3

I have a web application running on a tomcat server which is "behind" an Apache httpd server and I am using mod_proxy to forward requests from the httpd to the tomcat server. The httpd server is using mod_auth_tkt for authentication, which stores the info about the user in the environment variable REMOTE_USER. I pass this variable from the httpd to the tomcat server using mod_rewrite, saving it as a header (X-Forwarded-User).

The ProxyPass is set up as

httpd_server/app/ -> tomcat_server/app/

this is the vhost.conf:

<Location />
    RewriteEngine On
    RequestHeader unset X-Forwarded-User
    RewriteCond %{LA-U:REMOTE_USER} (.+)
    RewriteRule .* - [E=RU:%1,NS]
    RequestHeader add X-Forwarded-User %{RU}e
</Location>

<IfModule mod_proxy.c>
        ProxyPreserveHost On
        <Proxy *>
                Order deny,allow
                Allow from all
        </Proxy>
        ProxyPass               /app/       http://127.0.0.1:8084/app/
        ProxyPassReverse        /app/       http://127.0.0.1:8084/app/
</IfModule>

And this works perfectly. But if try to change the ProxyPass to

httpd_server/ -> tomcat_server/app/

So changing the the vhost.conf to:

ProxyPass               /       http://127.0.0.1:8084/app/
ProxyPassReverse        /       http://127.0.0.1:8084/app/

Then the header (X-Forwarded-User) ends up empty (null) on the web application.

After further investigation I found out that if I try to forward a different variable, for example REMOTE_PORT (or even a string), everything works correctly for both configurations (The app recieves the header correctly).

Is there any obvious mistake why the forwarding of REMOTE_USER does not work when proxy-ing from the root directory? Did I miss something or could this be a mod_auth_tkt issue?

Your Answer

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.

Browse other questions tagged or ask your own question.