pptpd

docker-compose.yml

pptpd:
  image: vimagick/pptpd
  volumes:
    - ./pptpd.conf:/etc/pptpd.conf
    - ./pptpd-options:/etc/ppp/pptpd-options
    - ./chap-secrets:/etc/ppp/chap-secrets
  privileged: true
  restart: always
  #net: host

server

$ docker-compose up -d

WARNING: YOU NEED TO REBOOT IF CONTAINER RESTARTED.

You must open the following ports:

To allow PPTP tunnel maintenance traffic, open 1723/tcp.
To allow PPTP tunneled data to pass through router, open Protocol 47.

firewall

If you use net: host for networking:

$ vim /etc/defautl/ufw
# DEFAULT_FORWARD_POLICY="ACCEPT"
$ ufw reload
$ ufw allow 1723
$ iptables -t nat -A POSTROUTING -s 192.168.127.0/24 -j MASQUERADE