If you have your Node running
node --debug server.js
This gives me a port number xxxx, should I use this port number when starting Chrome?
using $ vagrant ssh -- -L 5858:127.0.0.1:5858
to ssh connect to VM. also this comment would start a proxy server on port 5858;
you could test using telnet 127.0.0.1 5858 to see if local proxy server started or not.
In VM, you can start node with command
$ node --debug-brk app.js
PS: there is no need to touch the vagrant file. Reference: Connecting WebStorm to a remote node.js debugging session.