如何将heroku服务器连接到mongodb？

Question

Beginner with node.js I have an issue to deploy server on heroku.

I made a server.js application which use mongodb. It's work fine when I run the server on local ( http://localhost:3000 ) with "npm start" cmd, I'm able to connect to my mongo database by the command :

mongoose.connect(
'mongodb+srv://yolanpibrac:mypassword@cluster0-7z1th.mongodb.net/test?                        retryWrites=true&w=majority';, 
{ useNewUrlParser: true })  

(I followed this tutorial : [ https://appdividend.com/2018/04/14/how-to-deploy-nodejs-app-to-heroku/] )

But when i deploy my app on heroku, the app can not connect to mongo db. I have the following error (by checking : heroku logs -t) :

2019-08-06T21:06:33.086146+00:00 heroku[web.1]: Starting process with     command `node src/server.js`
2019-08-06T21:06:35.404641+00:00 heroku[web.1]: State changed from     starting to up
2019-08-06T21:06:35.058357+00:00 app[web.1]: Listening on port 26845
2019-08-06T21:06:36.144056+00:00 app[web.1]: Error while DB connecting
2019-08-06T21:06:36.149809+00:00 app[web.1]: { MongoNetworkError: failed     to connect to server [cluster0-shard-00-00-7z1th.mongodb.net:27017] on first     connect [MongoNetworkError: connection 5 to cluster0-shard-00-00-    7z1th.mongodb.net:27017 closed]
2019-08-06T21:06:36.149812+00:00 app[web.1]: at Pool.<anonymous>     (/app/node_modules/mongodb-core/lib/topologies/server.js:431:11)
2019-08-06T21:06:36.149814+00:00 app[web.1]: at Pool.emit     (events.js:189:13)
2019-08-06T21:06:36.149815+00:00 app[web.1]: at connect     (/app/node_modules/mongodb-core/lib/connection/pool.js:557:14)
2019-08-06T21:06:36.149816+00:00 app[web.1]: at callback     (/app/node_modules/mongodb-core/lib/connection/connect.js:109:5)
2019-08-06T21:06:36.149818+00:00 app[web.1]: at runCommand     (/app/node_modules/mongodb-core/lib/connection/connect.js:129:7)
2019-08-06T21:06:36.149819+00:00 app[web.1]: at Connection.errorHandler     (/app/node_modules/mongodb-core/lib/connection/connect.js:321:5)
2019-08-06T21:06:36.149820+00:00 app[web.1]: at Object.onceWrapper     (events.js:277:13)
2019-08-06T21:06:36.149821+00:00 app[web.1]: at Connection.emit     (events.js:189:13)
2019-08-06T21:06:36.149823+00:00 app[web.1]: at TLSSocket.<anonymous>     (/app/node_modules/mongodb-core/lib/connection/connection.js:350:12)
2019-08-06T21:06:36.149824+00:00 app[web.1]: at Object.onceWrapper     (events.js:277:13)
2019-08-06T21:06:36.149825+00:00 app[web.1]: at TLSSocket.emit     (events.js:189:13)
2019-08-06T21:06:36.149826+00:00 app[web.1]: at _handle.close     (net.js:613:12)
2019-08-06T21:06:36.149828+00:00 app[web.1]: at TCP.done     (_tls_wrap.js:386:7)
2019-08-06T21:06:36.149829+00:00 app[web.1]: name: 'MongoNetworkError',
2019-08-06T21:06:36.149830+00:00 app[web.1]: errorLabels: [     'TransientTransactionError' ],
2019-08-06T21:06:36.149832+00:00 app[web.1]:     [Symbol(mongoErrorContextSymbol)]: {} }

I already read all issues related to this problem, but none of the solution worked. I have mongodb account with cluster connexion string I was carefull in my password that any special characters are URL encoded. I have a procfile : web: node src/server.js and an index.html file

my server.js file :

//Définition des modules
const express = require("express");
const mongoose = require("mongoose");
const bodyParser = require('body-parser');
const app = express();
const path = require('path');



const dbRoute = 'mongodb+srv://yolanpibrac:mypassword@cluster0-    7z1th.mongodb.net/test?retryWrites=true&w=majority';
const dbRouteLocal = 'mongodb://localhost/db';
//Connexion à la base de donnée
mongoose.connect(dbRoute, { useNewUrlParser: true }).then(() => {
    console.log('Connected to mongoDB')
}).catch(e => {
    console.log('Error while DB connecting');
    console.log(e);
});



var urlencodedParser = bodyParser.urlencoded({
    extended: true
});
app.use(urlencodedParser);
app.use(bodyParser.json({limit: '10mb', extended: true}));

//Définition des CORS
app.use(function (req, res, next) {
    res.setHeader('Access-Control-Allow-Headers', 'Origin,X-Requested-    With,content-type,Accept,content-type,application/json');
    res.setHeader('Access-Control-Allow-Origin', '*');
    res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS,     PUT, PATCH, DELETE');
    res.setHeader('Access-Control-Allow-Credentials', true);
    next();
});



var router = express.Router();
app.use('/user', router);
require(__dirname + '/controllers/userController')(router);


app.get('/', function(req, res) {
    res.sendFile(path.join(__dirname, 'index.html'));
});
app.get('*', function(req, res) {
    res.sendFile(path.join(__dirname, 'index.html'));
});

//Définition et mise en place du port d'écoute
var port = process.env.PORT || "3000";

app.listen(port, () => console.log(`Listening on port ${port}`));

my package.json :

{
  "name": "movies-displayer",
  "version": "0.1.0",
  "engines": {
    "node": "11.4.0"
  },
  "private": true,
  "proxy": "http://yolan-pibrac.com",
  "dependencies": {
    "animated": "^0.2.2",
    "axios": "^0.19.0",
    "body-parser": "^1.19.0",
    "bootstrap": "^4.3.1",
    "express": "^4.17.1",
    "jwt-simple": "^0.5.6",
    "mongodb": "^3.3.0-beta2",
    "mongoose": "^5.6.8",
    "password-hash": "^1.2.2",
    "react": "^16.8.6",
    "react-activity": "^1.2.2",
    "react-animations": "^1.0.0",
    "react-bootstrap": "^0.32.1",
    "react-bootstrap-dropdown-menu": "^1.1.15",
    "react-dom": "^16.8.6",
    "react-multi-carousel": "^2.1.2",
    "react-popper": "^1.3.3",
    "react-pose": "^4.0.8",
    "react-redux": "^7.0.3",
    "react-router": "^4.3.1",
    "react-router-dom": "^4.3.1",
    "react-scripts": "3.0.1",
    "react-state-animation": "^0.1.0",
    "reactstrap": "^8.0.1",
    "redux": "^4.0.1",
    "styled-components": "^4.3.2"
  },
  "scripts": {
    "start": "node src/server.js"
  },
  "eslintConfig": {
    "extends": "react-app"
  },
  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  }
}

I can provide more details if needed ! Thank you for your help,

Answer 1

You may need to allow heroku to access your mongodb server.

You can do this by logging in to Mongodb atlas and clicking on Network access on the left side under security settings, then click add ip address on the right top and enter 0.0.0.0/0 as the ip address to allow access from all ip's a or add your heroku servers' specific ip if you can get it.