Is it possible to match more than one regular expression with a single rule?

Question

I have a production, testing, and development server for a site that I maintain. All three servers are running Apache 2.2.16 on Debian 6 GNU/Linux. I have set up a new version of our company site on the testing server, and my team determined it to be stable enough to move to production. However, I want to make this transition as seamless as possible. I would like to be able to forward requests at production server so they are handled by the testing server. This way, I can test out this new implementation without making any complex configuration changes on the production server.

Ideally, I can use Apache's mod_proxy module to set up a reverse proxy so that I can serve pages directly from the testing server to production clients. I read the documentation at http://httpd.apache.org/docs/2.0/mod/mod_proxy.html, which was very helpful to me. I enabled mod_proxy and mod_proxy_http, then I set the following rules on my development server.

<VirtualHost *:80>
    ServerName dev.example.com
    # ... other <VirtualHost>-specific settings ...

    ProxyRequests Off
    <Proxy *>
        Order deny,allow
        Allow from all
    </Proxy>
    ProxyPass / http://test.example.com/
    ProxyPassReverse / http://test.example.com

    # ... various <Directory> directives ...
</VirtualHost>

This worked very well. When I accessed the development server, the site served all pages directly from the testing server, and it appeared as if these responses came directly from the server I had connected to. Moreover, these requests were rather snappy, and I was able to make both GET and POST requests as if I was talking directly to the testing server.

Unfortunately, this does not fit all of my needs. Since the testing server only runs Apache with a new version of the site, I cannot host webmail or userdirs from the testing server. These requests must be handled by the production server.

I want my production server to be able to use the reverse proxy for all pages except /webmail and the user directories (any directory starting with a tilde). In theory this is possible with <ProxyMatch> directive. However, I do not have sufficient regex-fu to do this. Is there a single rule capable of excluding both of these types of requests from being sent to the proxy server?

Bonus points: I am looking for a good introductory guide to PCRE's, so that I can write my own rules. Does anyone have a recommendation for a regex newbie?

score 1 · Answer 1 · answered Jul 04 '11 at 12:18

You can't have more than one regular expression in the directive - but you can have a regular expression which implements complex logic:

/http:\/\/test.example.com\/\/(?!webmail)/

I'd recommend the O'Reilly book Mastering regular Expressions but its not an introductory text.

There's lots of online material to get you started. There's a basic tutorial here. But I'd suggest getting a good book on the topic too (but I can't recommend on from personal experience).

Is it possible to match more than one regular expression with a single rule?

1 Answers1