feat: license, cronjob, requirements and packaging

.gitignore

@@ -1,3 +1,5 @@
 /.idea/
 /cfg/
 /venv/
+/build/
+**/*.egg-info/

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2023 Daniel Langbein <daniel@systemli.org>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

cron.d/netcup-dns

@@ -0,0 +1,11 @@
+# Run command every 3min
+# - https://crontab.guru/every-3-minutes
+# `/etc/cron.d/` requires user field
+# - https://unix.stackexchange.com/questions/458713/how-are-files-under-etc-cron-d-used#comment1019389_458715
+# Some users report that files in `/etc/cron.d/` containing `-` are not executed
+# - https://unix.stackexchange.com/questions/296347/crontab-never-running-while-in-etc-cron-d#comment640748_296351
+# PATH is restricted to `/bin:/usr/bin` but `de-p1st-execNotify` resides in `/usr/local/bin/`
+# - https://serverfault.com/a/449652
+
+PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin/
+*/3 * * * * root de-p1st-execNotify netcup-dns > /var/log/netcup-dns.cron 2>&1

pyproject.toml

@@ -0,0 +1,8 @@
+# https://packaging.python.org/tutorials/packaging-projects/#creating-pyproject-toml
+
+[build-system]
+requires = [
+    "setuptools>=42",
+    "wheel"
+]
+build-backend = "setuptools.build_meta"

requirements.txt

@@ -1 +1,2 @@
 nc-dnsapi
+requests

setup.cfg

@@ -0,0 +1,35 @@
+; setup.cfg is the configuration file for setuptools.
+; https://packaging.python.org/tutorials/packaging-projects/#configuring-metadata
+
+[metadata]
+name = netcup_dns
+version = 0.1.0
+author = Daniel Langbein
+author_email = daniel@systemli.org
+description = Update DNS records with your current external IP address using the netcup DNS API.
+long_description = file: README.md
+long_description_content_type = text/markdown
+url = https://codeberg.org/privacy1st/netcup-dns
+project_urls =
+    Bug Tracker = https://codeberg.org/privacy1st/netcup-dns/issues
+
+; https://pypi.org/classifiers/
+classifiers =
+    Development Status :: 4 - Beta
+    Programming Language :: Python :: 3
+    License :: OSI Approved :: MIT License
+    Operating System :: Unix
+
+[options]
+package_dir =
+    = src
+packages = find:
+python_requires = >=3.6.9
+
+[options.packages.find]
+where = src
+
+[options.entry_points]
+; https://setuptools.readthedocs.io/en/latest/userguide/entry_point.html
+console_scripts=
+    netcup-dns = netcup_dns.main:main

src/netcup_dns/main.py

@@ -1,5 +1,8 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
 import configparser
 import ipaddress
+from functools import lru_cache
 from pathlib import Path
 
 import requests
@@ -8,14 +11,16 @@ from nc_dnsapi import Client, DNSRecord
 
 def main():
     """
-    https://github.com/nbuchwitz/nc_dnsapi
+    The main effort is done by https://github.com/nbuchwitz/nc_dnsapi
     """
-    destination = external_ipv4()
+    cfg_dir = Path('cfg')
+    if not cfg_dir.exists():
+        raise Exception(f'The config directory is missing: {cfg_dir}')
 
-    files = [file for file in Path('cfg').iterdir() if file.name.endswith('.cfg') and file.is_file()]
+    cfg_files = [file for file in cfg_dir.iterdir() if file.name.endswith('.ini') and file.is_file()]
-    for file in files:
+    for cfg_file in cfg_files:
         cfg = configparser.ConfigParser()
-        cfg.read(file)
+        cfg.read(cfg_file)
         customer = cfg['credentials']['customer']
         api_key = cfg['credentials']['api_key']
         api_password = cfg['credentials']['api_password']
@@ -25,8 +30,13 @@ def main():
         with Client(customer, api_key, api_password) as api:
             for domain in domains:
                 hostname = cfg[domain]['hostname']
-                type_ = cfg[domain]['type']
+                type_ = cfg[domain]['type'].upper()
-                update_record_destination(api, domain, hostname, type_, destination)
+                if type_ == 'A':
+                    destination = external_ipv4()
+                    update_record_destination(api, domain, hostname, type_, destination=destination)
+                    print(f'Set {hostname}.{domain} {type_} record to {destination}')
+                else:
+                    raise Exception(f'DNS record type {type_} is not supported.')
 
 
 def update_record_destination(api: Client, domain: str, hostname: str, type_: str, destination: str) -> None:
@@ -45,8 +55,10 @@ def get_record(api: Client, domain: str, hostname: str, type_: str) -> DNSRecord
     return matches[0]
 
 
-def external_ipv4() -> str:
+@lru_cache(maxsize=None)
+def external_ipv4(timeout=5) -> str:
     """
+    :argument timeout: Timeout for each IP detection webservice in seconds.
     :return: Public IPv4 address
     """
 
@@ -67,7 +79,7 @@ def external_ipv4() -> str:
             requests.packages.urllib3.util.connection.HAS_IPV6 = False
 
             # Timeout after 5 seconds.
-            ip = requests.get(endpoint, timeout=5).text.strip()
+            ip = requests.get(endpoint, timeout=timeout).text.strip()
             # Check if it is actually an IPv4 address.
             # Some services, such as e.g. v4.ident.me, sometimes return IPv6.
             ipv4 = ipaddress.ip_address(ip)