buildkite agent with a side of Docker

docker-compose.yml

version: "3.3"

volumes:
  shared: {}

services:

  docker:
    image: docker:rc-dind
    privileged: true
    userns_mode: host
    volumes:
      - shared:/shared
  
  agent:
    image: buildkite/agent:3.0
    depends_on:
    - docker
    environment:
      DOCKER_HOST: tcp://docker:2375
    command: bash
    entrypoint: []
    volumes:
      - shared:/shared