A docker image to hold pwn challenges in ctf war

This image contains xinetd to provide remote access services for pwn challenges, and also contains tcpdump to dump network traffics into pcap file.

Notice:

1. we use a modified xinetd version from our team to restrict syscalls called by xinetd services. In order to use this feature, docker container must run with --privileged option. No more --privileged needed now.
2. This docker image will produce docker volume each you create container from it. Better specify one using -v your_dump_volume:/var/lib/tcpdump.

Please check Dockerfile.example

1. Please DO NOT use your own start CMD or entrypoint for this docker image. If you really need to change it, please check phusion/baseimage for more details.