server.js

var Syslog  = require('node-syslog');
Syslog.init("syslog-node",
            Syslog.LOG_PID | Syslog.LOG_ODELAY,
            Syslog.LOG_LOCAL0);

var net     = require('net');
var express = require('express');
var app     = express.createServer();
var io      = require('socket.io');
var mongodb = require('mongodb');
var MongoStore = require('connect-mongo');

var unixlib = require('unixlib');

var mongo_config = {host: 'localhost', port: 27017, db: 'syslog-node'};

var db = new mongodb.Db(mongo_config.db,
                        new mongodb.Server("127.0.0.1", 27017),
                        {native_parser:false});



var sessionStore = new MongoStore({db : mongo_config.db});

db.open(function(err, connection) {
    if (err) {
      console.log('*****************');
      console.log(err.stack);
      console.log('*****************');
      process.exit(1);
    }
    
    
    app.configure(function () {
        app.use(express.static(__dirname + '/public'));
        app.use(express.cookieParser());
        app.use(express.bodyParser());
        app.use(express.session({
              store: sessionStore,
                secret: 'secret', key: 'express.sid'
                }));
        app.use(app.router);
      }); 
    sio = io.listen(app);
    
    
    app.get('/', function(req, res){
        Syslog.log(Syslog.LOG_INFO, "Visit at '/'");
        res.render('index.ejs', {regex: req.session.regex || "",
              username : req.session.username,
              lines : req.session.lines || "100"});
      });
    
    app.post('/regex', function(req, res) {
        req.session.regex = req.body.regex;
        res.end();
      });
    
    app.post('/logout', function(req, res) {
        delete req.session.username;
        res.redirect(req.body.next);
      });
    
    app.get('/login', function(req, res) {
        res.render('login.ejs');
      });
    
    app.post('/login', function(req, res) {
        var next = "/login";
        var username = req.body.username;
        var password = req.body.password;

        unixlib.pamauth('chkpasswd', username, password, function(success) {
		if (success) {
		    req.session.username = req.body.username;
		    next = req.body.next;
		    console.log("Login worked");
		    res.redirect(next);
		} else {
		    console.log("Login Failed");
		    res.redirect(next);    
		}
	    });
	});
    
    var parseCookie = require('connect').utils.parseCookie;
    
    function last_n(regex, n, f) {
      connection.collection('logs', function(err, col) {
          s = {};
          if (regex) {
            s['message'] = {$regex : regex};
          }
          cur = col.find(s).sort({created_at : -1}).limit(n);
          f(cur);
        });
    }
    
    
    sio.sockets.on('connection', function(socket) {
        
        var regex = socket.handshake.regex;
        socket.set('regex', regex);
        
        function handle_result(cur) {
          var items = [];
          cur.each(function(err, item) {
              if (item) {
                items.unshift(item.message);
              } else {
                socket.emit('logs', items);
              }
            });
          
        }
        
        socket.on('get', function(args) {
            socket.get('regex', function (err, regex) {
                last_n(regex, args.lines, handle_result);
              });
          });
        
        socket.on('regex', function (regex) {
            socket.set('regex', regex);
          });

      });
    
    sio.set('authorization', function (data, accept) {
        // check if there's a cookie header
        if (data.headers.cookie) {
          // if there is, parse the cookie
          data.cookie = parseCookie(data.headers.cookie);
          // note that you will need to use the same key to grad the
          // session id, as you specified in the Express setup.
        data.sessionID = data.cookie['express.sid'];
        /// (literally) get the session data from the session store
        sessionStore.get(data.sessionID, function (err, session) {
            if (err || !session) {
              // if we cannot grab a session, turn down the connection
              accept(err.message, false);
            } else if(session.username) {
              data.regex = session.regex;
        accept(null, true);
            } else {
              accept("not logged in", false);
            }
          });
        
        } else {
          // if there isn't, turn down the connection with a message
          // and leave the function.
          return accept('No cookie transmitted.', false);
        }
      });
    
    app.listen(80);
    sio.set('log level', 1); 
    


    
    /* Syslog server */
    
    connection.collection('logs', function(err, col) {
        var i = [['created_at', -1]];
        col.ensureIndex(i, function(err, indexName) {
          });
      });
    
    function write_message (message) {
      connection.collection('logs', function(err, col) {
          col.insert({message : message,
                created_at : new Date()});
        });
    }
    
    var server = net.createServer(function (stream) {
        stream.setEncoding('utf8');
        stream.addListener("data", function (datagram) {
            var datas = datagram.split("\n");
            for (var data in datas) {
              data = datas[data];
              if (data.length == 0) {
                continue;
              }
              write_message(data);
              sockets = sio.sockets.sockets;
              for (var id in sockets) {
                var socket = sockets[id];
                socket.get('regex', function (err, regex) {
                    if (!regex || data.search(regex) != -1) {
                      socket.emit('logs', [data]);
                    }
                  });
                    }
            }
          });
      }); 
    server.listen(514, '0.0.0.0');
    /* ************* */
  });