May 26, 2012
Notify me if IP is propagated in DNS
Posted by: gdelmatto : Category: Memos
So here’s my short snipped of a bash shell loop I hacked up.
It’s only purpose is to check in DNS repeatedly if a certain IP address is propagated for a given fully qualified domain name.
If the script sees the IP address, it would “ring the bell” and exit, otherwise it sleeps for a while and repeats the check.
This way I could leave it running in the console and – whenever the IP appeared in DNS – I’d get an audible alert.
No big trick after all 😉
Here’s the code:
$ while [ : ] ; do echo scanning ... ; dig @DNSSERVER FQDN | grep IPADDR && { echo -e "\a"; break; } || sleep 5; done
And here’s what it looks like in action:
scanning ... scanning ... scanning ... scanning ... scanning ... scanning ... my-cool-fqdn.some.domain.tld. 3600 IN A 192.0.2.1 [you would hear a "bing" tone at this point as well]
