Session handling in mean stack - node.js

I am new to MEAN stack, presently the mean stack is inserting sessions to mongodb:
app.use(session({
saveUninitialized: true,
resave: true,
//cookie: { maxAge: 600 },
secret: config.sessionSecret,
store: newmongoStore({
db: db.connection.db,
collection: config.sessionCollection
})
}));
But I want to save some custom variables in that session & access them across requests, I did not get how to save it in session. Let's say I want to save mydata in session, I saw some examples & tried like:
req.session.mydata = 'projectdata';
req.session.cookie.mydata = 'projectdata';
Both are not working. Also I want to update maxAge variable on every request to server side, how to do it? Kindly help me.

Better use Token based sessions, It will help you making you API universal ie, You can also use the same API for mobile applications.
Try implementing Token Based Authentication using psJwt.
You will find good articles for this on scotch.io and on Plural sight.

Related

how to check session store used by node application

Currently, I have a node application where I need to check the specific session store I am using to manage store session variables. I never explicitly configured this (though someone else working on the same codebase could have) and haven't been able to find anything specific, and I need to know if the session store uses the touch method to know if I should set the resave proprty of sessions to true or false.
First of all, you need to locate the express-session usage in your code base.
Should be in your server.js or app.js file. Being used as
app.use(session({...properties}));
For example it may look like this:
app.use(session({
saveUninitialized: true,
resave: true,
secret: 'secret-123',
cookie: { secure: false, httpOnly: true, maxAge: 60000 },
store: new CouchbaseStore({
db: connectionObj,
prefix: 'test'
})
}));
the default store is the Memory of the server. So you can override the store with connect-mongo, connect-couchbase, connect-redis and what not.

Understanding Express session in NodejS

I was trying to comprehend express-session from the docs and I am unable to get some points
Consider this code, which I found from a repo
app.use(session({
resave: true,
saveUninitialized: true,
secret: 'aaabbbccc',
store: new MongoStore({
url: MONGO_URI,
autoReconnect: true
})
}));
Now, I probably get what is happening here but still just to confirm
resave: true according to the doc will mean that it will force to save session back to the session even if it hasn't changed. Okay Cool? But why would someone force to save a session when it isn't changed and what difference will make it make?
saveUninitialized: true Here we are storing the session for non-logged in user as well?
And Finally if someone could explain this line of code as well (which I am unable to comprehend)
store: new MongoStore({
url: MONGO_URI,
autoReconnect: true
})
Moving on, In the above code, the author of the repo isn't storing the session in the cookie? and is just storing the cookie identifer?
And lastly, In the description they have mentioned/talked about cookie.httpOnly, cookie.expires and cookie.domain
Now, I understood their functionality but am unable comprehend their implemention, so if anyone could showcase implementation for any one of them?
These are my understandings. I might be wrong.
May be resave is used for certain storage driver to keep session alive!? I don't have anything in mind right now.
saveUninitialized is true means, a session will always be created. Experiment: Create a simple express server. Configure express-session and keep that value true. Don't create any session manually. Hit any endpoint of your server from browser. Open developer options and look for cookies. You will see a cookie has generated. Now, remove the cookie. Change the value to false and hit the endpoint again. No cookie will generate this time.
If you don't mention any store then all sessions will be stored in MemoryStore which is build only for development purpose. So in production you should always use some sort of persistent storage. There are a good numbers of storage options available.

Flash messages for REST API

I want to build REST API using Express. Aside from resources there are endpoints for authentication stuff like signup, signin and user option (the view templates are loaded). It's common practice to use sessions for messages but how can I handle this for REST API? IS it okay to use for example express-session for flash messages only or I need to resolve this without session?
Yes you can use express-session.
However you should not that if you wish to use this in production you'll need to setup a database of sort to store these sessions as it is not recommended to use the default in-memory storage solution.
As for the REST API part, just make sure that you call:
app.use(session({
secret: 'keyboard cat',
resave: false,
saveUninitialized: true,
cookie: { secure: true }
}))
Before you add your routes to the app. This way the session will be activated for all REST API calls. You can see a nice blog / example here which should help guide you through it.

