DNS Monitoring Script for Go-Live Moments

monitor-dns-during-go-live.sh

#!/bin/bash

# Replace these with your Pushover credentials
APP_TOKEN="your_app_token"
USER_KEY="your_user_key"

# Expected IP addresses
EXPECTED_IP_A="your_expected_ipv64_address"
EXPECTED_IP_AAAA="your_expected_ipv6_address"

# Domain to monitor
DOMAIN="your-domain.com"

# Log file path
LOG_FILE="dns_monitor.log"

# List of DNS servers to monitor
DNS_SERVERS=(
  "dns1.your-domain.com"
  "dns2.your-domain.com"
)

while true; do
  TIMESTAMP=$(date "+%Y-%m-%d %H:%M:%S")

  for DNS_SERVER in "${DNS_SERVERS[@]}"; do
    # Check A record
    IP_A=$(dig @$DNS_SERVER $DOMAIN A +short)
    if [ "$IP_A" != "$EXPECTED_IP_A" ]; then
      # Sound alarm and send Pushover notification
      say "Changed"
      curl -s \
        --form-string "token=$APP_TOKEN" \
        --form-string "user=$USER_KEY" \
        --form-string "message=A record at $DNS_SERVER for $DOMAIN changed to $IP_A" \
        https://api.pushover.net/1/messages.json
      echo "$TIMESTAMP - A record at $DNS_SERVER for $DOMAIN changed to $IP_A" | tee -a "$LOG_FILE"
    else
      echo "$TIMESTAMP - no change for A record at $DNS_SERVER for $DOMAIN" | tee -a "$LOG_FILE"
    fi

    # Check AAAA record
    IP_AAAA=$(dig @$DNS_SERVER $DOMAIN AAAA +short)
    if [ -n "$IP_AAAA" ] && [ "$IP_AAAA" != "$EXPECTED_IP_AAAA" ]; then
      # Sound alarm and send Pushover notification
      say "Changed"
      curl -s \
        --form-string "token=$APP_TOKEN" \
        --form-string "user=$USER_KEY" \
        --form-string "message=AAAA record at $DNS_SERVER for $DOMAIN changed to $IP_AAAA" \
        https://api.pushover.net/1/messages.json
      echo "$TIMESTAMP - AAAA record at $DNS_SERVER for $DOMAIN changed to $IP_AAAA" | tee -a "$LOG_FILE"
    else
      echo "$TIMESTAMP - no change for AAAA record at $DNS_SERVER for $DOMAIN" | tee -a "$LOG_FILE"
    fi
  done

  sleep 2
done