moleculer-sc

moleculer-sc

A API Gateway service for Moleculer framework using SocketCluster

Features

• Proxy SocketCluster events to moleculer.
• Support SocketCluster authorization (socket.authToken => moleculer ctx.meta.user)
• Access control lists (Using node_acl)

Install

$ npm install --save moleculer-sc

Usage

Before you start, you have to create a SocketCluster project, and write the code in worker.js.

Handle socket events

Create your own SocketCluster Gateway service.

// SocketCluster worker.js
const SocketClusterService = require('moleculer-sc')
module.exports.run = function (worker) {
  broker.createService({
    name:'sc-gw',
    mixins:[SocketClusterService],
    settings:{
      worker, // Pass the sc worker to settings.
    }
  })
  broker.start()
}

Example events:

• Call test.hello action: socket.emit('test.hello',null, callback)
• Call math.add action with params: socket.emit('test.hello',{a:25, b:13}, callback)
• Get health info of node: socket.emit('$node.health',null, callback)
• List all actions: socket.emit('$node.list', null, callback)

Authorization

You can implement authorization. For this you have to do 1 things.

1. Define the authorization handler in SocketCluster.

Example authorization:

// Server code
// This is a slightly simplified version of what it might look
// like if you were using MySQL as a database.

socket.on('login', function (credentials, respond) {
  var passwordHash = sha256(credentials.password);

  var userQuery = 'SELECT * FROM Users WHERE username = ?';
  mySQLClient.query(userQuery, [credentials.username], function (err, rows) {
    var userRow = rows[0];
    var isValidLogin = userRow && userRow.password === passwordHash;
    if (isValidLogin) {
      respond();
      // This will give the client a token so that they won't
      // have to login again if they lose their connection
      // or revisit the app at a later time.
      socket.setAuthToken({username: credentials.username, channels: userRow.channels});
    } else {
      // Passing string as first argument indicates error
      respond('Login failed');
    }
  })
})

Also you can overwrite the getMeta method to add more addition meta info. The default getMeta method is:

getMeta(socket){
  return {
    user: socket.authToken
  }
}

Access control lists

You can also pass a node_acl instance to settings:

let acl = require('acl')
acl = new acl(new acl.memoryBackend())
acl.allow('admin', 'math', 'add') // allow admin to call math.add
acl.addUserRoles('user id here', 'admin')
module.exports.run = function (worker) {
  broker.createService({
    name:'sc-gw', // SocketCluster GateWay
    mixins:[SocketClusterService],
    settings:{
      acl, //Optional
      worker,
    }
  })
  broker.start()
}

By default, moleculer-sc will get the userId from socket.authToken.id for node_acl. The default getUserId method is:

getUserId(socket){
  if(socket.authToken && socket.authToken.id){
    return socket.authToken.id
  }
}

You can overwrite the getUserId method to get userId from other field:

broker.createService({
  name:'sc-gw', // SocketCluster GateWay
  mixins:[SocketClusterService],
  settings:{
    acl, //Optional
    worker,
  },
  methods:{
    getUserId(socket){ //scSocket
      return socket.authToken.username
    }
  }
})

Publish to scChannel

todo