Docker-vnc is a simple Docker image with ZNC and BitlBee installed and ready to go.
ZNC's webadmin is ready to go. Just point your browser at
https://ip.of.docker.container/ and login with user znc and password
mL3dBIqNm. Obviosly the first thing you should do before exposing
the container to the internet is change the password for the znc
user.