Flatcar Container Linux config snippet to run container at boot

config.json

{"ignition":{"config":{},"security":{"tls":{}},"timeouts":{},"version":"2.3.0"},"networkd":{},"passwd":{},"storage":{},"systemd":{"units":[{"contents":"[Unit]\nAfter=docker.service\nRequires=docker.service\n\n[Service]\nRestart=always\nTimeoutStartSec=0\nExecStartPre=-/usr/bin/docker rm --force nginx\nExecStart=/usr/bin/docker run --rm --pull always --name nginx -p 80:80 nginx\nExecStop=-/usr/bin/docker stop nginx\n\n[Install]\nWantedBy=default.target\n","enabled":true,"name":"container.service"}]}}

config.yaml

systemd:
  units:
  - name: container.service
    enabled: true
    contents: |
      [Unit]
      After=docker.service
      Requires=docker.service

      [Service]
      Restart=always
      TimeoutStartSec=0
      ExecStartPre=-/usr/bin/docker rm --force nginx
      ExecStart=/usr/bin/docker run --rm --pull always --name nginx -p 80:80 nginx
      ExecStop=-/usr/bin/docker stop nginx

      [Install]
      WantedBy=default.target