Creating a persistent local registry with S3/MinIO¶

The network design is

MinIO running on a separate host (replicating AWS s3)
docker registry hosted as a service through docker swarm

Table of Contents¶

Configurations
Starting the registry service

Configurations¶

We will use Docker Configs as a convenient way of handling configuration files over the raft architecture of swarm.

The registry configuration documentation can be found here. A possibly configuration for our aim could be:

# registry-config.yml
version: 0.1
log:
  fields:
    service: registry
    environment: staging

storage:
  # allow in-memory caching
  cache:
    blobdescriptor: inmemory
  s3:
    accesskey: [accessKey]
    secretkey: [secretAccessKey]
    region: eu-west-1
    regionendpoint: http://[endpoint]:9000
    bucket: docker
    encrypt: false

    # no https
    secure: false
    skipverify: true

    # upload 5 MB chunks (minimum size)
    chunksize: 5242880

    # directory of bucket to use
    rootdirectory: /
  delete:
    enabled: true

http:
  addr: :5000
  headers:
    X-Content-Type-Options: [nosniff]
health:
  storagedriver:
    enabled: true
    interval: 10s
    threshold: 3

Where we have configured an S3 type storage for the docker registry repositories.

For the S3 configuration reference, see the storage driver docs.

We then create a Docker Config with

docker config create registry /path/to/registry-config.yml

As far as I can tell, to update the configuration, you have to remove the config

docker config rm registry

and then create it again with the updated file. There doesn’t seem to be an update command, like with managing services, despite configs only being usable for services.

Starting the registry service¶

As documented in another of my notes on Docker Swarm, we can deploy a registry service with

docker service create -p 5000:5000 -d \
  --name registry \
  registry:2

however to register our configuration file, we need to use a syntax provided in the docker examples, and modify our service with

docker service create -p 5000:5000 -d \
  --name registry \
  --config src=registry,target="/etc/docker/registry/config.yml" \
  registry:2

Inspect the logs with

docker service logs registry

to make sure everything is healthy. We can then push an image to our local registry

docker push [endpoint]:5000/some-image

check that it uploaded successfully with

curl [endpoint]:5000/v2/_catalog

and view it in our storage bucket under /docker.