502：来自 Ubuntu 18.04 和 Apache2 上的 Express 应用程序的代理错误

Question

我想创建一个简单的Express &Ubuntu 18.04上的Node应用程序，应该像API一样运行。问题是，每当尝试访问url时，我只得到502错误。下面是用于配置Apache和express应用本身的代码，以及来自日志的条目。

App.js

const express = require('express')
const http = require('http')
const cors = require('cors')
const app = express()
app.use(cors())
app.enable('trust proxy')
const port = 3500
app.get('/', function (req, res) {
console.log('asdfasdf')
})
http.createServer(app).listen(port, () => {
console.log('Running http server on port %s', port);
});

Apache配置(非ssl):

<VirtualHost *:80>
ServerAdmin webmaster@localhost
DocumentRoot /var/www/node2.domain.io
ServerName node2.domain.io
ServerAlias www.node2.domain.io
ProxyRequests Off
ProxyPreserveHost On
ProxyVia Full
<Proxy *>
Require all granted
</Proxy>
<Location />
ProxyPass https://127.0.0.1:3500/
ProxyPassReverse https://127.0.0.1:3500/
</Location>
<Directory /var/www/node2.domain.io>
Options Indexes FollowSymLinks
AllowOverride All
Require all granted
</Directory>
RewriteEngine on
RewriteCond %{SERVER_NAME} =node2.domain.io [OR]
RewriteCond %{SERVER_NAME} =www.node2.domain.io
RewriteRule ^ https://%{SERVER_NAME}%{REQUEST_URI} [END,NE,R=permanent]
</VirtualHost>

Apache config (SSL):

</VirtualHost>
</IfModule>
<IfModule mod_ssl.c>
<VirtualHost *:443>
ServerAdmin webmaster@localhost
DocumentRoot /var/www/node2.domain.io
ServerName node2.domain.io
ServerAlias www.node2.domain.io
SSLProxyEngine On
SSLProxyVerify none
SSLProxyCheckPeerCN off
SSLProxyCheckPeerName off
SSLProxyCheckPeerExpire off
ProxyRequests Off
ProxyPreserveHost On
ProxyVia Full
<Proxy *>
Require all granted
</Proxy>
<Location />
ProxyPass https://127.0.0.1:3500/
ProxyPassReverse https://127.0.0.1:3500/
</Location>
<Directory /var/www/node2.domain.io>
Options Indexes FollowSymLinks
AllowOverride All
Require all granted
</Directory>
SSLCertificateFile /etc/letsencrypt/live/node2.domain.io/fullchain.pem
SSLCertificateKeyFile /etc/letsencrypt/live/node2.domain.io/privkey.pem
Include /etc/letsencrypt/options-ssl-apache.conf
</VirtualHost>
</IfModule>

日志条目:

AH01102: error reading status line from remote server 127.0.0.1:3500, referer: https://node2.domain.io/

^这个x 200

作为旁注，当我启动前端React应用程序时，它会正常工作。

Answer 1

在您的代码中，您从不返回对请求的响应:

app.get('/', function (req, res) {
console.log('asdfasdf')
})

当我们调用/时，您告诉express执行console.log('asdfasdf')而不执行其他操作。

返回像这样的东西，你将得到你的响应:

app.get('/', function (req, res) {
console.log('asdfasdf')
res.send('ok') // <-- add this line
})

另外，如果你想创建一个API，你可能想返回JSON响应，所以你可以使用Express的res.json()方法:

app.get('/', function (req, res) {
console.log('asdfasdf')
res.json({
name: 'toto',
foo: 'bar'
})
})

Answer 2

我已经替换了http。createServer (/* . .*/)与app.listen(port)，它现在工作了。