TUSCANY-3860: Add README file

git-svn-id: http://svn.us.apache.org/repos/asf/tuscany@1102413 13f79535-47bb-0310-9956-ffa450edef68

site/trunk/site-publish/updatesite/README

@@ -0,0 +1,42 @@
+Apache Tuscany Update Site:
+---------------------------
+The Apache Tuscany Eclipse update site is located under http://tuscany.apache.org/updatesite.
+It is based on the Apache Directory Studio update site, with minimal changes.
+
+The Tuscany update site consists of the following files:
+
+ +--tuscany.apache.org
+    |
+    +--updatesite
+       |
+       +--README (this file)
+       +--java
+          |
+          +--sca
+             |
+             +--1.6.2 (and later releases)
+                |
+                +--.htaccess
+                +--index.html
+                +--LICENSE
+                +--NOTICE
+                +--site--xml.html
+                +--site--xml.cgi
+                +--web
+                   |
+                   +--site.css
+                   +--site.xsl
+
+The update manager of Eclipse and the RCP application automatically tries to 
+access the site.xml to get new updates or features. Our .htaccess contains
+a rewrite rule to forward from site.xml to site--xml.cgi.
+
+The site--xml.cgi just calls Apache's mirrors.cgi to get a list of available
+mirrors.
+
+The site--xml.html is a template of the real site.xml. The url of the 
+preferred mirror determined by the cgi script is applied to this template.
+
+With this trick the update manager always gets a URL to another mirror.
+The update manager loads the features and plugins from these mirrors. So
+the mirrors must contain the features and the plugins directories.