Getting the current chat room ID
Interesting question,

my first point is that it is not clear how you wrote the Room module, but ideally, that module should do 2 things:


Provide the created room to complete
Provide a way to deal with failure


Then, I would expect in the top code to see something like this:

var Room = require('../models/database').Room

exports.create = function (req, res) {
    Room.create({
        room_name: req.body.roomName
    })
    .complete(function ( success, room ) {
        if( success )
            res.redirect('rooms/videochat/' + room.roomName + '/' + room.roomId );
        else
            res.redirect('cuteapologetickittenvideo/');
    });
};


You will notice that I also changed req.body.roomName -> room.room_name -> room.roomName which makes more sense to me. On a general note I find it bad practice to require room_name in your call to the constructor, but roomName in the request. I would suggest to stick to 1 convention (The JavaScript One) and use roomName everywhere. Then you could write

var Room = require('../models/database').Room

exports.create = function (req, res) {
    Room.create( req.body ).complete(function roomComplete( success, room ) {
        if( success )
            res.redirect('rooms/videochat/' + room.roomName + '/' + room.roomId );
        else
            res.redirect('cuteapologetickittenvideo/');
    });
};


For the Jade processing, you should be able to get room id and name from the matching on '/rooms/videochat/:roomName/:roomId'.

Same for the client side javascript, I would be more inclined to get this from the URL than from a field in the HTML.