Unleash awesomeness. Private packages, team management tools, and powerful integrations. Get started with npm Orgs »

moleculer-io

0.13.4 • Public • Published

LOGO GitHub license npm

Moleculer-io

The moleculer-io is the API gateway service for Moleculer using socket.io. Use it to publish your services.

Features

  • Call moleculer actions by emiting Socket.io events.
  • Support Socket.io authorization (Default: socket.client.user => moleculer ctx.meta.user)
  • Whitelist.
  • Middlewares.
  • Broadcast events.
  • Joining and leaving rooms.

Install

$ npm install moleculer-io

Usage

Init server

Using with Node http server:

const server = require('http').Server(app)
const SocketIOService = require("moleculer-io")
const ioService = broker.createService({
  name: 'io',
  mixins: [SocketIOService]
})
 
ioService.initServer(server)
// Once the initServer() was called, you can access the io object from ioService.io
broker.start()
server.listen(3000)

Or let moleculer-io create a server for you:

const ioService = broker.createService({
  name: 'io',
  mixins: [SocketIOService]
})
ioService.initServer(3000)
broker.start()

More simple:

broker.createService({
  name: 'io',
  mixins: [SocketIOService],
  settings:{
    port:3000 //will call initServer() on broker.start()
  }
})
broker.start()

Or maybe you want to use it with moleculer-web

const ApiService = require("moleculer-web");
const SocketIOService = require("moleculer-io")
broker.createService({
  name: 'gw',
  mixins: [ApiService,SocketIOService], //Should after moleculer-web
    settings: {
        port: 3000
    }
})
broker.start()

moleculer-io will use the server created by moleculer-web automatically.

Handle socket events

Server:

const IO = require('socket.io')
const { ServiceBroker } = require('moleculer')
const SocketIOService = require('moleculer-io')
 
const broker = new ServiceBroker({
  logger: console,
  metrics:true,
  validation: true
})
 
broker.createService({
    name: "math",
    actions: {
        add(ctx) {
            return Number(ctx.params.a) + Number(ctx.params.b);
        }
    }
})
 
const ioService = broker.createService({
  name: 'io',
  mixins: [SocketIOService],
  settings: {
    port: 3000
  }
})
 
broker.start()

By default, moleculer-io handle the call event which will proxy to moleculer's broker.call

Examples:

  • Call test.hello action without params: socket.emit('call','test.hello', callback)
  • Call math.add action with params: socket.emit('call','math.add', {a:25, b:13}, callback)
  • Get health info of node: socket.emit('call','$node.health', callback)
  • List all actions: socket.emit('call', '$node.list', callback)

Example client:

const io = require('socket.io-client')
const socket = io('http://localhost:3000')
socket.emit('call','math.add',{a:123, b:456},function(err,res){
  if(err){
    console.error(err)
  }else{
    console.log('call success:', res)
  }
})

Handle multiple events

You can create multiple routes with different whitelist, calling options & authorization.

broker.createService({
  name: 'io',
  mixins: [SocketIOService],
  settings: {
    port: 3000,
    namespaces: {
      '/':{
        events: {
          'call':{
            whitelist: [
              'math.add'
            ],
            callOptions: {}
          },
          'adminCall': {
            whitelist: [
              'users.*',
              '$node.*'
            ]
          }
        }
      }
    }
  }
})

Custom handler

You can make use of custom functions within the declaration of event handler.

broker.createService({
  name:'io',
  mixins: [SocketIOService],
  settings: {
    port:3000,
    namespaces: {
      '/':{
        events:{
          'call':{},
          'myCustomEventHandler': function(data, ack){ // write your handler function here.
            let socket = this
            socket.emit('hello', 'world')
                        socket.$service.broker.call('math.add', { a:123, b:456 })
          }
        }
      }
    }
  }
})

There is an internal pointer in socket objects:

  • socket.$service is pointed to this service instance.

