Move disclaimer to the bottom of README.md

README.md

@@ -10,9 +10,6 @@ By leveraging the DHCPv4 lease information and mapping it to the MAC address, th
 
 Define the environment variables in the docker-compose file, then run: `docker compose up -d`
 
-#### Disclaimer:
-If DNS records are not being added, make sure that the corresponding reverse zone exists in Technitium DNS, otherwise the script will fail silently.
-
 ### Environment variables:
 
 | Variable Name         | Description                                                                              | Example Value                                                          |
@@ -30,6 +27,7 @@ If DNS records are not being added, make sure that the corresponding reverse zon
 
 ### Note
 You have to create the corresponding DNS zones in the Technitium dashboard, you can configure them as primary or conditional forwarder zones.
+If DNS records are not being added, make sure that the corresponding reverse zone exists in Technitium DNS, otherwise the script will fail silently.
 
 ### Contributing:
 I welcome contributions! Feel free to submit issues, feature requests, or pull requests.

cleanup.py

@@ -0,0 +1,63 @@
+import os
+import logging
+import requests
+import urllib3
+import ipaddress
+
+# Environment variables
+TECHNITIUM_URL = os.getenv("TECHNITIUM_URL", None)
+TECHNITIUM_TOKEN = os.getenv("TECHNITIUM_TOKEN", None)
+VERIFY_HTTPS = (os.getenv("VERIFY_HTTPS", "true").lower() == "true")
+DNS_ZONE_SUBNETS = os.getenv("DNS_ZONE_SUBNETS", None)
+
+def get_existing_records(domain, zone):
+    url = f"{TECHNITIUM_URL}/api/zones/records/get?token={TECHNITIUM_TOKEN}&domain={domain}.{zone}"
+    r = requests.get(url=url, verify=VERIFY_HTTPS)
+    if r.status_code != 200:
+        logging.error(f"Error fetching records for {domain}.{zone}: {r.status_code} - {r.text}")
+        return []
+    return r.json().get("response", {}).get("records", [])
+
+def delete_record(zone, domain, record_type, value):
+    url = f"{TECHNITIUM_URL}/api/zones/records/delete?token={TECHNITIUM_TOKEN}&domain={domain}.{zone}&zone={zone}&type={record_type}&value={value}"
+    r = requests.get(url=url, verify=VERIFY_HTTPS)
+    if r.status_code != 200:
+        logging.error(f"Error deleting {record_type} record {value} in {domain}.{zone}: {r.status_code} - {r.text}")
+    else:
+        logging.info(f"Deleted {record_type} record {value} in {domain}.{zone}")
+
+def cleanup_zone(zone, subnet):
+    logging.info(f"Cleaning up zone: {zone} for subnet: {subnet}")
+    ip_network = ipaddress.ip_network(subnet)
+
+    # Loop through all possible addresses in the subnet
+    for ip in ip_network:
+        domain = str(ip.reverse_pointer)[2:]  # PTR-like domain
+        existing_records = get_existing_records(domain, zone)
+
+        # Delete all A/AAAA records for the domain
+        for record in existing_records:
+            record_type = record["type"]
+            if record_type in ["A", "AAAA"]:
+                delete_record(zone, domain, record_type, record["rData"]["ipAddress"])
+
+def run_cleanup():
+    if not VERIFY_HTTPS:
+        urllib3.disable_warnings()
+
+    if not TECHNITIUM_URL or not TECHNITIUM_TOKEN or not DNS_ZONE_SUBNETS:
+        logging.error("Missing mandatory environment variables.")
+        exit(1)
+
+    zones = []
+    for z in DNS_ZONE_SUBNETS.split(","):
+        subnet, zone = z.split("=")
+        zones.append((subnet, zone))
+
+    for subnet, zone in zones:
+        cleanup_zone(zone, subnet)
+
+if __name__ == "__main__":
+    logging.basicConfig(level=logging.INFO)
+    logging.info("Starting DNS cleanup script...")
+    run_cleanup()