Error R10 (Boot timeout) when running firebase node.js on Heroku - node.js

Question

I have node.js code similar to this one:
var firebase = require('firebase');
var request = require('request');
var API_KEY = "..."; // Your Firebase Cloud Server API key
firebase.initializeApp({
serviceAccount: ".json",
databaseURL: "https://.firebaseio.com/"
});
ref = firebase.database().ref();
function listenForNotificationRequests() {
var requests = ref.child('notificationRequests');
ref.on('child_added', function(requestSnapshot) {
var request = requestSnapshot.val();
sendNotificationToUser(
request.username,
request.message,
function() {
request.ref().remove();
}
);
}, function(error) {
console.error(error);
});
};
function sendNotificationToUser(username, message, onSuccess) {
request({
url: 'https://fcm.googleapis.com/fcm/send',
method: 'POST',
headers: {
'Content-Type' :' application/json',
'Authorization': 'key='+API_KEY
},
body: JSON.stringify({
notification: {
title: message
},
to : '/topics/user_'+username
})
}, function(error, response, body) {
if (error) { console.error(error); }
else if (response.statusCode >= 400) {
console.error('HTTP Error: '+response.statusCode+' - '+response.statusMessage);
}
else {
onSuccess();
}
});
}
// start listening
listenForNotificationRequests();
My question is how to run it on heroku? When I try it is giving me Error R10 (Boot timeout) -> Web process failed to bind to $PORT within 60 seconds of launch. Procfile is like this:
worker: node server.js

Answer 1

Here is my guess:
You probably have something similar to this in your code (just not posted):
var http = require('http');
http.createServer(server.js);
server.listen(5000);
Well, that server.listen(5000); is forcing the app to connect to port 5000 and listen.
Heroku doesn't work that way. It will automatically assign a port to your env and use that. So you need to tell your app "Hey, use the env port, or use 5000 as a backup". You can do this like this:
server.listen(process.env.PORT || 5000);
Again, this is just a guess considering you didn't post your code that refers to the port number. My example might differ from yours, but it's the same general concept.

Answer 2

I fixed it by this:
//add this in the begining
var express = require('express');
var app = express();
app.set('port', (process.env.PORT || 5000));
//this at the end
app.listen(app.get('port'), function() {
listenForNotificationRequests();
});