Install docker-compose on CoreOS

cloud-config.yml

#cloud-config
# Uses the docker-compose alpine image 
# https://docs.docker.com/compose/install/#/install-as-a-container
coreos:
  units:
    - name: install-docker-compose.service
      command: start
      content: |
        [Unit]
        Description=Install docker-compose
        [Service]
        Type=oneshot
        ExecStart=/usr/bin/mkdir -p /opt/bin/
        ExecStart=/usr/bin/curl -o /opt/bin/docker-compose -sL https://github.com/docker/compose/releases/download/1.11.1/run.sh
        ExecStart=/usr/bin/chmod +x /opt/bin/docker-compose