mesg-pusher

MESG Service for Pusher ID: com.mesg.pusher

Contents

• Installation
  • MESG SDK
  • Deploy the Service
• Definitions
  • Tasks
    • trigger
    • triggerBatch
    • channels
    • channel

Installation

MESG SDK

This service requires MESG SDK to be installed first.

You can install MESG SDK by running the following command or follow the installation guide.

npm install -g mesg-cli

Deploy the Service

To deploy this service, go to this service page on the MESG Marketplace and click the button "get/buy this service".

Features

Currently able to use Pusher channels, channel, trigger and triggerBatch features from MESG.

Use case

MESG Applications on different servers communicating together over Pusher notifications.

Example

1. on MESG Application on a server A : use this MESG Service to send notifications over Pusher.

2. on MESG Application on a server B : listen to the notifications emitted by MESG Application on a server A over Pusher.

How to listen in a MESG Application

Install MESG and Pusher dependencies :

yarn add mesg-js pusher-js

Create a socket connection to listen and react to Pusher notifications :

// in a MESG Application
const { application } = require('mesg-js')
const mesg = application()
const Pusher = require('pusher-js')
const pusher = new Pusher('PUSHER_APP_KEY', { cluster: 'PUSHER_CLUSTER', forceTLS: true }) // replace with your credentials
const INSTANCE_HASH = await mesg.resolve('com.mesg.pusher')
const CHANNEL = 'some-channel'
const EVENT = 'some-event'
const CREDENTIALS = { appId: 'PUSHER_APP_ID', key: 'PUSHER_APP_KEY', secret: 'PUSHER_APP_SECRET' } // replace with your credentials
// subscribe to Pusher channel
const channel = pusher.subscribe(CHANNEL)
// on Pusher notification received
channel.bind(EVENT, data => {
  // example : launch MESG service trigger task
  mesg.executeTask({
    instanceHash: INSTANCE_HASH,
    taskKey: 'trigger',
    inputs: mesg.encodeData({ ...CREDENTIALS, channel: CHANNEL, event: EVENT, ...data })
  })
})

Environment variables

Instead of providing Pusher credentials or options on each request, these can be provided via command line arguments or .env file, as shown below in Integration tests.

As usual, user inputs always takes precedence on defined environment variables.

Name	Enviroment Variable
appId	PUSHER_APP_ID
cluster	PUSHER_CLUSTER
useTLS	PUSHER_USE_TLS
host	PUSHER_HOST
keepAlive	PUSHER_KEEP_ALIVE
key	PUSHER_APP_KEY
port	PUSHER_PORT
proxy	PUSHER_PROXY
secret	PUSHER_APP_SECRET
timeout	PUSHER_TIMEOUT

Integration tests

In order to launch them locally you will have to pass the environment variables along with your command, like so :

• via command line arguments :

  export PUSHER_APP_ID=... && export PUSHER_APP_KEY=... && export PUSHER_APP_SECRET=... && export PUSHER_CLUSTER=... && export MESG_ACCOUNT=... && export MESG_PASSPHRASE=... && yarn test

• via .env file :
  • file

    export PUSHER_APP_ID=...
    export PUSHER_APP_KEY=...
    export PUSHER_APP_SECRET=...
    export PUSHER_CLUSTER=...
    export MESG_ACCOUNT=...
    export MESG_PASSPHRASE=...
    

