NAME

Director HowTo

SYNOPSIS

Apache::Mogile::Dispatch allows you to set 'directors' which decide if a given uri is to be handled through mogile or a set of static servers. This is makes it very easy to migrate gradually to using MogileFS.

FUNCTIONS

There are two functions that are required with every director. They are memcache_key and get_direction.

memcache_key

This function returns the memcache key to use. If you do not plan on using memcache you must include this anyway.

get_direction

This function returns a hashref containing several keys that are used by Apache2::Module::Dispatch to determine if mogile is to be used or not.

mogile

Values: 0, 1, undef

reproxy

Values: url, undef

canonical_domain

Values: hostname, undef

If this value is returned than it is prepended to the filename when looking up mogile files.

GET /index.html
HOST: socklabs.com

if ($canonical_domain) # file: /socklabs.com/index.html
if (! $canonical_domain) # file: /index.html

EXAMPLE

The following is a simple example of a director. It uses the request hostname as the memcache key and get_direction returns processed yaml. See t/FakeDispatch.pm for more information.

## -- http.conf
</Perl>
  use SocklabsDirector;
</Perl>

## -- SocklabsDirector.pm
package SocklabsDirector;

use strict;
use warnings;

use APR::Table ();
use APR::SockAddr ();
use Apache2::RequestRec ();
use Apache2::RequestUtil ();
use Apache2::Connection ();
use Apache2::Filter ();
use Apache2::RequestRec ();
use Apache2::Module;
use Apache2::CmdParms ();
use Apache2::Directive ();
use Apache2::Log ();
use Apache2::URI ();
use Apache2::Const -compile => qw(DECLINED OK OR_ALL RSRC_CONF TAKE1 RAW_ARGS NO_ARGS DONE NOT_FOUND);

use LWP::UserAgent;
use YAML::Syck;

use constant FAKEDIRECTOR_URL => 'http://localhost:8529/FakeDispatch';

sub memcache_key {
    my ($self, $r, $config) = @_;
    return $r->hostname;
}

sub get_direction {
    my ($self, $r, $config) = @_;
    my $ua = LWP::UserAgent->new;
    my $url = FAKEDIRECTOR_URL . '?domain=' . $r->hostname;
    my $response = $ua->get($url);
    if ($response->is_success) {
        return Load($response->content);
    }
    return 0;
}

1;

IDEAS

• hostname based directing

• uri/location based directing