Embedded node-red in a feathersjs application get websocket error - websocket

Question

I can embed node-red with a custom service with the following node-red.service.js :
// Initializes the `node-red` service on path `/red`
const { NodeRed } = require('./node-red.class');
const hooks = require('./node-red.hooks');
const RED = require("node-red");
module.exports = function (app) {
const paginate = app.get('paginate');
const options = {
paginate
};
// Create the node-red settings object
const settings = {
httpAdminRoot:"/red",
httpNodeRoot: "/red",
userDir: "./red",
functionGlobalContext: { } // enables global context
};
// Initialise the runtime with a server and settings
RED.init(app,settings);
// Serve the editor UI from /red
app.use('/red' , RED.httpAdmin );
RED.start()
};
If I go to localhost:3030/red I get the node-red page, but after few seconds it lost connection to server with the following error:
WebSocket connection to 'ws://localhost:3030/red/comms' failed: Error in connection establishment: net::ERR_CONNECTION_REFUSED
I think there is a problem serving thru websocket or maybe since /red/comms is not defined in feathersjs it can't connect. Any idea?
Thank you

Answer 1

The issue comes with this line:
// Initialise the runtime with a server and settings
RED.init(app,settings);
As the comment says, you need to initialise the runtime with a server object. Here you are passing it an Express application, not a server.
It is not possible to mount websocket listeners on an express app - Node-RED needs access to the underlying HTTP Server object.
I am not familiar with what apis featherjs provides, but it does appear to allow you access to the http server object - for example by calling app.listen yourself - https://docs.feathersjs.com/api/express.html#app-listen-port