DESCRIPTION

Apache2::ModProxyPerlHtml is a mod_perl2 replacement of the Apache2 module mod_proxy_html.c use to rewrite HTML links for a reverse proxy.

Apache2::ModProxyPerlHtml is very simple and has far better parsing/replacement of URL than the original C code. It also support meta tag, CSS, and javascript URL rewriting and can be use with compressed HTTP. You can now replace any code by other, like changing images name or anything else.

AVAIBILITY

You can get the latest version of Apache2::ModProxyPerlHtml from CPAN (http://search.cpan.org/).

PREREQUISITES

You must have Apache2, mod_perl2 and IO::Compress::Zlib perl module installed.

You also need to install the mod_proxy Apache module. See documentation at http://httpd.apache.org/docs/2.0/mod/mod_proxy.html

INSTALLATION

        % perl Makefile.PL
        % make && make install

APACHE CONFIGURATION

Here is the DSO module loading I use:

    LoadModule deflate_module modules/mod_deflate.so
    LoadModule headers_module modules/mod_headers.so
    LoadModule proxy_module modules/mod_proxy.so
    LoadModule proxy_connect_module modules/mod_proxy_connect.so
    LoadModule proxy_ftp_module modules/mod_proxy_ftp.so
    LoadModule proxy_http_module modules/mod_proxy_http.so
    LoadModule ssl_module modules/mod_ssl.so
    LoadModule perl_module  modules/mod_perl.so

Here is the reverse proxy configuration I use :

    ProxyRequests Off
    ProxyPreserveHost Off
    ProxyPass       /webmail/  http://webmail.domain.com/
    ProxyPass       /webcal/  http://webcal.domain.com/
    ProxyPass       /intranet/  http://intranet.domain.com/

    PerlInputFilterHandler Apache2::ModProxyPerlHtml
    PerlOutputFilterHandler Apache2::ModProxyPerlHtml
    SetHandler perl-script
    PerlSetVar ProxyHTMLVerbose "On"
    LogLevel Info

    # URL rewriting
    RewriteEngine   On
    RewriteLog      "/var/log/apache/rewrite.log"
    RewriteLogLevel 9
    # Add ending '/' if not provided
    RewriteCond     %{REQUEST_URI}  ^/mail$
    RewriteRule     ^/(.*)$ /$1/    [R]
    RewriteCond     %{REQUEST_URI}  ^/planet$
    RewriteRule     ^/(.*)$ /$1/    [R]
    # Add full path to the CGI to bypass the index.html redirect that may fail
    RewriteCond     %{REQUEST_URI}  ^/calendar/$
    RewriteRule     ^/(.*)/$ /$1/cgi-bin/wcal.pl    [R]
    RewriteCond     %{REQUEST_URI}  ^/calendar$
    RewriteRule     ^/(.*)$ /$1/cgi-bin/wcal.pl     [R]

    <Location /webmail/>
        ProxyPassReverse /
        PerlAddVar ProxyHTMLURLMap "/ /webmail/"
        PerlAddVar ProxyHTMLURLMap "http://webmail.domain.com /webmail"
        # Use this to disable compressed HTTP
        #RequestHeader   unset   Accept-Encoding
    </Location>

    <Location /webcal/>
        ProxyPassReverse /
        PerlAddVar ProxyHTMLURLMap "/ /webcal/"
        PerlAddVar ProxyHTMLURLMap "http://webcal.domain.com /webcal"
    </Location>

    <Location /intranet/>
        ProxyPassReverse /
        PerlAddVar ProxyHTMLURLMap "/ /intranet/"
        PerlAddVar ProxyHTMLURLMap "http://intranet.samse.fr /intranet"
        PerlAddVar ProxyHTMLURLMap "/intranet/webmail /webmail"
        PerlAddVar ProxyHTMLURLMap "/intranet/webcal /webcal"
    </Location>

Note that this example set filterhandlers globally, you can set it in any <Location> part to set it locally and avoid calling this Apache module globally.

If you want to rewrite some code on the fly, like changing images filename you can use the perl variable ProxyHTMLRewrite under the location directive as follow:

    <Location /webmail/>
        ...
        PerlAddVar ProxyHTMLRewrite "/logo/image1.png /images/logo1.png"
        ...
    </Location>

this will replace each occurence of '/logo/image1.png' by '/images/logo1.png' in the entire stream (html, javascript or css). Note the this kind of substitution is done after all other proxy related replacements.

In certain condition some javascript code will be replaced by error, for example:

        imgUp.src = '/images/' + varPath + '/' + 'up.png';

will be rewritten like this:

        imgUp.src = '/URL/images/' + varPath + '/URL/' + 'up.png';

To avoid the second replacement, write your JS code like that:

        imgUp.src = '/images/' + varPath + unescape('%2F') + 'up.png';

BUGS

Apache2::ModProxyPerlHtml is still under development and is pretty stable. Please send me email to submit bug reports or feature requests.

COPYRIGHT

AUTHOR

Apache2::ModProxyPerlHtml was created by :

        Gilles Darold
        <gilles at darold dot net>

and is currently maintain by me.

CPAN RT