从MongoDB中去MongoLab如何使用Node.js

Question

我试图做同样的事情这家伙的在这里做How do I setup MongoDB database on Heroku with MongoLab?

应用程序是否运行在Amazon EC2上，我部署到Heroku的与MongoLabs附加。

我应该输入什么来改变mongo连接到Mongo URI？

Heroku的文档

/** https://devcenter.heroku.com/articles/getting-started-with-nodejs#write-your-app */ 

var mongo = require('mongodb'); 

var mongoUri = process.env.MONGOLAB_URI || 
    process.env.MONGOHQ_URL || 
    'mongodb://localhost/mydb'; 

mongo.Db.connect(mongoUri, function (err, db) { 
    db.collection('mydocs', function(er, collection) { 
    collection.insert({'mykey': 'myvalue'}, {safe: true}, function(er,rs) { 
    }); 
    }); 
}); 

---

app.js

/** app.js */ 

var express = require('express') 
    , routes = require('./routes') 
    , user = require('./routes/user') 
    , http = require('http') 
    , path = require('path') 
    , EmployeeProvider = require('./employeeprovider').EmployeeProvider; 

var app = express(); 

app.configure(function(){ 
    app.set('port', process.env.PORT || 8080); 
    app.set('views', __dirname + '/views'); 
    app.set('view engine', 'jade'); 
    app.set('view options', {layout: false}); 
    app.use(express.favicon()); 
    app.use(express.logger('dev')); 
    app.use(express.bodyParser()); 
    app.use(express.methodOverride()); 
    app.use(app.router); 
    app.use(require('stylus').middleware(__dirname + '/public')); 
    app.use(express.static(path.join(__dirname, 'public'))); 
}); 

app.configure('development', function(){ 
    app.use(express.errorHandler()); 
}); 

var employeeProvider= new EmployeeProvider('localhost', 27017); 

//Routes 

app.get('/', function(req, res){ 
    employeeProvider.findAll(function(error, emps){ 
     res.render('index', { 
      title: 'Employees', 
      employees:emps 
     }); 
    }); 
}); 

app.get('/employee/new', function(req, res) { 
    res.render('employee_new', { 
     title: 'New Employee' 
    }); 
}); 

//save new employee 
app.post('/employee/new', function(req, res){ 
    employeeProvider.save({ 
    title: req.param('title'), 
     name: req.param('name') 
    }, function(error, docs) { 
     res.redirect('/') 
    }); 
}); 

app.listen(8080); 

employeeprovider.js

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; 

EmployeeProvider = function(host, port) { 
    this.db= new Db('node-mongo-employee', new Server(host, port, {safe: true},   {auto_reconnect: true}, {})); 
    this.db.open(function(){}); 
}; 


EmployeeProvider.prototype.getCollection= function(callback) { 
    this.db.collection('employees', function(error, employee_collection) { 
    if(error) callback(error); 
    else callback(null, employee_collection); 
    }); 
}; 

//find all employees 
EmployeeProvider.prototype.findAll = function(callback) { 
    this.getCollection(function(error, employee_collection) { 
     if(error) callback(error) 
     else { 
     employee_collection.find().toArray(function(error, results) { 
      if(error) callback(error) 
      else callback(null, results) 
     }); 
     } 
    }); 
}; 

//save new employee 
EmployeeProvider.prototype.save = function(employees, callback) { 
    this.getCollection(function(error, employee_collection) { 
     if(error) callback(error) 
     else { 
     if(typeof(employees.length)=="undefined") 
      employees = [employees]; 

     for(var i =0;i< employees.length;i++) { 
      employee = employees[i]; 
      employee.created_at = new Date(); 
     } 

     employee_collection.insert(employees, function() { 
      callback(null, employees); 
     }); 
     } 
    }); 
}; 

exports.EmployeeProvider = EmployeeProvider; 

我将如何改变employeeProvider使用URI，而不是本地主机？

Answer 1

我用MongoHQ但其类似的，首先你需要为你的数据库中创建用户插件，然后添加凭据URI（你应该看到URI在蒙戈插件） 例如：

的MongoDB： //user:pass@paulo.mongohq.com:10000/app12345678

Answer 2

var mongoUri = process.env.MONGOLAB_URI || 
    process.env.MONGOHQ_URL || 
    'mongodb://localhost/mydb'; 

此行应该已经是正确的，而无需改变任何东西。只要其中一个值存在，代码就会短路，因此只有在环境变量中不存在MONGOLAB_URI或MONGOHQ_URL时才使用“mongodb：// localhost/mydb”。

这就是说，机会是一个给定的Heroku应用程序没有使用两个MongoDB提供程序，所以它是有道理的，只包括你打算使用的变量名称。我的应用程序，例如，有：

var mongoUri = process.env.MONGOLAB_URI || 'mongodb://localhost/test' 

Answer 3

首先检查你的NODE_ENV环境

$ heroku config 
=== ### Config Vars 
MONGODB_URI:   mongodb://heroku_lhwpq2p3:sdvsdvsdvds@sdvsdv.mlab.com:dsvsd/heroku_lsdv 
NODE_ENV:    production 
NPM_CONFIG_PRODUCTION: true 

你把变种名称

mongoUri = process.env.MONGOLAB_URI || localhost:.. 

应该是：

var mongoUri = process.env.MONGODB_URI || localhost:.. 

如果错误仍然存​​在，那么你需要从发展NODE_ENV环境变量设置为生产，如：

$ heroku config:set NODE_ENV="production" 
$ heroku config:set NPM_CONFIG_PRODUCTION=true