README.md

For hosting a small CTF competition you can use a simple way to run the checksystem via docker compose on a single node.

If you want to have a more scalable and performance deploy you can look at the ansible scripts.

How to understand which node's configuration to use?

It depends on the quality of the checkers and their dependencies. In our experience the good checkers use minimum amount of CPU and RAM and utilize only network I/O.

We believe that the CTF competition for about 30 teams and 10 services can be deployed on single node with 32-48 dedicated modern CPU and 64 GB of RAM and 50 GB of SSD/NVMe local storage. Such configuration costs about 1.5$/hour in cloud providers.

You need a node with a fresh GNU/Linux (for example Debian or Ubuntu) and a fresh version of docker engine and docker compose.

Copy the docker-compose.yml and example of Dockerfile files on your node and create files cs.conf (by looking at the example in the repo and at the CONFIGURE.md) and .env like this:

POSTGRES_USER=postgres
POSTGRES_PASSWORD=Secr3t
POSTGRES_DB=cs
POSTGRES_URI=postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@pg/${POSTGRES_DB}
MOJO_LISTEN=http://0.0.0.0:8080

Don't forget about the checkers for the game. You must extend Dockerfile with you CTF's specific checkers and their denendencies. Also don't forget to add execute permission (chmod +x) to main files of the checkers.

And then start the checksystem via docker compose up -d and use web interface at http://localhost. By default, this deployment uses a modern scoreboard and you can still use original scoreboard at http://localhost/board.