【session】

users.json

{
    "tobi": {
        "password": "ferret",
        "name": "Tobi Holowaychuk"
    }
}

session.js

var connect = require('connect')
var users = require('./users')

var server = connect(
    connect.logger('dev'),
    connect.bodyParser(),
    connect.cookieParser(),
    connect.session({secret: 'my app secret'}),
    function(req, res, next) {
        if ('/' == req.url && req.session.logged_in) {
            res.writeHead(200, {'Content-Type': 'text/html'})
            res.end('Welcome back, ' + req.session.name + '<a href="/logout">Logout</a>')
        } else {
            next()
        }
    },
    function(req, res, next) {
        if ('/' == req.url && 'GET' == req.method) {
            res.writeHead(200, {'Content-Type': 'text/html'})
            res.end([
                '<form action="/login" method="POST">',
                    '<input type="text" name="user">',
                    '<input type="password" name="password">',
                    '<button>Submit</button>',
                '</form>'
            ].join(''))
        } else {
            next()
        }
    },
    function(req, res, next) {
        if ('/login' == req.url && 'POST' == req.method) {
            res.writeHead(200)
            if (!users[req.body.user] || req.body.password != users[req.body.user].password) {
                res.end('Bad username/password')
            } else {
                req.session.logged_in = true
                req.session.name = users[req.body.user].name
                res.end('Authenticated!')
            }
        } else {
            next()
        }
    }, 
    function(req, res, next) {
        if ('/logout' == req.url) {
            req.session.logged_in = false
            res.writeHead(200)
            res.end('Logged out')
        } else {
            next()
        }
    }
)

server.listen(3000)