can't connect to mongolab with node.js on heroku - node.js

I am having trouble making node.js and mongodb with mongolab work on heroku. I have read other issues like How do I setup MongoDB database on Heroku with MongoLab? and How do I manage MongoDB connections in a Node.js web application? but I still can not set up my connection. In the logs it says [Error: failed to connect to ...]
I have takend the db, host and port from the MONGOLAB_URI process env.I have the following code:
var mongoUri = mongodb://heroku_app17328644:{password}#ds037518.mongolab.com //taken from process.env.MONGOLAB_URI
var host = 'mongodb://heroku_appXXXXXX:{password}#ds037518.mongolab.com';
var port = '37518';
var database = 'heroku_appXXXXXX';
Provider.db = new Db(database, new Server(host, port, { safe: true }, { auto_reconnect: true }, {}));
Provider.db.open(function(err, db){
console.log(db); //null
if (err) console.log(err);
else console.log('success');
});
What am I doing wrong ?

The core issue seems to be that you're trying to use a MongoDB URI as a hostname.
Here's how to connect using a URI and MongoClient:
var mongodb = require('mongodb');
var uri = 'mongodb://user:pass#host:port/db';
mongodb.MongoClient.connect(uri, function (err, db) {
/* adventure! */
});
Of course you'll want to substitute the user, pass, host, port, and db in the uri for your actual connect parameters. If you're using the MongoLab add-on for Heroku you can get the URI from the environment like this:
var uri = process.env.MONGOLAB_URI;
When using MongoClient safe mode is the default, so that option can be left out. To specify auto_reconnect simply pass it as a server option.
var mongodb = require('mongodb');
var uri = 'mongodb://user:pass#host:port/db';
mongodb.MongoClient.connect(uri, { server: { auto_reconnect: true } }, function (err, db) {
/* adventure! */
});

Here's is how I do it. This way, my application connects to the "test" database on my development machine and the "mongolab" database when deployed and running on Heroku.
mongoose = require("mongoose");
mongoURI = 'mongodb://localhost/test';
mongoose.connect(process.env.MONGOLAB_URI || mongoURI);

In my own case, I queried the configuration settings heroku config and it turns out that the mongodb is added as MONGODB_URI.
So, I added process.env.MONGODB_URI to the uri such as:
var uri = process.env.MONGODB_URI || process.env.MONGOHQ_URL || process.env.MONGOLAB_URI;

Related

connect mongoDb to nodejs on localhost

I'm trying to use mongoDB for my app.
I have 2 databases and use next code to connect:
var express = require("express");
var router = express.Router();
var mongojs = require("mongojs");
//var mongo_db =
//mongojs("mongodb://xxxxx:xxxxx#some_adress/cat_mean_db", ["tasks"]);
var mongo_db = mongojs("mongodb://xxxxx:xxxxx#localhost:3000/cat_db",
["tasks"]);
//get all docs(pages)
router.get("/tasks", function (req, res, next ) {
mongo_db.tasks.find(function (error, tasks) {
if(error)
res.send(error);
res.json(tasks);
});
});
if I use this db
var mongo_db =
mongojs("mongodb://xxxxx:xxxxx#some_adress/cat_mean_db",
["tasks"]);
everything is working well, but when I try to use db on localhost I got an exeption: connection 0 to localhost:3000 closed
the local db is exist and has user for shure.
From mongoose documentation on NPM :
Note: If the local connection fails then try using 127.0.0.1 instead of localhost. Sometimes issues may arise when the local hostname has been changed.
You should try using 127.0.0.1 instead of localhost.

