correct way to write cookies from the server side

[vstoykov]

I would like to make my NodeBB forum to write a cookie when the

I found the function that is executed when user is logged in successfully: authenticationController.onSuccessfulLogin.

How to make this function also to write a cookie?

I tried to guess, but it did not work:

req.cookie('loggedin', '1');
res.cookie('loggedin', '1');

Also I would like this cookie to be removed when the user is not logged in.

I need this cookie in order to make another layer of caching (for non-logged in users) using Nginx and to test how it will work.

Is it possible this to be made by a plugin?