Saving session data across multiple node instances

EDIT - Oct 22, 2017
There was more than one reason our sessions weren't persisting, I've had to change ourexpress-session options to this:
api.use(session({
secret: 'verysecretsecret',
resave: false,
saveUninitialized: false,
cookie: {
path: '/',
httpOnly: true,
domain: 'domain.dev',
maxAge: 1000 * 60 * 24
},
store: new MongoStore({ mongooseConnection: mongoose.connection, autoReconnect: true })
}));
Apparently domain: 'localhost' causes express-session to start a new session every single time someone starts a session and then refreshes/navigates away and back when you have a seperate node instance for session handling.
I've solved this issue by doing the following:
Added 127.0.0.1 domain.dev to my hosts file located in C:\Windows\System32\drivers\etc.
I needed a place to store sessions as per the answers given below, so we chose MongoDB. This meant I had to add the following to my express-session options:store: new MongoStore({ mongooseConnection: mongoose.connection, autoReconnect: true })
Added the httpOnly: true property to the express-session options.
Because we use jQuery for our ajax requests, I had to enable some settings in the front-end web app before making calls to the back-end:$.ajaxSetup({
xhrFields: { withCredentials: true },
crossDomain: true,
});
ORIGINAL POST
I'm currently working on a platform for which was decided to have the API running on port 3001 whilst the web application itself is running on port 3000. This decision was made to make monitoring traffic more easy.
Now, we're talking about express applications so we defaulted to using the express-session npm package. I was wondering if it's at all possible to save session data stored on the node instance running on port 3001 and be retrieved by the node instance running on port 3000 if that makes sense.
To elaborate, this is our user authentication flow:
User navigates to our web app running on port 3000.
User then signs in which sends a POST request to the API running on port 3001, session data is stored when the credentials are correct, response is sent so the web app knows the user is authenticated.
User refreshes the page or comes back to the web app after closing their browser so web app loses authenticated state. So on load it always sends a GET request to the API on port 3001 to check if there's session data available, which would mean that user is logged in, so we can let the web app know user is authenticated.
(If my train of thought is at fault here, please let me know)
The problem is that express-session doesn't seem to be working when doing this.
I've enabled CORS so the web app is able to send requests to the API. And this is what the express-session configuration looks like:
api.use(session({
secret: 'verysecretsecret',
resave: false,
saveUninitialized: false,
cookie: {
path: '/',
domain: 'localhost',
maxAge: 1000 * 60 * 24
}
}));
Preferably help me solve this problem without using something like Redis, I'd simply like to know if solving this problem is possible using just express-session and node.
Preferably help me solve this problem without using something like Redis
You want us to help you solve this problem preferably without using the right tool for the job.
Without Redis you will need to use some other database. Without "something like Redis" (i.e. without a database) you will need to implement some other way to handle something that is a book example use case for a database.
And if you're going to use a database then using a database like Redis or Memcached is most reasonable for the sort of things where you need fast access to the data on pretty much every request. If you use a slower database than that, your application's performance will suffer tremendously.
I'd simply like to know if solving this problem is possible using just express-session and node.
Yes. Especially when you use express-session with Redis, as is advised in the documentation of express-session module:
https://github.com/expressjs/session#session-store-implementation
If all of your instances work on the same machine then you may be able to use a database like SQLite that stores the data in the filesystem, but even when all of your instances are on the same box, my advice would be still to use Redis as it will be much simpler and more performant, and in the case when you need to scale out it will be very easy to do.
Also if all of your session data can fit in a cookie without problems, then you can use this module:
https://www.npmjs.com/package/cookie-session
that would store all of the session data in a cookie. (Thanks to Robert Klep for pointing it out in the comments.)

My Node.js web app establishes new session every time I reopen the browser

Every time I close all the browser windows and then open the web app again, a new session is established, that means I have to authenticate again.
For your reference, I use express#4.14.0 as the web application framework, express-session#1.14.1 + connect-mongo#1.3.2 as middleware to store the sessions and passport#0.3.2 for authentication.
Below is the code for cookie and session configuration:
// CookieParser should be above session
app.use(cookieParser());
// Express MongoDB session storage
app.use(session({
resave: true,
saveUninitialized: true,
name: config.sessionName,
secret: config.sessionSecret,
store: new MongoStore({
mongooseConnection: db.connection,
collection: config.sessionCollection
})
}));
The "old" session stored in MongoDB still has two weeks to expire.
It seems like the Node.js application cannot recognize the "old" session from browser, therefore create a "new" one and tell the browser to use the "new" one.
It does not happen occasionally, but always, so I believe there is something wrong in my web application.
Thanks to #Bradley, finally I figured out what's wrong.
This is my solution
app.use(session({
cookie: {
maxAge: ms('14 days') // `ms` is a node module to convert string into milliseconds
},
resave: true,
saveUninitialized: true,
name: config.sessionName,
secret: config.sessionSecret,
store: new MongoStore({
mongooseConnection: db.connection,
collection: config.sessionCollection
})
}));
For more information, please refer to https://github.com/expressjs/session#expires
By default, no expiration is set, and most clients will consider this a "non-persistent cookie" and will delete it on a condition like exiting a web browser application.
That's why I encountered this problem.

Resources