How to make Auth session with socket.io?

Generally I am a beginner and have no idea how to properly do auth in Ionic 2. I’m working on a private app which will be used inside our company for our own purposes.

Basically I have MySQL server with users (username:password) which need to log in in to the app and get some info from DB and also receive some messages. So for back-end i decided to use NodeJS with Socket.IO. Is there any tutorials on how I can handle this auth? I’m need some sort of session that all functions of the app would be available only after users auth…