Private Docker Repository

The normal way to setup a private Docker repository is to simply use the container which has it all setup. This works really well for a lot of cases. I recently deployed a private repo where I need an implementation that was a bit easier to manage with existing tooling and infrastructure. Basically, this meant not running docker for the repo and integration with an existing authentication framework.

Instructions are CentOS 7 specific, but shouldn't be too hard to map to your distribution of choice.

nginx is used as a proxy to terminate TLS and handle the federated authentication, leaving the docker repository service running on localhost only.

Install

Repos: CentOS Extras, Docker-CE, (possibly EPEL)
Packages: docker-distribution, docker-ce, nginx

Configure

docker-distribution

I only customized the rootdirectory and http addr. See Docker's documentation.
/etc/docker-distribution/registry/config.yml (select parts)

version: 0.1
log:
  fields:
    service: registry
storage:
  cache:
    layerinfo: inmemory
  filesystem:
     rootdirectory: /path/to/storage/repo
http:
   addr: localhost:5000

nginx

(Not including SSL and federated authentication)

/etc/nginx/conf.d/docker.conf

server {
   server_name myrepo.mydomain;
   listen 443 ssl;
   # omit SSL directives here
   client_max_body_size 0;
   # This just has a simple HTML info page
   root /path/to/storage/docroot;
   index index.html;
   # proxy docker API
   location /v2 {
      proxy_set_header X-Forwarded-Host $host;
      proxy_set_header X-Forwarded-Server $host;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header X-Forwarded-Proto $scheme;
      proxy_set_header Host myrepo.mydomain;
      proxy_pass http://localhost:5000;
   }
}

docker

(This is optional. I use it to do local admin and some maintenance scripts.

/etc/docker/daemon.json

{
   "data-root": "/path/to/storage/root"
}

Run and Test

docker-distribution

systemctl start docker-distribution
systemctl enable docker-distribution

Verify

curl http://localhost:5000/v2/_catalog

Should return an empty repository list

{
   "repositories": []
}

nginx

systemctl start nginx
systemctl enable nginx

Verify

curl https://myrepo.mydomain/

Should return whatever you put at /path/to/storage/docroot/index.html

curl https://myrepo.mydomain/v2/_catalog

Should return an empty repository list

{
   "repositories": []
}

docker

systemctl start docker
systemctl enable docker

Verify

docker info

Should return some information about your docker installation (including the customized root path).

---

You have now setup a local Docker repository which will work just like the docker container based one.