Zabbix template bash generator

#!/bin/bash
set -eu

create_item(){
  dnshost=$1
  fqdn=$2
  uuidv4=$(uuid -v 4 | sed 's/-//g')
  item_line=$(cat <<EOF
        -
          uuid: ${uuidv4}
          name: ${dnshost}_${fqdn}
          type: EXTERNAL
          key: 'dnsname-resolve["${dnshost}", "${fqdn}"]'
EOF
  )

  echo "${item_line}"
}



create_header(){
  header_line=$(cat <<EOF
zabbix_export:
  version: '6.0'
  date: '2023-02-10T18:59:20Z'
  groups:
    -
      uuid: 3f372bbb7eca47978fc251a6312cc577
      name: Green
  templates:
    -
      uuid: 840d80e8fc84470ba450e5bddb82a736
      template: dns-resolver-tests
      name: dns-resolver-tests
      groups:
        -
          name: Green
      items:
EOF
  )
  echo "${header_line}"
}


main(){
  create_header
  for dnshost in $(cat dnshosts.txt); do
    for fqdn in $(cat fqdns.txt); do
      create_item ${dnshost} ${fqdn}
    done
  done
}

main