"Mongo Error : Authentication failed" can't read datas from MongoDB Atlas - node.js

Question

Today I wanted to use clusters in MongoDB Atlas to get an online DB, instead of my MongoDB local database (which worked perfectly fine),
So, I followed a mLab tutorial,
It works perfectly on writing in the database (when I auth in my website, it adds the datas in the database, when I write a message in the chat it adds the message, etc...)
But when I want to read these datas, I got :
MongoTimeoutError: Server selection timed out after 30000 ms
MongoError: Authentication failed
The connect in my server/index.js seems to work, because I got the console log :
mongoose
.connect(
`mongodb+srv://${process.env.USER}:${process.env.PASSWORD}#ofilms-demo-f9iwz.mongodb.net/test?retryWrites=true&w=majority`,
{ useNewUrlParser: true, useUnifiedTopology: true }
).then(() =>
console.log(
"working"
)
)
.catch(err => console.log(err));
but not other routes, like this one (which get all users in the database) :
const mongo = require("mongodb").MongoClient;
router.get("/getAll", function(req, res) {
console.log("get all users");
const client = new mongo(`mongodb+srv://${process.env.USER}:${process.env.PASSWORD}#ofilms-demo-f9iwz.mongodb.net/test?retryWrites=true&w=majority`, {
useNewUrlParser: true,
useUnifiedTopology: true
});
client.connect(err => {
const collection = client.db("test").collection("users");
collection.find().toArray((err, items) => {
res.json(items);
});
client.close();
});
});
One model from Mongoose :
/* eslint-disable no-undef */
const mongoose = require("mongoose");
const Schema = mongoose.Schema;
const UserSchema = new Schema({
username: {
type: String,
required: true
},
email: {
type: String,
required: true,
lowercase: true
},
password: {
type: String,
required: true
},
firstname: String,
lastname: String,
sexe: String,
mobilePhone: String,
departement: Number,
city: String,
moviesLiked: Array,
seriesLiked: Array,
moviesDisliked: Array,
seriesDisliked: Array,
moviesFavorites: Array,
seriesFavorites: Array,
lists: Array,
creationDate: {
type: Date,
default: Date.now
},
lastConnection: Date,
isVerified: Boolean,
isAdmin: Boolean,
isModerator: Boolean,
isConnected: Boolean
});
module.exports = User = mongoose.model("users", UserSchema);
I can show you the code of other files if needed, or give you the link of the repo if someone wants it, but it's a really big project,
Thanks,

Answer 1

You seem to connect mongodb with both mongoose.connect() and MongoClient.connect(), one of them will be enough.
If you want to use mongoose you can connect to mongodb in your main file (index.js or app.js), and when connected to the db your server can start listening.
And you don't need to connect mongodb in your routes.
For example:
index.js (main file)
const express = require("express");
const app = express();
require("dotenv").config();
const users = require("../routes/users"); //todo: correct the users route path
app.use("/api/users", users);
mongoose
.connect(
`mongodb+srv://${process.env.USER}:${process.env.PASSWORD}#ofilms-demo-f9iwz.mongodb.net/test?retryWrites=true&w=majority`,
{ useNewUrlParser: true, useUnifiedTopology: true }
)
.then(() => console.log("working"))
.catch(err => console.log(err));
in your route: (users.js)
const express = require("express");
const router = express.Router();
const User = require("../../models/User");
router.get("/users", async (req, res) => {
const users = await User.find({});
res.send(users);
});
module.exports = router;
As you see there is no connection related code in our route, because we have already connected when the application starts.
For this code to work, you need to add your local IP to the IP whitelist IP in mongodb atlas panel. (SECURITY --> Network Access --> IP Whitelist.
Also the user you are using to connect must have read an write priveleges.
You can check your users priveleges in SECURITY --> Database Access --> MongoDB Users.