Apache 反向代理默认会改写Request head中的host，这样会造成在应用中如果使用reqeust.getHead("host")来做绝对路径的时候存在无法连接的问题。
网上很多Apache的proxy设置都只写了ProxyPass 和 ProxyPassReverse
ProxyPass / http://172.18.100.51/
ProxyPassReverse / http://172.18.100.51/这个时候如果在应用中使用reqeust.getHead("host") 或者PHP中使用$_SERVER['HTTP_HOST'] 绝对路径来请求js或者css 就会是172.18.100.5,本地浏览器如果是在外网就无法访问了。
只需要在Apache中添加
ProxyPreserveHost On就可以解决这个问题
在Apache官方文档中关于他的描述
ProxyPreserveHost Directive
Description:Use incoming Host HTTP request header for proxy request
Syntax:ProxyPreserveHost On|Off
Default:ProxyPreserveHost Off
Context:server config, virtual host, directory
Status:Extension
Module:mod_proxy
Compatibility:Usable in directory context in 2.3.3 and later.
When enabled, this option will pass the Host: line from the incoming request to the proxied host, instead of the hostname specified in the ProxyPass line.
This option should normally be turned Off. It is mostly useful in special configurations like proxied mass name-based virtual hosting, where the original Host header needs to be evaluated bythe backend server.同理 Nginx 中也有一个类似的参数
proxy_set_header Host $host;