Cookies handling when client-side is also an ExpressJS app - node.js

Question

As far as I'm concerned, for a server side application to know what clients are communicating with it, it will save a cookie in the client with the session ID.
That is indeed what express-session a popular package for session storage in ExpressJS says in the documentation
Note Session data is not saved in the cookie itself, just the session ID. Session data is stored server-side.
So I believe I can assume this is strategy used by Express to maintain user data in sessions as well.
I did something else: I'm using Redis to store the Session data in my ExpressJS server app.
So having said that, my problem is that my client application is also an Express app. I have a nodejs app with Express both for client and server. There is a SPA involved in this problem, but it communicates with the 'express client' so it appears to be a different problem.
So everytime I send a request from Express Client to Express Server, there is not cookie being passed, so it can't identify a session ID and creates a new one, generating lots of garbage in Redis and making the session solution useless.
How should I save or fake a cookie in the Express Client app, or, even better, how this kind of problem is solved?
Actually if I knew what the Express Server is expecting in the request (a cookie, a header or whatever) I think I can solve the problem.
Anyone know what to do?
#Solved
Alright, so, in my nodejs client application I did the following:
login(req,res,next){
var options = {
url : 'http://localhost:8090/user/login_handler';
};
request(options, function(error,response,body) {
var cookie_string = response['headers']['set-cookie'][0].split(';')[0];
req.session.cookie_string = cookie_string;
});
}
check(req,res,next){
var options = {
url : 'http://localhost:8090/user/check_handler',
headers: {
'cookie':req.session.cookie_string
}
};
request(options, function(error,response,body){
res.json( body);
});
}
In short, when the session is created in the server side, it will respond with headers to tell the client to create a cookie. I save the important information to pass as a cookie in a different moment. The server-side then read the headers in the middleware and load the correect data to the session.

Answer 1

Without knowing the details of your architecture I would guess that what you want is to either set the saveUnitialized option to false, and not save the extraneous sessions, or only apply the express-session middleware to certain routes in your "Express Server" application