cloudflare-ddns/cloudflare-ddns.py

import requests, json, sys, signal, os, time, threading

PATH = os.getcwd() + "/"
version = float(str(sys.version_info[0]) + "." + str(sys.version_info[1]))
shown_ipv4_warning = False
shown_ipv6_warning = False

if(version < 3.5):
    raise Exception("🐍 This script requires Python 3.5+")

class GracefulExit:
  def __init__(self):
    self.kill_now = threading.Event()
    signal.signal(signal.SIGINT, self.exit_gracefully)
    signal.signal(signal.SIGTERM, self.exit_gracefully)

  def exit_gracefully(self, signum, frame):
    print("🛑 Stopping main thread...")
    self.kill_now.set()

config = None
try:
    with open(PATH + "config.json") as config_file:
        config = json.loads(config_file.read())
except:
    print("😡 Error reading config.json")
    time.sleep(60) # wait 60 seconds to prevent excessive logging on docker auto restart

def deleteEntries(type):
    # Helper function for deleting A or AAAA records
    # in the case of no IPv4 or IPv6 connection, yet
    # existing A or AAAA records are found.
    for option in config["cloudflare"]:
        answer = cf_api(
            "zones/" + option['zone_id'] + "/dns_records?per_page=100&type=" + type,
            "GET", option)
        for record in answer["result"]:
            identifier = str(record["id"])
            cf_api(
                "zones/" + option['zone_id'] + "/dns_records/" + identifier, 
                "DELETE", option)
            print("🗑️ Deleted stale record " + identifier)

def getIPs():
    global shown_ipv4_warning
    global shown_ipv6_warning
    a = None
    aaaa = None
    try:
        a = requests.get("https://1.1.1.1/cdn-cgi/trace").text.split("\n")
        a.pop()
        a = dict(s.split("=") for s in a)["ip"]
    except Exception:
        if not shown_ipv4_warning:
            shown_ipv4_warning = True
            print("🧩 IPv4 not detected")
        deleteEntries("A")
    try:
        aaaa = requests.get("https://[2606:4700:4700::1111]/cdn-cgi/trace").text.split("\n")
        aaaa.pop()
        aaaa = dict(s.split("=") for s in aaaa)["ip"]
    except Exception:
        if not shown_ipv6_warning:
            shown_ipv6_warning = True
            print("🧩 IPv6 not detected")
        deleteEntries("AAAA")
    ips = {}
    if(a is not None):
        ips["ipv4"] = {
            "type": "A",
            "ip": a
        }
    if(aaaa is not None):
        ips["ipv6"] = {
            "type": "AAAA",
            "ip": aaaa
        }
    return ips

def commitRecord(ip):
    for option in config["cloudflare"]:
        subdomains = option["subdomains"]
        response = cf_api("zones/" + option['zone_id'], "GET", option)
        base_domain_name = response["result"]["name"]
        ttl = 300 # default Cloudflare TTL
        for subdomain in subdomains:
            subdomain = subdomain.lower().strip()
            record = {
                "type": ip["type"],
                "name": subdomain,
                "content": ip["ip"],
                "proxied": option["proxied"],
                "ttl": ttl
            }
            dns_records = cf_api(
                "zones/" + option['zone_id'] + "/dns_records?per_page=100&type=" + ip["type"], 
                "GET", option)
            fqdn = base_domain_name
            if subdomain:
                fqdn = subdomain + "." + base_domain_name
            identifier = None
            modified = False
            duplicate_ids = []
            if dns_records is not None:
                for r in dns_records["result"]:
                    if (r["name"] == fqdn):
                        if identifier:
                            if r["content"] == ip["ip"]:
                                duplicate_ids.append(identifier)
                                identifier = r["id"]
                            else:
                                duplicate_ids.append(r["id"])
                        else:
                            identifier = r["id"]
                            if r['content'] != record['content'] or r['proxied'] != record['proxied']:
                                modified = True
            if identifier:
                if modified:
                    print("📡 Updating record " + str(record))
                    response = cf_api(
                        "zones/" + option['zone_id'] + "/dns_records/" + identifier,
                        "PUT", option, {}, record)
            else:
                print("➕ Adding new record " + str(record))
                response = cf_api(
                    "zones/" + option['zone_id'] + "/dns_records", "POST", option, {}, record)
            for identifier in duplicate_ids:
                identifier = str(identifier)
                print("🗑️ Deleting stale record " + identifier)
                response = cf_api(
                    "zones/" + option['zone_id'] + "/dns_records/" + identifier,
                    "DELETE", option)
    return True

def cf_api(endpoint, method, config, headers={}, data=False):
    api_token = config['authentication']['api_token']
    if api_token != '' and api_token != 'api_token_here':
        headers = {
            "Authorization": "Bearer " + api_token,
            **headers
        }
    else:
        headers = {
            "X-Auth-Email": config['authentication']['api_key']['account_email'],
            "X-Auth-Key": config['authentication']['api_key']['api_key'],
        }

    if(data == False):
        response = requests.request(
            method, "https://api.cloudflare.com/client/v4/" + endpoint, headers=headers)
    else:
        response = requests.request(
            method, "https://api.cloudflare.com/client/v4/" + endpoint,
            headers=headers, json=data)

    if response.ok:
        return response.json()
    else:
        print("📈 Rate limit exceeded")
        return None

def updateIPs(ips):
    for ip in ips.values():
        commitRecord(ip)

if __name__ == '__main__' and config is not None:
    if(len(sys.argv) > 1):
        if(sys.argv[1] == "--repeat"):
            delay = 60
            print("🕰️ Updating IPv4 (A) & IPv6 (AAAA) records every minute")
            next_time = time.time()
            killer = GracefulExit()
            prev_ips = None
            while True:
                if killer.kill_now.wait(delay):
                    break
                updateIPs(getIPs())
        else:
            print("❓ Unrecognized parameter '" + sys.argv[1] + "'. Stopping now.")
    else:
        updateIPs(getIPs())