moleculer-gundb

GunDB Gateway for MoleculerJS

Features

Install

npm install moleculer-gundb --save

Usage

Test

$ npm test

In development with watching

$ npm run ci

Contribution

Please send pull requests improving the usage and fixing bugs, improving documentation and providing better examples, or providing some testing, because these things are important.

License

The project is available under the MIT license.

Contact

Copyright (c) 2018 Fathym, Inc

• Moleculer-io
• Features
• Install
• Usage
  • Init server
  • Handle socket events
  • Handle multiple events
  • Custom handler
  • Handler hooks
  • Calling options
  • Middlewares
  • Authorization
    • Make authorization on connection
  • Joining and leaving rooms
  • Broadcast
  • Full settings
• Change logs
• License

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')
          }
        }
      }
    }
  }
})

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:

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 user = await this.broker.call("users.resolveToken", {
                  token
                })
								this.logger.info("Authenticated via JWT: ", user.username);
	              // Reduce user fields (it will be transferred to other nodes)
								socket.client.user = _.pick(user, ["_id", "username", "email", "image"]);
              } catch (err) {
                return next(new Error('Authentication error'));
              }
            }
            next()
          }
        ]
      }
    }
  }
})

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.

Full settings

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

Change logs

x.x.x: Add initServer method.

License

moleculer-gundb is available under the MIT license.