Mongoose never returns its promise when I try to connect to the same db using a working URL

I have a locally hosted mongodb that I can connect to using mongodb.MongoClient.
Working code:
var mongoClient = require("mongodb").MongoClient;
...
var startApp = function(db) {
// Get our collections in an easy to use format
var database = {
chats: db.collection('chats'),
messages: db.collection('messages')
};
// Configure our routes
require('./app/routes')(app, database);
// START APP
// Start app on port
app.listen(port);
// Tell user the app is running
console.log("App running on port " + port);
// Expose app
exports = module.exports = app;
}
// DATABASE
var database = null;
mongoClient.connect(config.url, function(err, returnDB) {
if(err) {
console.log(err);
} else {
console.log("DB connected");
startApp(returnDB);
}
});
Legacy code that no longer works:
var mongoose = require('mongoose');
...
// Connect to DB
console.log('Connect to database (' + db.url + ')');
mongoose.connect(db.url);
I have added a callback to this connect method but it never gets called (error or no error, this connect function never gets to my callback).
This entire legacy app relies on the API using mongoose to talk to the database so I do not want to redo it all using mongodb. How can I fix this?
*config.url and db.url are loaded from the same file and it is a valid and running mongodb.
It was really easy to fix. Thanks #Bhavik for asking me what version I was using.
I updated mongoose to 4.8.1 by specifying the newest version in packages.json and the issue is resolved.

How to connect MongoDB intermediate server in node js

Local server: 11.18.3.1
Intermediate server: 11.18.3.2
MongoDB Server: 11.18.3.3
Node application is running in 11.18.3.1 server.
We can't connect directly to 11.18.3.3 (MongoDB server) from 11.18.3.1. So first I need to connect 11.18.3.2 then 11.18.3.3. the below code is not working. How can we do this? we need to pass first server stream into the second server.
var client = require('ssh2').Client;
server_ssh = new client();
server_ssh.on('ready', function() {
ts_socket.emit('log', "Server connected");
// from here I want to connect to MongoDB
var MongoClient = require('mongodb').MongoClient
, Server = require('mongodb').Server;
var mongoClient = new MongoClient(new Server('11.18.3.3', 27017));
mongoClient.open(function(err, mongoClient) {
var db1 = mongoClient.db("mydb");
mongoClient.close();
});
}).connect(
{ "host": "11.18.3.2",
"username":"myuser",
"password":"mypassword",
"port":22
}
);
please help.

node.js mongo db write concern

I am running node.js 10.22, windows 8 and mongodb not sure what version, but I just downloaded it today, when I run my code I am getting a message, please ensure you set the default write concern, I am trying to follow a YouTube video, and there is mention of this, and I am finding little about it on the internet, from what i found, when I set the db i should set j:true, or safe : true/false, but neither not working for me. I do get the console log that I'm connected and the host and port, but then I get the write concern message and can't type or do anything.
var mongo = require('mongodb');
var host = "127.0.0.1";
var port = mongo.Connection.DEFAULT_PORT;
var db = new mongo.Db("nodeintro", new mongo.Server(host,port,{Fsync: true}));
db.open(function(error){
console.log("we are connected"+host + port);
})
Tried this all type of ways as well, still no luck, best i did was get back to the db write concern message, but was not able to even connect this time. What I'm really looking for is to be able to insert anything in mongo db, and i can figure out the rest.
var Db = require('mongodb').Db;
var Connection = require('mongodb').Connection;
var Server = require('mongodb').Server;
var BSON = require('mongodb').BSON;
var ObjectID = require('mongodb').ObjectID;
var host = "127.0.0.1";
var port = mongo.DEFAULT_PORT;
ArticleProvider = function(host, port) {
this.db= new Db('node-mongo-blog', new Server(host, port, {auto_reconnect: true}, {}));
this.db.open(function(error){
if(error){
console.log(error)
}
else{
console.log(port,host)
}
});
};
ArticleProvider(host,port)
When using mongodb-native directly, you should now use MongoClient.connect to open a database connection pool. It will set a default write concern for you.
var mongodb = require('mongodb');
mongodb.MongoClient.connect('mongodb://localhost/nodeintro', function(err, db) {
// db is your open nodeintro database connection pool here
});
MongoClient was a somewhat recent addition so the tutorial you're working from likely pre-dates it.
If you use {w:1} parameter in your insert or update operation, you might give this error. To overcome you can use {journal:true} parameter in your db settings.
For instance;
var Db = require('mongodb').Db,
MongoClient = require('mongodb').MongoClient,
Server = require('mongodb').Server,
ReplSetServers = require('mongodb').ReplSetServers,
ObjectID = require('mongodb').ObjectID,
Binary = require('mongodb').Binary,
GridStore = require('mongodb').GridStore,
Grid = require('mongodb').Grid,
Code = require('mongodb').Code,
BSON = require('mongodb').pure().BSON;
var db = new Db('Your DB Name', new Server('192.168.170.128', 27017), { journal : true });
db.open(function(err, db) {
var collection = db.collection('user');
collection.findOne({'_id':req.session.User._id}, function(err, user){
// some codes what do you want
collection.save( user, {w: 1}, function(err, user_id) {
// just close the db connection
db.close();
});
});
});

