12

They say that Apache's mod_rewrite is the swiss-army knife of URL manipulation, but can it do this?

Lets say I want to add a new application to my Apache webserver, where the only configurable option of the app is a port number.

I want to use & give out URLs of the form "http://hostname.example.com/app" rather than "http://hostname.example.com:8080". This would ensure that clients would be getting through the institution's firewall as well, and it's generally tidier.

My application includes absolute URIs in php, javascript and css, so I want to prepend my own root location to the URI in the applications internal links. I have no access to DNS records and so can't create another name-based virtual server.

Using Apache's mod_rewrite and mod_proxy modules, I can transparently redirect a client to the correct home-page of the application. But links within that homepage don't point a client to links relative to the new base URL.

So, what's the best way of proxying a request to an application that is listening on a specific port?

For example, if I had an application listening on port 8080, I could put this in my Apache configuration:-

<VirtualHost *:80> SSLProxyEngine On ServerName myhost.example.com RewriteEngine On UseCanonicalName On ProxyVia On <Location "/application"> RewriteRule ^/application/?(.*) http://localhost:8080/$1 [P,L] </Location> </VirtualHost>

This would work fine if the application didn't use absolute URLs, but it does. What I need to do is rewrite URLs that are returned by the application's css, javascript and php.

I've looked at the ProxyPass and ReverseProxyPass documentation, but I don't think these would work..?

I've also come across Nick Kew's mod_proxy_html, but this isn't included in the standard Apache Distribution, and my institution's webserver seems to have been fine for years without it.. Other than trawling manually (or using a grep -r | sed type expression) through the application's source code, or using this 3rd party add-on, are there any other ways to go about this?

Could I perhaps use some of the internal server variables in a mod_rewrite rule? For example a rewrite rule based on ’HTTP_REFERER'?

Improve this question
2
  • 2
    You need mod-proxy-html, because internal links in webpages might point outside application/, if they begin with / (they are not fixable by proxy, because e.g. /img/abc request is ambiguous without context: application/img/abc or really /img/abc). Cannot you fix the app to use only relative links? Commented Sep 24, 2011 at 12:16
  • Thought I replied to this... :S The apps in question are not directory based (daemon applications that listen on their own port) and don't refer to anything outside of their respective root directories. I did try fixing all of the absolute URIs in one app (pathway tools), but this just killed the app. This was also a lot of work, and would need to be repeated should an update replace anything important (some of which could be distributed as binary and thus would be uneditable; no doubt why this app broke). Ta tho :) Commented Sep 26, 2011 at 15:22

1 Answer 1

Reset to default
15

Using mod_proxy would work just fine. For instance, I mapped https://localhost/yalla/ to point to a subdirectory of my webserver:

LoadModule proxy_module modules/mod_proxy.so ProxyRequests On <Proxy *> Order deny,allow Allow from localhost </Proxy> ProxyPass /yalla/ http://yalla.ynfonatic.de/tmp/

If you implement this, you'll note that the pictues of the directory-listing aren't visible; this is because they're below the /tmp/ directory on the remote server, hence not visible.

So, in your case you'd do:

LoadModule proxy_module modules/mod_proxy.so ProxyRequests On <Proxy *> Order deny,allow Allow from localhost # Or whatever your network is if you need an ACL </Proxy> ProxyPass /app/ http://hostname.example.com:8080/

Like with everything in Apache configuration, watch those trailing slashes when referring to directories.

Good luck! Alex.

Improve this answer
Sign up to request clarification or add additional context in comments.

4 Comments

Looks like this could work. Ta! Was looking at mod_proxy this morning actually, to see about auto-proxying my home network through the uni's one.. That's completely different functionality from this though. Will let you know how I get on. Cheers! Alex
This seems to drop preflight options requests
@nathan For that you might need some mod_rewrite sauce; I never stumbled upon that error, but a quick search revealed this link: songbard.wordpress.com/2011/05/27/… - not sure, if that helps, but feedback is welcome. YMMV.
ProxyRequests on seems a dangerous mistake: httpd.apache.org/docs/current/mod/mod_proxy.html#proxyrequests

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.