Running Coturn + Promethes + Grafana in Docker

1. Run $ docker compose up to start services.

2. Test CoTurn connection.
   Use Firefox, go to https://webrtc.github.io/samples/src/content/peerconnection/trickle-ice/.
   Type in

• STUN or TURN URI: turn:localhost:3478?transport=tcp
• username: hello
• password: world

Note: Chrome has some connection issue (error code 701).

3. Check Prometheus statistics.
   Go to http://localhost:9641/metrics. This pages shows the metrics of CoTurn server.
   It will export to Prometheus. Go to http://localhost:9090/graph and type in metrics in the previous link such as turn_traffic_sentb.