[ale] Copying config files to DHCP peer

[Joey Kelly]

On Thursday, December 19, 2019 10:58:03 AM Todor Fassl via Ale wrote:
> I have been running peered ISC dhcp servers for years. The problem is
> that you need copies of the config files on both machines. Say you want
> to assign an IP address to a new machine. You add a stanza to a config
> file but then you then have to get a copy of the modified config file to
> the peer. If you forget to do that, you are going to screw things up
> pretty badly.

So write a wrapper that fetches your stanzas or the complete config file, pushes 
them to the servers, then restarts the servers. ansible/puppet can be your 
friend here.

--Joey


> Other people in my department occasionally need to make these config
> changes. So I need a way to guarantee that the config files get copied
> over. Googling showed me lots of articles on configuring a peer in
> isc-dhcp but only one on syncing the config files. That person was doing
> it via rsync and a script in cron.hourly.
> 
> What I have done, at least for now, is to replace the init script with
> my own script. This script uses an ssh key to copy the files to the peer
> and then restarts dhcp on the peer. If somebody types "service dhcp
> restart", it runs my script. But now with systemd, it is going to be harder.
> 
> Fortunately, for now, my co-workers are still typing "service bind9
> restart" and the like. So "service dhcp restart" is not a problem --
> yet. But if somebody types "systemctl restart isc-dhcp-server", it is
> not going to work.
> 
> 
> Its interesting that bind9 and slapd handle this under the covers.

-- 
Joey Kelly
Minister of the Gospel and Linux Consultant
http://joeykelly.net
504-239-6550