l2tp in docker

l2tp:
image: siomiz/softethervpn
ports:
- "500:500/udp"
- "4500:4500/udp"
- "1701:1701/tcp"
environment:
- PSK=my-pre-shared-key
- USERS=my-username:my-password
cap_add:
- NET_ADMIN
restart: always