does code have listenable external trigger for when a change of IP is detected

[dkebler]

I didn't see anything in the docs so I am asking.

1. does the code only attempt to update the record if the public ip returned is different than the current record?
2. Can one somehow "listen" for when the public IP has changed (or is there some trigger available).

My use case is that I run a site to site VPN tunnel and if the IP address of either end changes then the vpn must be restarted so that the a tunnel can be established to the new IP.

[dkebler]

I have written similar code in nodejs but that code is a few years old and it a hassle to deploy so hoping I can use your nice compiled GO project instead.

[dkebler]

now that I know that it will run as a one off I can build a bash script around it.
#1164

Still it would be great to pass some executable and have it run it on change.

[dkebler]

would be nice to have a usable return status. (failed, no change, change) Right now all I seem to be able to do is grep on "not changed" which is not robust if you change the wording of the log or if the program eventually supports a locale.

[dkebler]

so rather than a cron job I can run a systemd timer which will allow a bash script that calls ddns-route53.
https://www.baeldung.com/linux/systemd-service-periodic-restart

[dkebler]

#!/bin/bash
sdir="$(dirname -- "$( readlink -f -- "$0"; )")"
[[ ! $1 ]] && echo config yaml file required && exit 1
conf=$1.yml
if [[ ! -f $conf ]]; then 
  conf=$sdir/$conf
  [[ ! -f $conf ]] && echo unable to find configuration file $1 && exit 2
fi
cred=$1.env
if [[  ! -f $cred ]]; then
   cred=$sdir/$cred 
   if [[ ! -f $cred ]]; then
    cred=credentials.env
    if [[ ! -f $cred ]]; then
      cred=$sdir/$cred
      [[ ! -f $cred ]] &&  echo unable to find a credentials file && exit 3
    fi   
   fi
fi
    
echo running ddns-route53 using configuration file $conf and credentials file $cred
if result=$(source $cred; $sdir/ddns-route53 --config $conf); then
  if [[ "$(echo $result | grep "set updated")" ]]; then
    echo public ip changed.  Do something.
  else
    echo public ip not changed.  Nothing to do
  fi
  # echo $result
else
echo error trying to set ddns, $?
fi