socket-redis

socket-redis is a WebSocket pub/sub server and client, exposing an API over Redis (allowing you to use WebSocket functionality in your application using a Redis client).

About

socket-redis starts a WebSocket emulation server (SockJS) where clients can connect to, and subscribe to multiple channels. The server will let you consume client-related events like message, subscribe and unsubscribe on a Redis pub/sub channel socket-redis-up. Additionally it will subscribe to another pub/sub channel socket-redis-down where you can send messages to all clients in a channel.

When specifying multiple --socket-ports the script will spawn a child process for each port. This is provided as a simple way to make use of all your CPU cores.

Publishing

• update package.json with a new version
• release a new git tag with the updated package.json

After that the npm release should be done automatically. If it didn't happen then release it manually:

npm publish https://github.com/cargomedia/socket-redis/archive/<GitTagWithUpdatedPackageJson>.tar.gz

Server

Installation

Package is in nodejs and is available through npm registry:

npm install socket-redis [-g]

Running

You can run socket-redis using default arguments or specify them on your own.

Example:

socket-redis --socket-ports=8090,8091,8092

Available options:

• --redis-host Specify host of redis server. Defaults to localhost.
• --socket-ports Comma separated public ports which SockJS workers will listen on. Defaults to 8090.
• --log-dir Directory where log is stored. Script will try to create directory if needed. Defaults to null which means it will output to stdout.
• --sockjs-client-url Specify custom url for sockjs-client library.
• --status-port Specify port for http status requests. It should not be publicly accesible. Defaults to 8085
• --status-secret Specify secret token to allow/deny http status requests.
• --ssl-key Specify ssl private key file. Combine with ssl-cert option.
• --ssl-cert Specify ssl public certificate file. Combine with ssl-key option. Append CA-chain within this file.
• --ssl-pfx Specify ssl pfx file (key + cert). Overrides ssl-key and ssl-cert options.
• --ssl-passphrase Specify file containing the ssl passphrase.

with Docker

docker-compose up socket-redis

In development, you can mount the repository has a volume and expose ports manually

docker-compose run --volume $(pwd):/opt/socket-redis -p 8085:8085 -p 8090:8090 -p 8091:8091 socket-redis

Test

docker-compose run -e REDIS_HOST=redis socket-redis ./script/test.sh

In development, you can mount the repository as a volume, then node modules will be installed on you host an reused for each run

docker-compose run --volume $(pwd):/opt/socket-redis -e REDIS_HOST=redis socket-redis ./script/test.sh

Messages published to redis pub/sub channel socket-redis-up:

• {type: "subscribe", data: {channel: <channel>, clientKey: <clientKey>, data: <subscribe-data>}}
• {type: "unsubscribe", data: {channel: <channel>, clientKey: <clientKey>}}
• {type: "message", data: {clientKey: <clientKey>, data: <data>}}

Messages which are detected on redis pub/sub channel socket-redis-down:

• {type: "publish", data: {channel: <channel>, event: <event>, data: <data>}}

For example you could publish messages using Redis CLI:

redis-cli 'publish' 'socket-redis-down' '{"type":"publish", "data": {"channel":"<channel>", "event":"<event>", "data":"<data>"}}'

Status request

Server also answers http requests (on port 8085 by default). You can request on-demand state of all subscribers grouped by channels.

Status response schema:

{<channel>: {
	"subscribers": {
		<clientKey>: {
			"clientKey": <clientKey>,
			"subscribeStamp": <subscribe-stamp>,
			"data": {}
		}
	}
}

Client

Building

Client is written as a node module. If you want to access it as a global variable in browser then you need to browserify client/index.js. It will be exposed under SocketRedis. Also it requires a global variable SockJS that contains sockjs client.

browserify --standalone SocketRedis ./client/index.js -o ./client/socket-redis.js

Installation

Include the SockJS and socket-redis client libraries in your html file:

<script src="http://cdn.sockjs.org/sockjs-0.3.min.js"></script>
<script src="https://raw.github.com/cargomedia/socket-redis/master/client/socket-redis.js"></script>

Example

To receive messages from the server create a new SocketRedis instance and subscribe to some channels:

var socketRedis = new SocketRedis('http://example.com:8090');
socketRedis.onopen = function() {
	socketRedis.subscribe('channel-name', null, {foo: 'bar'}, function(event, data) {
		console.log('New event `' + event + '` on channel `channel-name`:', data);
	});

	socketRedis.unsubscribe('channel-name');
};
socketRedis.open();

To publish messages to a channel from the client:

socketRedis.publish('channel-name', 'event-name', {foo: 'bar'});

(The event name will be prefixed with client- and thus become client-event-name.)

To send messages to the server:

socketRedis.send({foo: 'bar'});