MongoError: not authorized for query - node.js

Question

I have a small Node.js/ Express/ Mongoose app which I have running on an AWS - EC2 instance built using Bitnami AMI, whenever I try to run .find on my app MongoDB collection using Chrome Postman I get the following result.
{
"name": "MongoError"
}
[MongoError: not authorized for query on projectDB.areas]
I tried using the following 3 connection strings but all 3 returned the same result, can someone please help by telling me what I am missing / doing wrong here? Thanks
var connectionString = 'mongodb://localhost:27017/'+dbName;
var connectionString = 'mongodb://root:bitnami#localhost:27017/'+dbName;
var connectionString = 'mongodb://root#localhost:27017/'+dbName;
My node.js app code:
area.js
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var areaSchema = new Schema({
name: { type: String, required: true },
});
module.exports = mongoose.model('Area', areaSchema);
areas.js
var Area = require('../app/models/area');
var express = require('express');
var router = express.Router();
router.route('/').get(function(req, res){
Area.find(function(err, areas){
if(err){
return res.send(err);
}
res.json(areas);
//res.send({sucess:true, areas:areas})
});
});
app.js
var express = require('express');
var bodyParser = require('body-parser');
var mongoose = require('mongoose');
var areas = require('./routes/areas');
var app = express();
app.set('port', process.env.PORT || 8080);
app.use(bodyParser.json({ type: 'application/*+json' }));
var dbName = 'projectDB';
var connectionString = 'mongodb://localhost:27017/'+dbName;
// var connectionString = 'mongodb://root:bitnami#localhost:27017/'+dbName;
// var connectionString = 'mongodb://root#localhost:27017/'+dbName;
////////Tried the above 3 connection strings, none worked...
mongoose.connect(connectionString, function(err){
if(err){
throw err;
}
});
var corsOptions = {
origin: '*',
allowedHeaders: ['Content-Type'],
methods: ['POST','GET','PUT','DELETE'],
credentials: true
};
app.use(cors(corsOptions));
app.use('/api/areas', areas);
module.exports = app;
www.js
var app = require('../app');
var server = app.listen(app.get('port'), function(){
console.log('Server running on port: '+ server.address().port);
});

Answer 1

Since, running $ mongo admin --username root --password bitnami didn't take you into a Mongo shell.
Assuming that you ran that code on the server and not your local machine, this only means your MongoDB has not been properly setup. You should probably remove the instance completely from AWS and start setting up from scratch. Otherwise, simply follow the instructions on MongoDB website to install MongoDB.
Also, for Node.js use the following code to ensure that you have actually connected:
`
mongoose.connect("mongodb://root#localhost:27017/projectDB");
var db = mongoose.connection;
db.once('open', function () {
console.log('MongoDB connection successful.');
});
`