User and channel tracing
That's a unique thing. The tracing feature of Centrifugo PRO allows attaching to any channel to see all messages flying towards subscribers or attach to a specific user ID to see all user-related events in real-time.
It's possible to attach to trace streams using Centrifugo admin UI panel or simply from terminal using CURL and admin token.
This can be super-useful for debugging issues, investigating application behavior, understanding that the application works as expected.
The tracing feature works fine for JSON messages. For binary payloads, there are some limitations currently.
Save to a file
It's possible to connect to the admin tracing endpoint with CURL using the admin session token. And then save tracing output to a file for later processing.
curl -X POST http://localhost:8000/admin/trace -H "Authorization: token <ADMIN_AUTH_TOKEN>" -d '{"type": "user", "entity": "56"}' -o trace.txt
Currently, you should copy the admin auth token from browser developer tools, this may be improved in the future.