aptly/server/mirror/ubuntu/xenial/docker.yml

parameters:
  _param:
    mirror_docker-xenial_source: 'https://download.docker.com/linux/ubuntu'
    mirror_docker-xenial_distribution: xenial
    mirror_docker-xenial_components: stable
    mirror_docker-xenial_gpgkeys:
      - 9DC858229FC7DD38854AE2D88D81803C0EBFCD88
  aptly:
    server:
      mirror:
        docker-xenial:
          source: ${_param:mirror_docker-xenial_source}
          distribution: ${_param:mirror_docker-xenial_distribution}
          components: ${_param:mirror_docker-xenial_components}
          architectures: amd64
          gpgkeys: ${_param:mirror_docker-xenial_gpgkeys}
          publisher:
            component: docker
            distributions:
              - ubuntu-xenial/${_param:apt_mk_version}