checks if NS in zone and GLUE record are identical

check_glue.sh

#!/bin/bash

OK=0
WARNING=1
CRITICAL=2
UNKNOWN=3

domain=$1

if [[ -z "$domain" ]]
then
  echo "Usage: $0 <example.tld>"
  exit UNKNOWN
fi

contains() {
  [[ $1 =~ $2 ]]
}

ns_records="$(dig ns $domain +short)"
glue_records="$(dig +noall +authority ns $domain @$(dig ns $(echo $domain | cut -d '.' -f2). +short | shuf -n1) | awk '{print $5}')"

for ns in $ns_records
do
  if ! contains "$glue_records" "$ns" 
  then
  echo "WARNING - $ns not in glue records."
  exit WARNING
  fi
done;

for glue in $glue_records
do
  if ! contains "$ns_records" "$glue" 
  then
  echo "WARNING - $glue is missing in zone."
  exit WARNING
  fi
done;

echo "OK - Glue und NS are up to date."
exit OK