MEAN STACK APP部署HEROKU问题 MongoNetworkError: failed to connect to server

Question

找不到连接到 MongoDB 以部署应用程序的方法。给我一个错误 " MongoNetworkError: failed to connect to server [localhost:27017] on first connect [Error: connect ECONNREFUSED 127.0.0.1:27017" 什么地方出错了？连接到8080服务器还是报错。

app.js

    const MONGODB_URI = 'mongodb://localhost:27017/members'

    mongoose
      .connect(
        MONGODB_URI,
        { useNewUrlParser: true },
        { useMongoClient: true }
      )
      .then(() => console.log('MongoDB Connected'))
      .catch(err => console.log(err))

    var Users = require('./routes/users')

    app.use('/users', Users)
    const Post = require('./model/post')
    //API end point for fetching the list of blog posts. Since for db Mongo is used, Mongoose client added to connect the db with the app.
    app.post('/api/post/getAllPost', (req, res) => {
        mongoose.connect(url, { useMongoClient: true } , function(err){
          console.log(err - 'error here')
            if(err) throw err;
            console.log("connection established successfully")
            Post.find({},[],{ sort: { _id: -1 } },(err, doc) => {
                if(err) throw err;
                return res.status(200).json({
                    status: 'success',
                    data: doc
                })
            })
        });
    })

    app.listen(port, function() {
      console.log('Server is running on port: ' + port)
    })

Answer 1

首先尝试通过 mongodb compass 社区访问您的数据库，您可能会得到一个连接字符串来本地连接到您的数据库..

mongoose.connect('mongodb://localhost:27017/supercampus?readPreference=primary&appname=MongoDB%20Compass%20Community&ssl=false',
{ useNewUrlParser: true,useUnifiedTopology: true },
(err,res)=>{
   if(err) console.log(err)
   else{
    console.log("connected")
   }    
})

对于 heroku 部署，您需要一个免费的在线选项，例如 mongodb atlas