A little bit of bash goes a long way...

So I need to find the current (dynamic) IP of a domain.
From inside a container that I don't own (I just operate).

I have to lookup SRV records first to be "technically correct".
dig is not installed.

But...nslookup! And a few others...

So... behold!

DOMAIN=$(nslookup -type=SRV _stun._tcp.example.com | grep _stun._tcp.example.com | cut -f6 -d ' '); nslookup $DOMAIN | grep "Address:" | tail -n 1 | cut -f2 -d ' '

Brittle as fuck probably, but it works, and it took me about about 3min.

No slop involved fwiw, just some light net searching and vague memories...

No ofcourse the real troubles being - doing that on a schedule, and actually USING the result.

#selfhosting #bash #shell #script