NextJS/Vercel/MongoDB FetchError:请求 http://localhost:3000/ap

Question

我使用NextJS对MongoDB进行API调用。当我转到 API 链接时，我看到返回的 MongoDB 查询。但是，当我尝试将该数据提取到网页时，我收到500内部服务器错误。函数日志显示以下错误：

2020-05-27T17:17:02.129Z    5a0c88b0-da63-4225-acf1-ea1d589ff438    ERROR   FetchError: request to http://localhost:3000/api/gear failed, reason: connect ECONNREFUSED 127.0.0.1:3000
at ClientRequest.<anonymous> (/var/task/node_modules/next/dist/compiled/node-fetch/index.js:1:147710)
at ClientRequest.emit (events.js:310:20)
at Socket.socketErrorListener (_http_client.js:426:9)
at Socket.emit (events.js:310:20)
at emitErrorNT (internal/streams/destroy.js:92:8)
at emitErrorAndCloseNT (internal/streams/destroy.js:60:3)
at processTicksAndRejections (internal/process/task_queues.js:84:21) {
message: 'request to http://localhost:3000/api/gear failed, reason: connect ECONNREFUSED 127.0.0.1:3000',
type: 'system',
errno: 'ECONNREFUSED',
code: 'ECONNREFUSED'
}

运行 npm run dev 时，所有代码都在本地工作，只是在托管到 Vercel 时不起作用。我只是不太明白为什么当我导航到 API 页面时它会返回 MongoDB 数据，但是当我尝试从另一个页面调用该 API 时，它无法连接。

作为参考，我使用此链接来构造我的数据库调用。

下面是失败页面的 getInitialProps 以及数据库中间件。

齿轮.jsx

import React, { Fragment } from "react"
import fetch from 'isomorphic-unfetch'
//Returned HTML here based on query. Left this part out to keep the issue simple.
export async function getServerSideProps() {
const res = await fetch('http://localhost:3000/api/gear')
const json = await res.json()
return { props: { gearArray: json } }
}
export default Gear;

API/设备.js

import nextConnect from 'next-connect';
import middleware from '../../middleware/database';
const handler = nextConnect();
handler.use(middleware);
handler.get(async (req, res) => {
let gear = await req.db.collection('gear').find({}).sort({gear: 1}).toArray();
res.json(gear);
});
export default handler;

数据库.js

import { MongoClient } from 'mongodb';
import nextConnect from 'next-connect';
const client = new MongoClient(process.env.MONGOURL, {
useNewUrlParser: true,
useUnifiedTopology: true,
});
async function database(req, res, next) {
if (!client.isConnected()) await client.connect();
req.dbClient = client;
req.db = client.db('BassTabs');
return next();
}
const middleware = nextConnect();
middleware.use(database);
export default middleware;

Answer 1

在 Vercel 上托管应用程序时，您需要将获取 URL 更改为https://my-bassist-chris.mybassistchris.now.sh/api/gear，因为这是数据现在的来源。

在本地运行应用程序时，使用localhost.