Rest api - MongoNetworkError：无法连接到服务器答案

【问题标题】：Rest api - MongoNetworkError: failed to connect to serverRest api - MongoNetworkError：无法连接到服务器
【发布时间】：2018-10-26 13:58:10
【问题描述】：

我正在尝试为 mongo db 创建一个简单的 rest api

我有一个 server.js

const express = require('express');
const mongoose = require('mongoose');
const bodyParser = require('body-Parser');

const app = express();

app.use(bodyParser.json());

const db = require('./config/keys').mongoURI;

mongoose
    .connect('mongodb://test:test123@ds241012.mlab.com:41012/test_db' ,{useNewUrlParser: true})
    .then(() => console.log('DB Connected'))
    .catch(err => console.log(err));

const port = process.env.PORT || 4000;

app.listen(port, () => console.log('Server started'));

我使用 nodemon，当我执行 npm run server 时，我会在终端（console.log）中看到“服务器已启动”

在此之后我得到以下终端输出

{ MongoNetworkError: failed to connect to server [ds241012.mlab.com:41012] on first connect [MongoNetworkError: connection 0 to ds241012.mlab.com:41012 timed out]
    at Pool.<anonymous> (/Users/cdd/Documents/_Work/cd/React/test_db/node_modules/mongodb-core/lib/topologies/server.js:564:11)
    at emitOne (events.js:116:13)
    at Pool.emit (events.js:211:7)
    at Connection.<anonymous> (/Users/cdd/Documents/_Work/cd/React/test_db/node_modules/mongodb-core/lib/connection/pool.js:317:12)
    at Object.onceWrapper (events.js:317:30)
    at emitTwo (events.js:126:13)
    at Connection.emit (events.js:214:7)
    at Socket.<anonymous> (/Users/cdd/Documents/_Work/cd/React/test_db/node_modules/mongodb-core/lib/connection/connection.js:257:10)
    at Object.onceWrapper (events.js:313:30)
    at emitNone (events.js:106:13)
    at Socket.emit (events.js:208:7)
    at Socket._onTimeout (net.js:420:8)
    at ontimeout (timers.js:482:11)
    at tryOnTimeout (timers.js:317:5)
    at Timer.listOnTimeout (timers.js:277:5)
  name: 'MongoNetworkError',
  errorLabels: [ 'TransientTransactionError' ],
  [Symbol(mongoErrorContextSymbol)]: {} }

如果我随后更新 server.js，终端将返回“服务器已启动”

gte这个输出正常吗

【问题讨论】：

标签： mongodb rest express

【解决方案1】：

如果您已经将尝试连接 mongodb 的机器的 IP 地址列入白名单，那么您收到错误的唯一可能性是防火墙阻止了它。

【讨论】：