  cache:
    blobdescriptor: inmemory
http:
  addr: :5000
  headers:
    X-Content-Type-Options: [nosniff]
health:
  storagedriver:
    enabled: true
    interval: 10s
    threshold: 3

start a registry container, note please run the following command from the path where the above configuration file located.

docker run -d -p 5000:5000 --restart=always --name registry -v `pwd`/s3-registry-config.yaml:/etc/docker/registry/config.yml registry:2

test the local docker registry

# Pull the ubuntu:16.04 image from Docker Hub.
docker pull ubuntu:16.04

# Tag the image as localhost:5000/my-ubuntu. This creates an additional tag for the existing image. When the 
# first part of the tag is a hostname and port, Docker interprets this as the location of a registry, when 
# pushing.
docker tag ubuntu:16.04 localhost:5000/my-ubuntu

# Push the image to the local registry running at localhost:5000:
docker push localhost:5000/my-ubuntu

# Remove the locally-cached ubuntu:16.04 and localhost:5000/my-ubuntu images, so that you can test pulling the # image from your registry. This does not remove the localhost:5000/my-ubuntu image from your registry.
docker image remove ubuntu:16.04
docker image remove localhost:5000/my-ubuntu

# Pull the localhost:5000/my-ubuntu image from your local registry.
docker pull localhost:5000/my-ubuntu

# Validate image data are in the local registry
aws s3 ls --recursive s3://dockerreg/ --endpoint-url http://s3internal.servername

• Deploy a registry server - https://docs.docker.com/registry/deploying/
• Configuring a registry - https://docs.docker.com/registry/configuration/#storage