  • command

    source .env && yarn test

---

Definitions

Tasks

trigger

Task key: trigger

triggers an event on one or more channels

Inputs

Name	Key	Type	Description
appId	appId	String	optional Pusher application ID
key	key	String	optional Pusher application key
secret	secret	String	optional Pusher application secret key
useTLS	useTLS	Boolean	optional whether to encrypt notification, defaults to false
cluster	cluster	String	optional if `host` is present, it will override the `cluster` option
host	host	String	optional whether to use a different host, defaults to api.pusherapp.com
port	port	Number	optional whether to use a different port, defaults to 80 for unuseTLS and 443 for useTLS
proxy	proxy	String	optional URL to proxy the requests through
timeout	timeout	Number	optional timeout for all requests in milliseconds
keepAlive	keepAlive	Boolean	optional enables keep-alive, defaults to false
name	name	String	event name
data	data	Object	event data (maximum 10Kb)
channels	channels	Object	optional array of one or more channel names - limited to 100 channels
channel	channel	String	optional channel name if publishing to a single channel (can be used instead of channels)
socket_id	socket_id	Object	optional excludes the event from being sent to a specific connection

Outputs

Name	Key	Type	Description
message	message	String	a dummy 'sent' message

triggerBatch

Task key: triggerBatch

triggers multiple events in a single call (up to 10 per call on the multi-tenant clusters)

Inputs

Name	Key	Type	Description
appId	appId	String	optional Pusher application ID
key	key	String	optional Pusher application key
secret	secret	String	optional Pusher application secret key
useTLS	useTLS	Boolean	optional whether to encrypt notification, defaults to false
cluster	cluster	String	optional if `host` is present, it will override the `cluster` option
host	host	String	optional whether to use a different host, defaults to api.pusherapp.com
port	port	Number	optional whether to use a different port, defaults to 80 for unuseTLS and 443 for useTLS
proxy	proxy	String	optional URL to proxy the requests through
timeout	timeout	Number	optional timeout for all requests in milliseconds
keepAlive	keepAlive	Boolean	optional enables keep-alive, defaults to false
batch	batch	Object	array of events (maximum 10)

Outputs

Name	Key	Type	Description
message	message	String	a dummy 'sent' message

channels

Task key: channels

get the list of the channel within an application that have active subscriptions (also referred to as being occupied)

Inputs

Name	Key	Type	Description
appId	appId	String	optional Pusher application ID
key	key	String	optional Pusher application key
secret	secret	String	optional Pusher application secret key
useTLS	useTLS	Boolean	optional whether to encrypt notification, defaults to false
cluster	cluster	String	optional if `host` is present, it will override the `cluster` option
host	host	String	optional whether to use a different host, defaults to api.pusherapp.com
port	port	Number	optional whether to use a different port, defaults to 80 for unuseTLS and 443 for useTLS
proxy	proxy	String	optional URL to proxy the requests through
timeout	timeout	Number	optional timeout for all requests in milliseconds
keepAlive	keepAlive	Boolean	optional enables keep-alive, defaults to false
params	params	Object	optional additional parameters to be sent as query string parameters (see HTTP API Reference)

Outputs

Name	Key	Type	Description
channels	channels	String	array of channel names

channel

Task key: channel

fetch one or some attributes for a given channel

Inputs

Name	Key	Type	Description
appId	appId	String	optional Pusher application ID
key	key	String	optional Pusher application key
secret	secret	String	optional Pusher application secret key
useTLS	useTLS	Boolean	optional whether to encrypt notification, defaults to false
cluster	cluster	String	optional if `host` is present, it will override the `cluster` option
host	host	String	optional whether to use a different host, defaults to api.pusherapp.com
port	port	Number	optional whether to use a different port, defaults to 80 for unuseTLS and 443 for useTLS
proxy	proxy	String	optional URL to proxy the requests through
timeout	timeout	Number	optional timeout for all requests in milliseconds
keepAlive	keepAlive	Boolean	optional enables keep-alive, defaults to false
params	params	Object	optional additional parameters to be sent as query string parameters (see HTTP API Reference)

Outputs

Name	Key	Type	Description
occupied	occupied	Boolean	whether the channel currently has active subscriptions
user_count	user_count	Number	optional number of distinct users currently subscribed to this channel (a single user may be subscribed many times, but will only count as one)
subscription_count	subscription_count	Number	optional number of connections currently subscribed to this channel (not available by default, has to be enabled in dashboard)