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Add tracker record support and update configuration options

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This commit is contained in:
Nik Rozman
2026-03-27 19:31:08 +01:00
parent 5408add86b
commit 1824ae70a1
3 changed files with 119 additions and 8 deletions
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116
cloudflare_dyndns.py
View File

@@ -10,11 +10,17 @@ Config (config.ini by default):
zone_id = <zone id>
[service]
ipinfo_url = https://ipinfo.io/ip ; optional
poll_seconds = 3600 ; optional
ipinfo_url = https://ipinfo.io/ip ; optional
poll_seconds = 3600 ; optional
tracker_record = _dyndns-last-ip ; TXT record name used as source of truth
; for the last IP this app set; create it
; manually in Cloudflare with the current A
; record IP before first run so the app knows
; what to look for.
Environment overrides (take precedence over config file):
CLOUDFLARE_API_TOKEN, CLOUDFLARE_ZONE_ID, IPINFO_URL, POLL_SECONDS, CONFIG_PATH, LAST_IP_OVERRIDE
CLOUDFLARE_API_TOKEN, CLOUDFLARE_ZONE_ID, IPINFO_URL, POLL_SECONDS, CONFIG_PATH,
LAST_IP_OVERRIDE, LAST_IP_FILE, TRACKER_RECORD
"""
from __future__ import annotations
@@ -35,6 +41,7 @@ IP_SOURCES = [
"https://icanhazip.com",
]
DEFAULT_POLL_SECONDS = 3600
DEFAULT_LAST_IP_FILE = "last_ip.txt"
# Minimum agreeing sources needed to trust an IP result.
MIN_AGREEING_SOURCES = 2
@@ -47,6 +54,22 @@ def is_valid_ipv4(ip: str) -> bool:
return all(0 <= int(part) <= 255 for part in ip.split("."))
def read_last_ip_file(path: str) -> Optional[str]:
try:
ip = open(path).read().strip()
return ip if is_valid_ipv4(ip) else None
except FileNotFoundError:
return None
def write_last_ip_file(path: str, ip: str) -> None:
try:
with open(path, "w") as f:
f.write(ip)
except OSError as exc:
print(f"Warning: could not write last IP file {path!r}: {exc}", file=sys.stderr)
def load_config(path: str) -> dict:
parser = configparser.ConfigParser()
if not os.path.exists(path):
@@ -66,6 +89,7 @@ def load_config(path: str) -> dict:
"ipinfo_url": get_opt("service", "ipinfo_url"),
"poll_seconds": None,
"last_ip_override": get_opt("service", "last_ip_override"),
"tracker_record": get_opt("service", "tracker_record"),
}
poll_raw = get_opt("service", "poll_seconds")
@@ -142,6 +166,52 @@ def fetch_records_with_ip(
return records
def fetch_tracker_record(
session: requests.Session,
token: str,
zone_id: str,
name: str,
) -> tuple[Optional[str], Optional[str]]:
"""Return (record_id, ip_value) from the TXT tracker record, or (None, None)."""
headers = {"Authorization": f"Bearer {token}", "Content-Type": "application/json"}
url = f"https://api.cloudflare.com/client/v4/zones/{zone_id}/dns_records"
resp = session.get(url, headers=headers, params={"type": "TXT", "name": name}, timeout=15)
resp.raise_for_status()
data = resp.json()
if not data.get("success"):
raise RuntimeError(f"Cloudflare API error fetching tracker record: {data}")
results = data.get("result", [])
if not results:
return None, None
rec = results[0]
# TXT content is wrapped in quotes by Cloudflare.
ip = rec["content"].strip('"').strip()
return rec["id"], ip if is_valid_ipv4(ip) else None
def upsert_tracker_record(
session: requests.Session,
token: str,
zone_id: str,
name: str,
ip: str,
record_id: Optional[str],
) -> None:
"""Create or update the TXT tracker record with the given IP."""
headers = {"Authorization": f"Bearer {token}", "Content-Type": "application/json"}
payload = {"type": "TXT", "name": name, "content": ip, "ttl": 60}
if record_id:
url = f"https://api.cloudflare.com/client/v4/zones/{zone_id}/dns_records/{record_id}"
resp = session.put(url, headers=headers, json=payload, timeout=15)
