events {
    worker_connections  1024;
}

http {

  upstream docker-registry {
    server registry:5000;
  }

  ## Set a variable to help us decide if we need to add the
  ## 'Docker-Distribution-Api-Version' header.
  ## The registry always sets this header.
  ## In the case of nginx performing auth, the header is unset
  ## since nginx is auth-ing before proxying.
  map $upstream_http_docker_distribution_api_version $docker_distribution_api_version {
    '' 'registry/2.0';
  }

  server {
    listen 80;

    # disable any limits to avoid HTTP 413 for large image uploads
    client_max_body_size 0;

    # required to avoid HTTP 411: see Issue #1486 (https://github.com/moby/moby/issues/1486)
    chunked_transfer_encoding on;

    location /v2/ {
        #auth_request /auth;

      # Do not allow connections from docker 1.5 and earlier
      # docker pre-1.6.0 did not properly set the user agent on ping, catch "Go *" user agents
      if ($http_user_agent ~ "^(docker\/1\.(3|4|5(?!\.[0-9]-dev))|Go ).*$" ) {
        return 404;
      }

      ## If $docker_distribution_api_version is empty, the header is not added.
      ## See the map directive above where this variable is defined.
      add_header 'Docker-Distribution-Api-Version' $docker_distribution_api_version always;

      proxy_pass                          http://registry:5000;
      proxy_set_header  Host              $http_host;   # required for docker client's sake
      proxy_set_header  X-Real-IP         $remote_addr; # pass on real client's IP
      proxy_set_header  X-Forwarded-For   $proxy_add_x_forwarded_for;
      proxy_set_header  X-Forwarded-Proto $scheme;
      proxy_read_timeout                  900;
    }
  }
}