AWS WebSocket Wrapper to provide socket.io like interface to NodeJS serverless handlers
npm install aws-websocket-server
Add Socket.io like wrapper to AWS WebSocket server(NodeJS serverless)
This package uses MongoDB as database to record connection & channel subscription.
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npm install aws-websocket-server
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- Vaild MongoDB Url
- API WEBSOCKET Endpoint from AWS
- AWS Websocket client wrapper to communicate with client using server wrapper.
npm install aws-websocket-client
Github:- https://github.com/racop/aws-websocket-client
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import AWSWebSocketServer from "aws-websocket-server";
const DB_URI = "mongodb+srv://username:password@connection_url"; // You mongodb connection url
const socket = new AWSWebSocketServer({
mongoDBURI: DB_URI,
socketConnectionModel = SocketConnection, // Optional, By default uses ./models/socketConnection.model.js
socketChannelModel = SocketChannel, // Optional, By default uses ./models/socketChannel.model.js
debug: false,
})
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On connectHandler
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module.exports.connectHandler = (event, context, callback) => {
context.callbackWaitsForEmptyEventLoop = false;
socket.addConnection(event.requestContext.connectionId) // Register connection in socket
.then(() => {
// do something like subscribe to channels
socket.subscribe('global', event.requestContext.connectionId); // Subscribed to channel name global
callback(null, successfullResponse)
})
.catch((err) => {
callback({statusCode: 500,body: JSON.stringify(err)})
})
}
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On disconnectHandler
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module.exports.disconnectHandler = (event, context, callback) => {
context.callbackWaitsForEmptyEventLoop = false;
socket.deleteConnection(event.requestContext.connectionId) // DeRegister connection in socket
.then(() => {
callback(null, successfullResponse)
})
.catch((err) => {
console.log(err)
callback(failedResponse(500, JSON.stringify(err)))
})
}
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On subscribeHandler
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module.exports.subscribeHandler = (event, context, callback) => {
context.callbackWaitsForEmptyEventLoop = false;
const channelName = JSON.parse(event.body).data;
socket.subscribe(channelName, event.requestContext.connectionId) // Subscribe the channel
.then(() => {
callback(null, successfullResponse)
})
.catch((err) => {
console.log(err)
callback(failedResponse(500, JSON.stringify(err)))
})
}
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On unsubscribeHandler
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module.exports.unsubscribeHandler = (event, context, callback) => {
context.callbackWaitsForEmptyEventLoop = false;
const channelName = JSON.parse(event.body).data;
socket.subscribe(channelName, event.requestContext.connectionId) // Unsubscribe the channel
.then(() => {
callback(null, successfullResponse)
})
.catch((err) => {
console.log(err)
callback(failedResponse(500, JSON.stringify(err)))
})
}
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On sendMessageHandler
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module.exports.sendMessageHandler = async (event, context) => {
context.callbackWaitsForEmptyEventLoop = false;
const connectionId = event.requestContext.connectionId; // Client connectionId
const data = JSON.parse(event.body).data;
const eventListener = data.event; // EventListener received from client
const messageBody = data.body; // Received Data from client
// Do something based on the eventListener and data received from client
await socket.in("global").emit(event, 'online', messageBody); // Send message to all clients subscribed to global channel on online listener.
return { statusCode: 200, body: 'Data sent.' };
};
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socket.broadcast().emit(event, listener, message); // Send message to all connected clients with on provided listener
Eg:-
// This can be used to inform all clients listening to online listener about Bob
await socket.broadcast().emit(event, 'online', {name:"Bob"});
await socket.to("global").emit(event, 'friend_request', message); // Send message to all clients subscribed to global channel except sender
Eg:-
// Send message to all clients subscribed to global channel on frined_request listener except sender.
await socket.to("global").emit(event, 'friend_request', {id:1, name: "John"});
await socket.to("global").emit(event, 'friend_request', message); // Send message to all clients subscribed to global channel including sender
Eg:-
// Send message to all clients subscribed to global channel on frined_request listener including sender.
await socket.to("global").emit(event, 'friend_request', {id:1, name: "John"});
``