Automatic service announcement and discover using avahi

[Petter Reinholdtsen <pere@hungry.com>]

One long term goal in Debian Edu is to get rid of hardcoded
configuration and allow clients and servers to find each other
automatically.  One way to do it is using the Avahi system.  It is the
same mechanism used by Mac OSX to locate services.  If you want to see
what is announced in your network, install and run the avahi-discover
application.  It show a GUI list of services.

We can use this system to announce the main-server services by adding
XML files in /etc/avahi/services/.  Here is an example I created and
added to my laptop:

  <service-group>
    <name>LDAP directory service</name>
    <service protocol="any">
      <type>_ldap._tcp</type>
      <port>389</port>
    </service>
  </service-group>

Adding this file and reloading the avahi-daemon made make all clients
on the local network see the announcement.  We could add similar
announcements for NTP, NFS and all the other services on a
main-server, and change the clients to use this information to find
the services they want to use.

Happy hacking,
-- 
Petter Reinholdtsen