Unable to access web server on Heroku

Question

I am following this tutorial/guide . Locally, it works, using localhost as the domain, and 8080 as the port.

Here's the local configuration:

"dashboard" : {
    "oauthSecret": `${process.env.oauthSecret}`,
    "callbackURL": `http://localhost:8080/callback`,
    "sessionSecret": "fakesessionsecret",
    "domain": "localhost",
    "port": 8080
  },

But now, I would like to use the app on Heroku, and access the web dashboard through https://project-name.herokuapp.com or through a custom domain, which I linked already to the DNS provided, in format dashboard.example.com .

localhost and/or the port does not work for Heroku, so I'm not sure what to change it to for it to work. I have already tried to change the domain to xxx.herokudns.com , port to process.env.PORT , domain to the custom one I set in Heroku - but they all result in the app crashing with status 503 when I visit the URL.

From what I see, the configuration domains and ports are used in these codes:

const express = require("express");
const app = express();
const passport = require("passport");

passport.use(new Strategy({
    clientID: client.appInfo.id,
    clientSecret: config.dashboard.oauthSecret, //from configuration
    callbackURL: config.dashboard.callbackURL, //from configuration
    scope: ["identify", "guilds"]
  }
...
app.locals.domain = config.dashboard.domain;
...
app.listen(client.config.dashboard.port);

So how do I access the web application from Heroku?

Answer 1

When you get a 503, are you checking your Heroku logs? They should provide specific info about what's causing the crash.

The domain should be dashboard.example.com and the port should be process.env.PORT . Better still, use dotenv and a .env file to define your environment variables locally, and use Heroku's "Settings" tab to set the environment variables in production (in this instance, just domain – port is already set for you on each app launch).