Debian – apache2 mod_proxy in conjuction with mod_rewrite not working as expected

amazon-web-servicesapache-2.2debianmod-proxymod-rewrite

I am trying to use mod_rewrite in conjunction with mod_proxy to deliver contents from a different internal webserver (http://webserver.internal.com/foo) through a (fake) subdirectory "foo" (http://example.com/foo).

Using mod_proxy with ProxyPass directive I was able to do this already with this configuration in /etc/apache2/mods-enabled/proxy.conf

ProxyPass /foo http://webserver.internal.com/foo
ProxyPassReverse /foo http://webserver.internal.com/foo

Now I have the additional requirement to enforce rewriting all requests to dynamic resources from http://example.com to https:// example.com, which again standalone works as well, but not together with the ProxyPass rules stated above. It seems the proxy configuration has always precedence over the rewrite rules.

As as far as my research has shown me utilizing mod_proxy from within my rewrite rules should be as easy as adding

RewriteCond %{REQUEST_URI} ^/foo
RewriteRule ^/foo(.*) http://webserver.internal.com/foo$1 [P]

to my rewrite rules and the rewritten URI will be automatically passed through mod_proxy. I turned on RewriteLog with a LogLevel of 9, but I am not able to see the matching of ^/foo and execution of the following Proxy-RewriteRule afterwards. There is nothing like go-ahead proxy, or any mention of proxying, not even an error entry within the RewriteLog.

I have the following proxy modules activated in my apache2 configuration

proxy 
proxy_connect 
proxy_http

I tried to test my RewriteCondition with another example – this time matching ^/foo and redirecting to www.google.com

RewriteCond %{REQUEST_URI} ^/foo
RewriteRule ^(.*)$ http://www.google.com/ [R=302,L]

which is working as intended, with the following results in the RewriteLog:

RewriteCond: input='/foo' pattern='^/foo' => matched
rewrite 'foo' -> 'http://www.google.com/'
explicitly forcing redirect with http://www.google.com/
escaping http://www.google.com/ for redirect
redirect to http://www.google.com/ [REDIRECT/302]

Following below is the rewrite configuraiton I am using within a directory section of my vhost.

    <Directory /my/app/webroot >
            RewriteEngine On
            RewriteBase /

            #redirect all http requests to https - WORKING
            # incoming request was forwarded as http from ELB
            RewriteCond %{HTTP:X-Forwarded-Proto} =http
            # avoid https rewriting for static files like images, javascripts, files and templates
            # for folders /img, /js, /css, /files and /templates under webroot
            RewriteCond %{REQUEST_URI} !^/(img|js|css|files|templates)
            RewriteRule (.*) https:// example.com%{REQUEST_URI}  [R=301,L]

            # requests to /foo *should* be handled by mod_proxy - NOT WORKING
            RewriteCond %{REQUEST_URI} ^/foo
            RewriteRule ^/foo(.*) http://webserver.internal.com/foo$1 [P]

            #pretty URLS for web-application - WORKING
            RewriteCond %{REQUEST_FILENAME} !-d
            RewriteCond %{REQUEST_FILENAME} !-f
            RewriteRule ^(.*)$ index.php?url=$1 [QSA,L]
    </Directory>

The machine in question is a basic debian server installation, with apache2 and php and is hosted in the amazon cloud behind a Elastic Load Balancer.

If you read down this far – first of all – thank you for patience!

It would be great if somebody could help with resolving this problem. Maybe it is just a little think I've overseen.

Many thanks in advance!

Best Answer

Wrong:

RewriteRule ^/foo(.*) http://webserver.internal.com/foo$1 [P]

Сorrectly:

RewriteRule ^foo(.*)$ http://webserver.internal.com/foo$1 [P,L]

Will be a problem, write to email.

Related Solutions

Tomcat – Apache2 – mod_expire and mod_rewrite not working in httpd.conf – serving content from tomcat

Probably the ProxyPass / directive you have in your config routes all requests to the Tomcat backend, bypassing all your mod_rewrite directives. You can try to remove the ProxyPass directive and use RewriteRule with the [P] flag after your other rewrites:

mod_rewrite: P|proxy

For the expire headers the situation is worse — in another similar question a solution was not found.

Option +FollowSymLinks would be needed for using mod_rewrite in .htaccess files; in your case it is not required, because you can put everything in the Apache config. Moving rules from config to .htaccess is pointless and can only make things slower. However, there is an important difference between .htaccess and the Apache config — in .htaccess patterns in RewriteRule are matched against relative filesystem paths (which never start with /), while in the VirtualHost context these patterns are matched against the URL path after the hostname, which always starts with /. Therefore at least one of your rules is incorrect:

RewriteRule ^content/(js|css)/([a-z]+)-([0-9]+)\.(js|css)$ /content/$1/$2.$4

should be

RewriteRule ^/content/(js|css)/([a-z]+)-([0-9]+)\.(js|css)$ /content/$1/$2.$4

(note the additional slash in the beginning).

URL rewrite for subdomain with Apache and mod_proxy

Ok, I got it running...

The key elements where the following mod_rewrite conditions

    RewriteCond   %{HTTP_HOST} ^((?!www\.)[^.]+)\.example\.com$
    RewriteCond %{REQUEST_URI} ^/some.+$
    RewriteRule   ^(.+)  %{HTTP_HOST}$1  [C]
    RewriteRule   ^([^.]+)\.example\.com(.*) http://example.com:8008$2-$1 [P]
    ProxyPassReverse http://example.com/ http://example.com:8008/

The first condition tells the Apache server to catch all URLs which address a subdomain - except the subdomain www.

The second condition tells the Apache that the requested path (URI) must start with a special indicator. In my example this is "some". This is important, otherwise all css/images/js etc. falls under this rewrite condition and my tomcat wouldn't deliver all that stuff.

now there are two lines of rewrite rules. The first one matches the subdomain and save it in var $1. The second one matches the URI and saves it in $2. After the second rewrite rule I tell the system how to build up the new URL:

http://example.com:8008$2-$1 [P]

Here I redirect to the tomcat server runnning on my system. It might be ok to use an IP instead of the domain name. The [P] tells the system to use the mod_proxy to redirect the traffic.

In the last line we define a ProxyPassReverse to re-build all links in the answer-document coming from the proxy and going to the client browser - so all http://example.com:8008 anchors going back to http://subdomain1.example.com.

I had some problems with my tomcat config when using the above code. The [P] flag doesn't preserve the original host. Because of that I had to change in the tomcat server.xml the default host for my used engine:

 <Engine name="Catalina" defaultHost="example.com">

Hopefully these infos help someone at some time..

Best wishes

Best Answer

Related Solutions

Tomcat – Apache2 – mod_expire and mod_rewrite not working in httpd.conf – serving content from tomcat

URL rewrite for subdomain with Apache and mod_proxy

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