On Thu, Dec 12, 2013 at 6:54 PM, Grant <emailgr...@gmail.com> wrote:
> I'm about to embark on this (perilous?) journey and I'm wondering if
> anyone would make a comment on any of the questions in the last
> paragraph below. This is basically my plan for setting up a bunch of
> systems (laptops) in an office which are hardware-identical to my own
> laptop and creating a framework to manage them all with a bare minimum
> of time and effort.
>
> Thanks,
> Grant
>
>
>>>>>>> I see what you desire now - essentially you want to clone your laptop
>>>>>>> (or big chunks of it) over to your other workstations.
>>
>> I've been working on this and I think I have a good and simple plan.
>>
>> My laptop roams around with me and is the "master" system. The office
>> router is the "submaster" system. All of the other office systems are
>> "minion" systems. All of the systems are 100% hardware-identical
>> laptops. All of the minions are 100% software-identical.
>>
>> I install every package that any system needs on the master and create
>> an SSH keypair. The only config files that change from their state on
>> the master are: /etc/conf.d/hostname, /etc/conf.d/net,
>> /etc/ssh/sshd_config, /etc/shorewall/*. I write comments in those
>> files which serve as flags for scripted changes.
>>
>> I write a script that is run from the master to the submaster, or from
>> the submaster to a minion. If it's the former, rsync / is run with
>> exceptions (/usr/portage, /usr/local/portage, /var/log, /tmp, /home,
>> /root but /root/.ssh/id_rsa_script* is included), my personal user is
>> removed, a series of workstation users are created with useradd -m,
>> services are added or removed from /etc/runlevels/default, and config
>> files are changed according to comment flags. If it's the latter,
>> rsync / is run without exceptions, services are added or removed from
>> /etc/runlevels/default, and config files are changed according to
>> comment flags.
>>
>> All user info on the submaster and minions would be effectively reset
>> whenever the script is run and that's fine. Root logins would have to
>> be allowed on the submaster and minions but only with the SSH key.
>> There are probably more paths to exclude when rsyncing master to
>> submaster.
>>
>> That's it. No matter how numerous the minions become, this should
>> allow me to keep everything running by administrating only my own
>> system, pushing that to the submaster, and having the submaster push
>> to the minions. I've been going over the nitty-gritty and everything
>> looks good.
>>
>> What do you think? Is there anything inherently wrong with rsyncing /
>> onto a running system? If there are little or no changes to make,
>> about how much data would actually be transferred? Is there a better
>> tool for this than rsync? I know Funtoo uses git for syncing with
>> their portage tree.
>>
>> - Grant
>
Only thing that comes immediately to mind in rsyncing an overwrite of
/ is that any process that's running that goes looking for libraries
or other data after the rsync pulls the rug out from beneath it might
behave erratically, crash, kick a puppy, write arbitrary data all over
your drive. Also, it's somewhat important to be careful about the
various not-really-there mounts, /dev, /sys, /proc... /run's probably
touchy too, and /var has a few pieces that might be in use mid-sync
and choke something along the way. My idea on that would be... build
an initramfs that:
1) boots to a script
a) warns the user that it's hungry and that feeding it will be
dangerous to any non-backed-up data, with prompt
b) warns the user again, with prompt ('cause watching an rsync roll
by that eats that document you just spent 3 weeks on isn't fun)
2) mounts / in a working directory
3) rsyncs the new data from the sub-master
4) kicks off a script to update a hardware keyed (mac address is good
for this) set of settings (hostname, etc)
5) reboots into the new system.
For extra credit... sync /home back to the sub-master to prevent
overfeeding the beast.
--
Poison [BLX]
Joshua M. Murphy
