Apache反向代理将html标记添加到标头

Question

我的反向代理工作正常，但我想在代理接收的标头中添加一个html标记。我将如何解决这个问题，我尝试了数字方法，但无法使其正常工作。

<VirtualHost *:80>
    ServerAdmin webmaster@mydomain.ca
    #DocumentRoot "/var/wwwroot/mydomain.ca"

RewriteEngine On
##want to add tag in head <custom_tag> 

  ProxyPreserveHost Off
  ProxyPass        /  http://www.mydomain.com/
  ProxypassReverse /  http://www.mydomain.com/
    ServerName mydomain.ca
ServerAlias www.mydomain.ca



     Include "dontlog.conf"
    ErrorLog "/var/wwwroot/mydomain.ca/error.log"
    CustomLog "/var/wwwroot/mydomain.ca/access.txt" combined env=!dontlog
</VirtualHost>