pongo

CTF Session Manager Daemon (ctfsmd).

Table of contents

• Installation
  • Dependencies
  • Installation steps
• Firewall configuration
• Running/stopping pongo
• Logs with journalctl
• IP ranges expansion in Docker
  • Important considerations

Installation

Dependencies

1. Go +1.19
2. Docker:
   • Server: Docker Engine 20.10.18 (API 1.41)
   • Client: Docker Engine 20.10.18 (API 1.41)
3. (optional) Prometheus +2.38
4. (optional) Grafana +9.1.6

Installation steps

1. Check that the host system has all the required dependencies.
2. Run ./main_configuration.sh --install with sudo rights.
   • Take into consideration the IP ranges of Docker containers already running in the system (check this section for more details.).

Firewall configuration

If ufw is running in Ubuntu as a firewall, add the following rule to allow clients to access the HTTP website to acquire sessions:

$ ufw allow proto tcp from any to any port <PORT>

<PORT>: the port at which the service can be accessed.

Running/stopping pongo

• Start/stop daemon with systemctl

$ systemctl start pongo

$ systemctl stop pongo

Important notice: sometimes some of the containers of a session are not properly stopped when pongo is shut down. In that case, run docker ps -a to see which containers are still active, and stop the containers with docker stop. Finally, after all containers have been properly stopped, execute docker network prune -f to remove all unused Docker networks.

You can close all currently running Docker containers with the command: docker stop $(docker ps -q).

Logs with journalctl

In order to see the logs of the daemon use journalctl.

• See a periodically updated log of the most current events:

$ journalctl -f -t pongo

-f  : Show most current logs and update periodically.
-t  : Show only the logs of this particular service.

IP ranges expansion in Docker

• Copy the file daemon.json at /etc/docker/ on the Docker host to expand the range of available private IPs for all the containers running services, otherwise the session manager runs out of available IPs for the containers.
• Restart the Docker daemon afterwards, either with: systemctl restart docker, or systemctl reload docker or service docker restart.

Important considerations

• If a Docker daemon is already using part of the IP range declared on the new /etc/docker/daemon.json file, there will be an unsolvable conflict which will prevent the Docker daemon from correctly running.

• In order to fix this:

  a. Run route -n and check the current routing table in the system. If some current Docker containers are assigned to the IPs that you want to use, there will be a problem.

  b. Change the IP ranges declared on /etc/docker/daemon.json, so that they do not collide with the IP ranges of other already running Docker containers, as discovered in the previous step.