Layman
Layman can be used to use external portage directories via svn and more different programs and integrate all into portage.
Using Layman
At first we need to install layman:
emerge -av layman
Create Own Layman Repository
At first create a virtual host in your apache config and place there a config file for layman. overlay.xml Now add to the file /etc/layman/layman.conf the line:
overlays : http://www.gentoo.org/proj/en/overlays/layman-global.txt
http://overlay.idefix.lan/overlay.xml
Edit /etc/make.conf
source /usr/portage/local/layman/make.conf
Now we create the xml file on the server:
<?xml version="1.0" ?>
<layman>
<overlay
contact = "idefix@fechner.net"
name = "idefix"
src = "http://overlay.idefix.lan/"
type = "svn"
status = "official">
<link>
http://overlay.idefix.lan/svn/overlay/trunk/
</link>
<description>
Idefix overlay.
</description>
</overlay>
</layman>