#!/bin/bash

# Author: Besmir Zanaj, 2024
# This is a very raw script to backup configs (no logs and no stats) from a technitium server 
# to another
#
## 20250814 Stocker Modify to Set DHCP Delay Time to 2000MS rather than disable DHCP Scope
## 20250815 Stocker modify DNS Server Internal IP bind
###########################################################################################
# first create two tokens: one on the source server and another one on the destination one
# fill out the vars below
# create a cronjob with this script on the destinaton host
# eg:
# 30 */6 * * * /path-to/technitium-sync.sh

set -euxo pipefail

src_dns_server='source.ip.address'
dst_dns_server='dest.ip.address'
src_dns_serverdomain='fqdn.of.source.server'
dst_dns_serverdomain='fqdn.of.dest.server'
src_dns_token='SOURCE_TECHNITIUM_TOKEN_HERE'
dst_dns_token='DEST_TECHNITIUM_TOKEN_HERE'
backup_file="/tmp/technitium-backup.zip"
# update the dhcp scope as per your local settings
dhcp_scope_name="local-home"

# Ensure required tools are installed
command -v curl >/dev/null 2>&1 || { echo "curl is not installed. Aborting." >&2; exit 1; }

# Check the primary server's health before running the script
echo "Checking primary Technitium server status"
status_code=$(curl --write-out %{http_code} --silent --output /dev/null http://$src_dns_server:5380)

if [[ "$status_code" -ne 200 ]] ; then
  echo "Primary DNS server is not available. Skipping backup"
  exit 1
else
  echo "Getting the backup archive from the primary server"
  curl -s "http://$src_dns_server:5380/api/settings/backup?token=$src_dns_token&blockLists=true&logs=false&scopes=true&stats=false&zones=true&allowedZones=true&blockedZones=true&dnsSettings=true&logSettings=true&authConfig=true&apps=true" -o $backup_file
fi

# restore_backup
if [[ -f "$backup_file" ]]; then
  echo "Restoring the backup on $HOSTNAME"
  curl -s --form file="@$backup_file" "http://$dst_dns_server:5380/api/settings/restore?token=$dst_dns_token&blockLists=true&logs=true&scopes=true&stats=true&apps=true&zones=true&allowedZones=true&blockedZones=true&dnsSettings=true&logSettings=true&deleteExistingFiles=true&authConfig=true"  --output /dev/null

  # wait for server to come back
  echo "Waiting for 10 seconds for the destination server to start up"
  sleep 10

  # set dnsServerDomain on destination server
  echo "Updating DNS server Domain and IP in destination server"
  #curl -k -X POST "https://$dst_dns_server:53443/api/settings/set?token=$dst_dns_token&dnsServerDomain=$dst_dns_serverdomain&dnsServerLocalEndPoints=dst_dns_server
  curl -k -X POST "https://$dst_dns_server:53443/api/settings/set?token=$dst_dns_token&dnsServerDomain=$dst_dns_serverdomain&dnsServerLocalEndPoints=$dst_dns_server"



  # disable DHCP on the destination server
  #echo "disabling DHCP in destination server"
  #curl -X POST "http://$dst_dns_server:5380/api/dhcp/scopes/disable?token=$dst_dns_token&name=$dhcp_scope_name"
  # Set DHCP Response to really high on backup
  echo "Updating DHCP Offer Delay"
  curl -X POST "http://$dst_dns_server:5380/api/dhcp/scopes/set?token=$dst_dns_token&name=$dhcp_scope_name&offerDelayTime=2000"

  # cleanup
  echo "Cleaning up temporary files"
  rm -rf $backup_file
fi