non-root Docker

# /etc/docker/daemon.json
{
  "userns-remap": "docker"
}

#/etc/subuid
root:300000:65536
ubuntu:301000:65536
docker:231072:65536

#/etc/subgid
root:300000:65536
docker:231072:65536

docker network add --subnet 172.22.22.0/24

docker network add --subnet 172.22.20.0/24