mesg-pusher

MESG Service for Pusher ID: com.mesg.pusher

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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

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 |

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 |

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 |

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) |