Unable to connect to mongodb database with my heroku app?

Question

I am unable to connect my Node.js app deployed to Heroku with a MongoDB database. It works fine on localhost, but not on Heroku.

In my logs, I see this:

MongoNetworkError: failed to connect to server [authproject-shard-00-01-ybey8.mongodb.net:27017] on first connect [MongoNetworkError: connection 4 to authproject-shard-00-01-ybey8.mongodb.net:27017 closed]

---

custom-environment-variables.json:

{
  "db": "Auth_db"
}

default.json:

{
  "db": "mongodb://localhost/user"
}

db.js:

  const db = config.get("db");
  mongoose
    .connect(db)
    .then(() => console.log("connected to mongodb.."))
    .catch(err => console.error("could not connect to mongodb", err));
};

Answer 1

You need to configure an environment variable in your Heroku application.

Run in console:

heroku config:set MONGODB_URI='urlOfYourMongoDatabase'

Then upgrade your db.js like this:

const mongoose = require('mongoose')

mongoose.connect(process.env.MONGODB_URI || 'mongodb://localhost:27017/TodoApp', { useNewUrlParser: true })
        .then(connect => console.log('connected to mongodb..'))
        .catch(e => console.log('could not connect to mongodb', e))

module.exports = {mongoose}

Good luck!