else:
url = f"https://api.cloudflare.com/client/v4/zones/{zone_id}/dns_records"
resp = session.post(url, headers=headers, json=payload, timeout=15)
resp.raise_for_status()
data = resp.json()
if not data.get("success"):
raise RuntimeError(f"Failed to upsert tracker record {name!r}: {data}")
def update_record_ip(
session: requests.Session,
token: str,
@@ -186,14 +256,35 @@ def main() -> None:
poll_seconds = config.get("poll_seconds") or DEFAULT_POLL_SECONDS
last_ip_override = os.getenv("LAST_IP_OVERRIDE") or config.get("last_ip_override")
last_ip_file = os.getenv("LAST_IP_FILE", DEFAULT_LAST_IP_FILE)
tracker_record = os.getenv("TRACKER_RECORD") or config.get("tracker_record")
session = requests.Session()
last_ip: Optional[str] = last_ip_override
# Determine starting last_ip:
# explicit override > Cloudflare TXT tracker > persisted file > None
tracker_record_id: Optional[str] = None
if last_ip_override:
last_ip: Optional[str] = last_ip_override
elif tracker_record:
try:
tracker_record_id, last_ip = fetch_tracker_record(session, token, zone_id, tracker_record)
except Exception as exc:
print(f"Warning: could not read tracker record {tracker_record!r}: {exc}", file=sys.stderr)
last_ip = read_last_ip_file(last_ip_file)
else:
last_ip = read_last_ip_file(last_ip_file)
print(f"Starting Cloudflare DDNS watcher (interval={poll_seconds}s)")
print(f"Primary IP endpoint: {ipinfo_url} (with {len(IP_SOURCES) - 1} fallbacks)")
if tracker_record:
print(f"Tracker TXT record: {tracker_record} (id={tracker_record_id or 'not found — will create'})")
else:
print(f"Last IP file: {last_ip_file}")
if last_ip_override:
print(f"Starting with overridden last_ip: {last_ip_override}")
elif last_ip:
print(f"Resuming with last_ip: {last_ip}")
try:
while True:
@@ -206,7 +297,16 @@ def main() -> None:
if last_ip is None:
last_ip = current_ip
print(f"Initial IP: {current_ip}")
write_last_ip_file(last_ip_file, last_ip)
if tracker_record:
try:
upsert_tracker_record(session, token, zone_id, tracker_record, last_ip, tracker_record_id)
print(f"Initial IP: {current_ip} (tracker record set)")
except Exception as exc:
print(f"Warning: could not set tracker record: {exc}", file=sys.stderr)
print(f"Initial IP: {current_ip}")
else:
print(f"Initial IP: {current_ip}")
elif current_ip != last_ip:
print(f"IP changed: {last_ip} -> {current_ip}")
try:
@@ -223,6 +323,12 @@ def main() -> None:
# Advance last_ip regardless — old IP is gone, no point
# searching for it again next cycle.
last_ip = current_ip
write_last_ip_file(last_ip_file, last_ip)
if tracker_record:
try:
upsert_tracker_record(session, token, zone_id, tracker_record, last_ip, tracker_record_id)
except Exception as exc:
print(f"Warning: could not update tracker record: {exc}", file=sys.stderr)
except Exception as api_err:
print(f"Cloudflare update failed: {api_err}", file=sys.stderr)
# Do NOT advance last_ip; retry on next cycle.

9
config.example.ini
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@@ -5,5 +5,12 @@ zone_id = YOUR_ZONE_ID
[service]
ipinfo_url = https://ipinfo.io/ip
poll_seconds = 3600
; Optionally seed last_ip to force an update on first run
; TXT record used as source of truth for the last IP this app set.
; Create it manually in Cloudflare with your current A record IP before
; first run (Name: _dyndns-last-ip, Type: TXT, Content: x.x.x.x, TTL: 60).
; The app will update it automatically on each IP change.
tracker_record = _dyndns-last-ip
; Optionally force a specific starting IP (overrides tracker record and last_ip.txt)
; last_ip_override = 203.0.113.10

2
docker-compose.yml
View File

@@ -1,5 +1,3 @@
version: "3.9"
services:
cloudflare-dyndns:
image: python:3.11-slim