Add Dynamic DNS records to UFW

ufw-dyndns.sh

#!/bin/bash
HOSTNAME="$1"

LOGDIR="$HOME/.ufw";
LOGFILE=$LOGDIR/$HOSTNAME
if [ ! -d "$LOGDIR" ];then
  mkdir $LOGDIR
fi

function _alert {
  echo "[$HOSTNAME] OLD:$OIP NEW:$CIP $1";
  ufw status | grep $CIP
  exit 0;
}

#### MAIN-FUNC #####

CIP=$(dig +short +nocomments $HOSTNAME | tail -1)

ISBLOCK="$(ufw status | grep "REJECT" | grep $CIP)"


if [ ! -f $LOGFILE ]; then
  /usr/sbin/ufw insert 1 allow from $CIP
  echo -n $CIP > $LOGFILE
else
  OIP=$(cat $LOGFILE)
  if [ "$ISBLOCK" ];then
     echo "$CIP is Blocked. Allowing now..."
     /usr/sbin/ufw delete reject from $CIP
     /usr/sbin/ufw insert 1 allow from $CIP

  elif [ "$CIP" = "$OIP" ] ; then
    _alert "no change."
  else
    /usr/sbin/ufw delete allow from $OIP
    /usr/sbin/ufw insert 1 allow from $CIP
    echo -n $CIP > $LOGFILE
    _alert "updated."
  fi
fi