Keker

Easy to use pub-sub message broker via websocket.

About:

In recent time become very popular - SPA(single page applications), when all 'view' it`s - 'javascript bundle', which loads on client side and communicates with 'backend' API.

Sometimes SPA wants to provide some interactive events for it's clients, like - friendship request, new message request or something else. So, there are many ways to provide it, Let's look at most popular:

• polling (Bad way, because this generates unnecessary load on the server(API) without the guarantee of getting the desired(new) data)
• websocket (Right way, SPA makes only one TCP (full-duplex) connection and waits from backend for new data)

Keker provides websocket's for SPA, for subscriptions, and event listener URL, where the backend sends all events.

How to use:

Build keker

git clone https://github.com/tears-of-noobs/keker.git
cd keker
make

Run keker

./out/kekerd

After start kekerd listen on all interfaces, port - 3498. You may change some default values, see --help for additional information.

Connecting SPA to kekerd

WARNING: You must send HELLO message when your connection is open. Format is simple - HELLO <AUTH_INFO>, where <AUTH_INFO> it's information about client (name, auth token, etc...). If you don't send HELLO message, connection will be fail after one minute.

var socket = new WebSocket("ws://YOU_KEKER_IP:3498/v1/subscribe");

socket.onopen = () => {
    socket.send(`HELLO ${authToken}`);
};

socket.onmessage = function(event) {
  console.log(event.data);
};

Publish events from backend

For publishing events you can send HTTP request with data in arbitrary format(JSON, plain text, etc...) to URL - http://YOU_KEKER_IP:3498/v1/publish, with Header - Token: <AUTH_INFO>, where <AUTH_INFO> - client identificator which used by SPA for subscribing to events.

Thats all :)

License

MIT