Re: [B.A.T.M.A.N.] alfred hook to run when new information is received?

[Simon Wunderlich <sw@simonwunderlich.de>]

Hey Guido,

> Hey Simon,
> until sarcasmarec ideas come true... ;)
> [(2013/10/14) marec: d0tslash: we should release some more daemons]
> we're doing our best to convince current daemons to turn *more* evil, in
> the meanwhile
> 
> turns out, we're trying to propagate dnsmasq dhcp leases over the
> network with alfred
> [1]:
> http://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2013q4/007750.html
> 
> with the current 'alfred-facters' 5-minute cronjob (or any cronjob,
> yeah) we can send a reload signal to dnsmasq at an acceptably short
> interval. Nevertheless, something more realtime would be highly
> desirable in this case
> 
> some kind of hook inside the C code, that gets called when alfred gets
> updated information from any other node, and the hook runs a script (or
> maybe all facters in facters_dir?)
> 
> in other words, instead of polling alfred every X interval to see if
> there's any new info, make alfred react as soon as it receives
> propagated info, so that it calls facter scripts and they can use that
> info ASAP.
> 
> What do you think? Sounds useless? doable? Lightweight? Almighty?

Doable - sure. Almight - maybe. :D

How about:
 * add another parameter to the server like --update-script 
/path/to/script.sh. This could call /path/to/script.sh $ID with the parameter 
$ID containg the ID which got updated
 * generate and keep a checksum of the received data. Update and compare the 
checksum when new data is received
 * when the checksum is updated or some data times out, call the update-scipt

Shouldn't be so hard, and could still fit in the "lightweight" concept. ;) Are 
you willing to work on that?

BTW, I'm still waiting for your updated bat-hosts lua patch. :)

Cheers,
    Simon