Handler hooks

The event handler has before & after call hooks. You can use it to set ctx.meta, access socket object or modify the response data.

broker.createService({
  name: 'io',
  mixins: [SocketIOService],
  settings: {
    namespaces: {
      '/':{
        events:{
          'call':{
            whitelist: [
              'math.*'
            ],
            before: async function(ctx, socket, args){ //before hook
              //args: An object includes { action, params, callOptions }
              console.log('before hook:', args)
            },
            after:async function(ctx, socket, res){ //after hook
              console.log('after hook', res)
              // res: The respose data.
            }
          }
        }
      }
    }
  }
})

Calling options

The handler has a callOptions property which is passed to broker.call. So you can set timeout, retryCount or fallbackResponse options for routes.

broker.createService({
  name: 'io',
  mixins: [SocketIOService],
  settings:{
    namespaces:{
      '/':{
        events:{
          'call':{
            callOptions:{
              timeout: 500,
              retryCount: 0,
              fallbackResponse(ctx, err) { ... }
            }
          }
        }
      }
    }
  }
})

Note: If you provie a meta field here, it replace the getMeta method's result.

Middlewares

Register middlewares. Both namespace middlewares and packet middlewares are supported.

broker.createService({
  name: 'io',
  mixins: [SocketIOService],
  settings:{
    namespaces: {
      '/': {
        middlewares:[ //Namespace level middlewares, equipment to namespace.use()
          function(socket, next) {
             if (socket.request.headers.cookie) return next();
             next(new Error('Authentication error'));
           }
        ],
        packetMiddlewares: [ // equipment to socket.use()
          function(packet, next) {
             if (packet.doge === true) return next();
             next(new Error('Not a doge error'));
           }
        ],
        events:{
          'call': {}
        }
      }
    }
  }
})

Note: In middlewares the this is always pointed to the Service instance.

Authorization

You can implement authorization. For this you need to add an handler.

broker.createService({
  name: 'io',
  mixins: [SocketIOService],
  settings: {
    namespaces: {
      '/':{
        events:{
          'call':{
            whitelist: [
              'math.*',
              'accounts.*'
            ]
          }
        }
      }
    }
  }
})
 
broker.createService({
  name: 'accounts',
  actions: {
    login(ctx){
      if(ctx.params.user == 'tiaod' && ctx.params.password == 'pass'){
        ctx.meta.user = {id:'tiaod'} // This will save to socket.client.user
      }
    },
    getUserInfo(ctx){
      return ctx.meta.user //Once user was logged in, you can get user here.
    }
  }
})

Client:

socket.emit('login', 'accounts.login', {user: 'tiaod', password: 'pass'}, function(err,res){
  if(err){
    alert(JSON.stringify(err))
  }else{
    console.log('Login success!')
  }
})

See examples/simple

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

getMeta(socket){
  return {
    user: socket.client.user,
    $rooms: Object.keys(socket.rooms)
  }
}

Example to add more additional info:

broker.createService({
  name:'io',
  mixins: [SocketIOService],
  methods:{
    getMeta(socket){ //construct the meta object.
      return {
        user: socket.client.user,
        $rooms: Object.keys(socket.rooms),
        socketId: socket.id
      }
    }
  }
})

By default, ctx.meta.user will save to socket.client.user, you can also overwrite it. The default saveUser method is:

saveUser(socket,ctx){
    socket.client.user = ctx.meta.user
}

Make authorization on connection

If you don't want to emit an event to login, you can use query to pass your token:

// server
broker.createService({
  name: 'io',
  mixins: [SocketIOService],
  settings: {
    namespaces: {
      '/': {
        middlewares: [
          async function(socket, next) {
            if (socket.handshake.query.token) {
              let token = socket.handshake.query.token
              try {
                let res = await this.broker.call("account.verifyToken", {
                  token
                })
                if (res.token) socket.emit('setToken', res.token) //Update your token
                socket.client.user = res.user
              } catch (e) {
                socket.emit('setToken', null) // verify failed, clear client token
                return next()
              }
            }
            next()
          }
        ]
      }
    }
  }
})
// client
let token = localStorage.getItem('myToken')
const socket = io(process.env.SERVER_ADDR, {
  query: token ? { token } : {}
})
 
socket.on('setToken', (token) => {
  // Save your token here
  if (token) {
    localStorage.setItem('myToken', token)
  } else {
    localStorage.removeItem('myToken')
  }
})
 
socket.on('reconnect_attempt', () => {
  let token = localStorage.getItem('myToken')
  if (token) {
    socket.io.opts.query.token = token
  } else {
    delete socket.io.opts.query.token
  }
})

