dnode-balancer (proof of concept)

 ________________
/                \
| dnode-balancer |
\______________  / ____       ___
               \| / .  \  .-´/   \`-.
                  \____ \/   \___/   \__
                       \_`---´___`---´-´
                        /../..\ /..\..\

• uses http-proxy to proxy requests
• provides a dnode-interface to set routes
• apps can connect to the dnode-interface and report for duty
• right now this runs with the new cluster-functionality of node

cli

for now only this works:

path/to/dnode-balancer/bin/cli.js start -p <balancerPort> \
                                        -h <balancerHost> \
                                        -P <dnodePort>    \
                                        -H <dnodeHost>

api

var db = require('dnode-balancer')
var config = {balancer:{port:9901},dnode:{port:9902}}

db(config,function(err){
  if (err) return console.log('something went wrong',err)
  console.log('balancer running on port '+config.balancer.port)
  console.log('dnode-interface running on port '+config.dnode.port)
  startApp()
})


// this is the app which tells the balancer to proxy requests

var http = require('http')
var dnode = require('dnode')
var port = Math.floor(Math.random() * 40000 + 10000)

function startApp() {
  http.createServer(function(req,res){
    res.end('hello world!')
  }).listen(port,function(){
    console.log('http-server running on port '+port)
    var opts = { port      : config.dnode.port 
               , reconnect : 500  
               }
    dnode().connect(opts,function(remote,conn){
      var proxyToThisApp =
        { route     : 'foo.bar.com'
        , host      : 'localhost'
        , port      : port
        , weight    : 10   // 1..10 (more weight = more requests)
        , permanent : true // if this is not set, the route will be deleted
                           // when this dnode-client disconnects
        }
      console.log('reporting for duty')
      remote.add(proxyToThisApp,function(err){
        if (err) return console.error('something went wrong!')
        console.log('dnode-balancer will proxy requests for me now')
      })
    })
  })
}

to try it out, copy the code from above and start it. then run curl http://localhost:9901/ -H "Host:foo.bar.com" - the output should be hello world!.