index.js

var createDoorknob = require('doorknob/server')
var authSocket = require('auth-socket')
var multilevel = require('multilevel')
var websocket = require('websocket-stream')
var url = require('url')

module.exports = function(opts) {
  var server = createDoorknob(opts)
  
  return authSocket({ httpServer: server }, function onSocket(err, req, socket, head) {
    if (err && err !== 'not logged in') return console.error(err)
    else if (err && err === 'not logged in') var loggedOut = true
    var parsed = url.parse(req.url, true)
    var id = parsed.pathname.split('/')[1]
    var db = server.doorknob.db.sublevel(id)
    var ws = websocket(socket)
    var multiOpts = {}
    if (loggedOut) multiOpts = { access: accessControl }
    var multilevelServer = multilevel.server(db, multiOpts)
    ws.on('end', function() {
      multilevelServer.destroy()
    })
    ws.pipe(multilevelServer).pipe(ws)
    if (opts.verbose) {
      ws.on('data', function(op) {
        console.log(id, 'incoming', op.trim())
      })
      multilevelServer.on('data', function(op) {
        console.log(id, 'outgoing', op.trim())
      })
    }
  })

  function accessControl(user, db, method, args) {
    if (!user || user.name !== 'root') {
      //do not allow any write access
      if (/^put|^del|^batch|write/i.test(method)) {
        throw new Error('read-only access')
      }
    }
  }
}