iankelling.org Git - distro-setup/blob - dynamic-ip-update.sh

   1 #!/bin/bash
   2
   3 set -eE -o pipefail
   4 trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
   5
   6
   7 cur="$(host -4 iank.pw iankelling.org | sed -rn 's/.*has address (.*)/\1/p;T;q')"
   8 ip=$(curl -s4 https://iankelling.org/cgi/pubip)
   9
  10 # note, a simpler way to do this would be to ssh and use
  11 # "${SSH_CLIENT%% *}
  12 # to update bind if needed.
  13
  14 if [[ $cur != $ip ]]; then
  15     nsupdate -k /p/c/machine_specific/li/filesystem/etc/bind/Kiank.pw.*.private <<EOF
  16 server iankelling.org
  17 zone iank.pw
  18 update delete iank.pw. A
  19 update add iank.pw. 300 A $ip
  20 update delete *.iank.pw. A
  21 update add *.iank.pw. 300 A $ip
  22 show
  23 send
  24 EOF
  25 fi
  26
  27 # persistent initial setup for this:
  28 # mkc /p/c/machine_specific/li/filesystem/etc/bind
  29 # s dnssec-keygen -a HMAC-MD5 -b 512 -n HOST iank.pw
  30 # s chown ian:ian *
  31
  32 # f=key.iank.pw
  33 # cat >$f <<EOF
  34 # key iank.pw. {
  35 # algorithm HMAC-MD5;
  36 # secret "$(awk '$1 == "Key:" {print $2}' Kiank.pw.*.private)";
  37 # };
  38 # EOF
  39 # chmod 640 $f