Get data from socket connection without sending it again - websocket

Question

For a API request I send the jwt with authentication header while request. So I get informations from the jwt. But with websocket it is not possible to set headers.
I also do not want to set the jwt as data in every request. So I want to implement a authentication (server side), witch save data from the jwt to a redis DB with the socket id as an key.
Now I have the problem, that the socket or socket id is not part of the feathers context in hooks or only available as symbol witch I do not figure out how to get it right now. But I think there have to be a more elegant version of how to save data in combination with sockets and get theme back again.
Which is the best way to save user data in a socket connection, to not send the data everytime again?
Mabye it will also help if somebody can tell me how to read the Symbol in the following structur:
connection: {provider: "socketio", Symbol(#feathersjs/socketio/socket): Socket}

Answer 1

How to authenticate a socket connection without the Feathers client is described in the API documentation here. This can be done by authenticating the connection like this:
const io = require('socket.io-client');
const socket = io('http://localhost:3030');
socket.emit('create', 'authentication', {
strategy: 'local',
email: 'hello#feathersjs.com',
password: 'supersecret'
}, function(error, authResult) {
console.log(authResult);
// authResult will be {"accessToken": "your token", "user": user }
// You can now send authenticated messages to the server
});
Or by sending the existing access token when establishing the socket connection:
const io = require('socket.io-client');
const socket = io('http://localhost:3030', {
extraHeaders: {
Authorization: `Bearer <accessToken here>`
}
});

Answer 2

I found a soltuion in a simular question: How to add parameters to a FeathersJS socket connection
It is possible to save information to the connection by adding it to socket.feathers and it will added as params in every following request.
Socketio Middleware
const jwtHandler = (feathers, authorization, next) => {
    const regex = /Bearer (.+)/g;
    const jwt = (regex.exec(authorization) || [])[1]; // todo length >= 2 test.
    try {
        const { accountId, userId } = decode(jwt);
        feathers.accountId = accountId;
        feathers.userId = userId;
        feathers.authorization = authorization;
    } catch (err) {
        throw new Forbidden('No valid JWT', err);
    }
    next();
};
const socketJwtHandler = io => io.use((socket, next) => {
    jwtHandler(socket.feathers, socket.handshake.query.authorization, next);
});
and than calling context.param.userId in hooks.