Joining and leaving rooms

In your action, set ctx.meta.$join or ctx.meta.$leave to the rooms you want to join or leave.

eg.

ctx.meta.$join = 'room1' //Join room1
ctx.meta.$join = ['room1', 'room2'] // Join room1 and room2
 
ctx.meta.$leave = 'room1' //Leave room1
ctx.meta.$leave = ['room1', 'room2'] // Leave room1 and room2

After the action finished, moleculer-io will join or leave the room you specified.

Example room management service:

broker.createService({
  name: 'rooms',
  actions: {
    join(ctx){
      ctx.meta.$join = ctx.params.room
    },
    leave(ctx){
      ctx.meta.$leave = ctx.params.room
    },
    list(ctx){
      return ctx.meta.$rooms
    }
  }
})

Broadcast

If you want to broadcast event to socket.io from moleculer service:

broker.call('io.broadcast', {
  namespace:'/', //optional
  event:'hello',
  args: ['my', 'friends','!'], //optional
  volatile: true, //optional
  local: true, //optional
  rooms: ['room1', 'room2'] //optional
})

Note: You should change the 'io' to the service name you created.

Using multiple instances

If you plan for a highly available setup (launching multiple instances of this service behind a Load Balancer), you will have to take some extra steps. Due to the nature of WebSockets these instances will need a PubSub capable broker to connect to, in order to broadcast messages to sockets which are connected to other instances. For a more in depth explanation of this concept, and additional steps that have to be taken (such as Load Balancer configuration), refere to the Socket.io Documentation.

In order to interconnect this service with other services, start the service with an adapter:

broker.createService({
    name: 'io',
    mixins: [SocketIOService],
    settings:{
        port:3000, //will call initServer() on broker.start()
        adapter: {
            module: require("socket.io-redis"),
            options: {
                host: 'redis',
                port: 6379
            }
        }
    }
})

Full settings

settings:{
  port: 3000,
  io: {}, //socket.io options
  adapter: {
   module: require('socket.io-...') // socket.io adapter module
   options: {} // socket.io adapter options
  },
  namespaces: {
    '/':{
      middlewares:[],
      packetMiddlewares:[],
      events:{
        'call':{
          whitelist: [],
          callOptions:{},
          before: async function(ctx, socket, args){},
          after:async function(ctx, socket, res){}
        }
      }
    }
  }
}

Change logs

0.13.4: Fix bug of multiple custom event handler.

0.13.3: Add internal pointer to service instance, make socket.$service pointed to service instance.

0.13.2: Added socket.io adapter options for intercommunication of multiple instances

0.13.1: Add request logger.

0.13.0: moleculer-io can now get alone well with moleculer-web, you can use them together! - Note that settings.options now become to settings.io.

0.12.1: CustomHandler context now bind to the service instance.

0.12.0: Change ctx.meta.$user to ctx.meta.user, add saveUser method.

0.11.0: Bind middlewares context to service instance.

0.10.0: Add action visibility support. See Action visibility

0.9.1: Fix ServiceNotFoundError message.

0.9.0: Upgrade to moleculer@0.13, no breaking changes.

0.8.1: Fix io.broadcast error.

0.8.0: Add ctx.meta.$rooms, and ctx.meta.$join ctx.meta.$leave

0.7.0: Add hooks.

0.6.0: Modify settings format. again :)

0.5.0: Add broadcast to socket.io rooms

0.4.0: Modify settings format.

0.3.0: Add login handler.

0.2.0: Add initServer method.

License

Moleculer-io is available under the MIT license.

install

npm i moleculer-io

Downloadsweekly downloads

93

version

0.13.4

license

MIT

homepage

github.com

repository

Gitgithub

last publish

collaborators

  • avatar
Report a vulnerability