Setting up mongodb on Heroku with Node

On my local host, I have the following Node code to setup a mongoDB database name "dbname":
users.js:
var MongoClient = require("mongodb").MongoClient,
Connection = require("mongodb").Connection,
Server = require("mongodb").Server;
Users = function(host, port) {
var mongoClient = new MongoClient(new Server(host, port));
mongoClient.open(function (){});
this.db = mongoClient.db("dbname");
};
Users.prototype.getCollection = function (callback) {
this.db.collection("users", function (error, users) {
if (error) callback(error);
else callback(null, users);
});
};
Users.prototype.findAll = function (callback) {
this.getCollection(function (error, users) {
if (error) {
callback(error);
} else {
users.find().toArray(function (error, results) {
if (error) {
callback(error);
} else {
callback(null,results);
}
});
}
});
}
// Bunch of other prototype functions...
exports.Users = Users;
I like to put the above database functionality in one file, and then in my main server file require that file as follows:
server.js:
var Users = require("./users").Users;
var users = new Users("localhost", 27017);
users.findAll(function (err, user) {
// Do something
});
To have this working on localhost is pretty easy. In the command line, I just type the following:
$ mongod # to launch the database server
$ node server.js # to launch the web server
and it works fine. However, now I'm trying to push the whole thing onto Heroku with the mongolab addon
heroku addons:add mongolab
but the database is not running and I have no idea how to make it run. This tutorial explains how to setup mongodb with the mongolab URI, but that's not how my code works, I use a host and a port and I create a new server based on that. How should I change my code for it to work on the heroku app? I want to keep the database code in a separate file, with the prototype functions.
Follow the example here at the "MongoClient.connect" section.
Essentially, you will need to change this part of the code:
Users = function(host, port) {
var mongoClient = new MongoClient(new Server(host, port));
mongoClient.open(function (){});
this.db = mongoClient.db("dbname");
};
To use mongoClient.connect() instead of new MongoClient:
Users = function(url) {
MongoClient.connect(url, function(err, db) {
// Find better way to set this since this callback is asynchronous.
this.db = db;
});
};
If you are using node, I recommend using a library such as mongoose npm install mongoose to handle mongodb interactions. Look at my answer here for how to structure your schemas.
Helped by Xinzz's answer, here's the modified code, so that the mongodb database is initialized with a URI instead of host + port. That's how Heroku initializes the mongodb database, and that's why it wasn't working.
var mongodb = require("mongodb");
var MONGODB_URI = process.env.MONGOLAB_URI || process.env.MONGOHQ_URL || "mongodb://localhost", // Make sure to replace that URI with the one provided by MongoLab
db,
users;
mongodb.MongoClient.connect(MONGODB_URI, function (err, database) {
if (err) throw err;
db = database;
users = db.collection("users");
accounts = db.collection("accounts");
var server = app.listen(process.env.PORT || 3000);
console.log("Express server started on port %s", server.address().port);
});
The key here is to declare the variables db and users upfront, assign them a value in the asynchronous callback of the connect function of MongoClient and also start the app (app.listen(...)) in the same callback. Then later in the code I can do the following:
users.find().toArray(function (err, results) {
// Do something
});
I also gave up on all these prototype functions, since they did not really add much.

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