[Server-devel] Understanding the network scripts on F7-based XS

[Martin Langhoff]

Our current network migration scripts are reportedly build on
interfaces that are F7 specific. To reimplement them on F9, we need to
understand what they do.

Jerry is knowledgeable in F9's networking and has offered help with
the port. The first step is to understand what the current scripts do
- separated from the how. So I will try to outline the design and
behaviour of the current scripts.

The first point of entry is reading the whole "Networking" section in
this page. All of it :-)
http://wiki.laptop.org/go/XS_Configuration_Management#Networking

It introduces

 - network_config
 - principal_config
 - auxiliary_config

These scripts deal with

 - Configuring network interfaces
   - 1 NIC scenarios have eth0 as WAN / 2 NIC scenarios add eth1 as LAN
   - Can set preferential MAC address prefix for some interfaces. This
can be used by the NOC team to get the right NIC setup as eth0.
   - Sets up the pair of ethX/mshY interfaces that are attached to
every Active Antenna.
   - Sets up all the bridges between the interfaces considered LAN
   - Picking non-conflicting IP addresses for auxiliary servers.
   - Sets the router address for auxiliary servers
 - Very rough service chkconfig configuration for the auxiliary vs
primary servers
 - Rough firewall config for primary/auxiliary servers

The top of each script - after the GPL - has an extensive comment
explaining what it does. And after that, you can scroll down to the
'main' block -- I find both very readable. The scripts are here if you
don't have a checkout
http://dev.laptop.org/git?p=projects/xs-config;a=tree;f=fsroot.olpc.img/etc/sysconfig/olpc-scripts;h=dada76a2869dc95c5f538adfa45a2e538dc1d998;hb=HEAD

The 3 scripts make sense to me - - I would attack it with a
get-to-work-stable-on-f9 focus, roughly:

 - Can we make the networking configuration work in a stable manner on
F9? Do we need to hook into the events infrastructure so when an
ethernet cable gets plugged into an if we do the right thing? Could we
make it so that we autodetect and configure an AA on usb connection?

 - Can we allow additional MAC prefix preferences to be read from an
optional config file so that a NOC team can override things easily?

 - Can we consolidate the code / remove duplication? (trivial ;-) )

 - Can we remove the service mgmt from it? :-)

Jerry, does that help? It is meant as a complement while reading the
src... BTW, I am tracking this on https://dev.laptop.org/ticket/7672

cheers,



m
-- 
 martin.langhoff at gmail.com
 martin at laptop.org -- School Server Architect
 - ask interesting questions
 - don't get distracted with shiny stuff - working code first
 - http://wiki.laptop.org/go/User:Martinlanghoff