Apache Traffic Server GeoIP ACLs
================================

This is a simple ATS plugin for denying (or allowing) requests based on the
source IP geo-location. Currently only the Maxmind APIs are supported, but
we'd be happy to other other (open) APIs if you let us know.


Building
========

The build and installation requires a full installation of Apache Traffic
Server v3.0.0 or later. A prerequisite for this is an installation of the
MaxMind GeoIP libraries and include files. E.g. GeoIP-devel.

    
Configuration
=============

Once installed, there are three primary use cases, which we will discuss in
details. Note that in all configurations, the first plugin parameter must
specify what the matches should be applied to. Currently, only one rule set
is supported, for Country ISO codes. This is specified with a parameter of

   @pparam=country


Future additions to this plugin could include other regions, such as city,
state, continent etc.

The three typical use cases are as follows:

1. Per remap configurations, applicable to the entire remap rule. This is
useful when you can partition your content so that entire prefix paths
should be filtered. For example, lets assume that http://example.com/music
is restricted to US customers only, and everything else is world wide
accessible. In remap.config, you would have something like

    map http://example.com/music http://music.example.com \
        @plugin=geoip_acl.so @pparam=country @pparam=allow @pparam=US

    map http://example.com  http://other.example.com

2. If you can not partition the data with a path prefix, you can specify a
separate regex mapping filter. The remap.config file might then look like

    map http://example.com http://music.example.com \
        @plugin=geoip_acl.so @pparam=country @pparam=regex::/etc/music.regex


where music.regex is a format with PCRE (perl compatible) regular
expressions, and unique rules for match. E.g.

    .*\.mp3	 allow	US
    .*\.ogg	 deny	US


Note that the default in the case of no matches on the regular expressions
is to "allow" the request. This can be overriden, see next use case.


3. You can also combine 1) and 2), and provide defaults in the remap.config
configuration, which then applies for the cases where no regular expressions
matches at all. This would be useful to override the default which is to
allow all requests that don't match. For example


    map http://example.com http://music.example.com \
        @plugin=geoip_acl.so @pparam=country @pparam=allow @pparam= US \
        @pparam=regex::/etc/music.regex 


This tells the plugin that in the situation where there is no matching
regular expression, only allow requests originating from the US.


Finally, there's one additional parameter option that can be used:

    @pparam=html::/some/path.html


This will override the default reponse body for the denied responses with a
custom piece of HTML. This can be useful to explain to your users why they
are getting denied access to a particular piece of content. This
configuration can be used with any of the use cases described above.
