- 
When a server is not specified, images are pushed and pulled from index.docker.io. 
 
- 
To qualify your image name, create a private repository without authentication.
 
- 
To configure authentication for a private registry, add the following code to the manifest file, depending on what version of Docker you are running. 
 
- 
If you are using Docker V1.10 or earlier, specify the docker version in the manifest file:
 
docker::registry { 'example.docker.io:5000':
  username => 'user',
  password => 'secret',
  email    => 'user@example.com',
  version  => '<docker_version>'
}
docker::registry {'https://index.docker.io/v1 ':
  username => 'username',
  password => 'password',
}