From 4d9138b8283eced0c5b47865e2023c63a55558c2 Mon Sep 17 00:00:00 2001
From: Christian Pointner <equinox@spreadspace.org>
Date: Fri, 11 Nov 2022 22:34:56 +0100
Subject: ch-pan: deploy new and improved dyndns/server

---
 roles/dyndns/server/templates/dyndns-regen.py.j2 | 109 +++++++++++++++++++++++
 1 file changed, 109 insertions(+)
 create mode 100644 roles/dyndns/server/templates/dyndns-regen.py.j2

(limited to 'roles/dyndns/server/templates/dyndns-regen.py.j2')

diff --git a/roles/dyndns/server/templates/dyndns-regen.py.j2 b/roles/dyndns/server/templates/dyndns-regen.py.j2
new file mode 100644
index 00000000..3611618d
--- /dev/null
+++ b/roles/dyndns/server/templates/dyndns-regen.py.j2
@@ -0,0 +1,109 @@
+#!/usr/bin/env python3
+#
+# dyndns.py
+#
+# a simple ssh based dyndns updater for bind zone files
+#
+# Copyright (C) 2013 Christian Pointner <equinox@spreadspace.org>
+#
+# This file is part of dyndns.py.
+#
+# dyndns.py is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 2 of the License, or
+# any later version.
+#
+# dyndns.py is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with dyndns.py. If not, see <http://www.gnu.org/licenses/>.
+#
+
+import subprocess
+import fcntl
+import shutil
+import hashlib
+import tempfile
+import sys
+import os
+
+if len(sys.argv) != 2:
+    print("ERROR: the base-domain-name must be the sole parameter")
+    sys.exit(1)
+
+
+domain = sys.argv[1]
+base_d = '/var/lib/dyndns'
+rndc = '/usr/sbin/rndc'
+
+digest_fn = os.path.join(base_d, 'digest.'+domain)
+header_fn = os.path.join(base_d, 'header.'+domain)
+records_fn = os.path.join(base_d, 'records.'+domain)
+tmpl_fn = os.path.join(base_d, 'tmpl.'+domain)
+serial_fn = os.path.join(base_d, 'serial.'+domain)
+db_fn = os.path.join(base_d, 'db.'+domain)
+
+digest_fd = open(digest_fn, 'a+')
+fcntl.flock(digest_fd, fcntl.LOCK_EX)
+digest_fd.seek(0)
+
+h = hashlib.blake2b()
+with open(tmpl_fn, 'wb+') as tmpl_fd:
+    with open(header_fn, 'rb') as header_fd:
+        shutil.copyfileobj(header_fd, tmpl_fd)
+    try:
+        with open(records_fn, 'rb') as records_fd:
+            shutil.copyfileobj(records_fd, tmpl_fd)
+    except FileNotFoundError:
+        pass
+
+    tmpl_fd.seek(0)
+    while True:
+        data = tmpl_fd.read(64*1024)
+        if not data:
+            break
+        h.update(data)
+
+old_digest = digest_fd.readline().strip()
+new_digest = h.hexdigest()
+if old_digest == new_digest:
+    print("OK: already up to date.")
+    sys.exit(0)
+
+serial = 0
+with open(serial_fn, 'a+') as serial_fd:
+    serial_fd.seek(0)
+    serial = int(serial_fd.readline()) + 1
+    serial_fd.truncate(0)
+    serial_fd.write(str(serial)+'\n')
+
+with tempfile.NamedTemporaryFile(dir=base_d, delete=False, mode='w') as out_fd:
+    with open(tmpl_fn, 'r') as tmpl_fd:
+        while True:
+            line = tmpl_fd.readline()
+            if not line:
+                break
+            line = line.replace('__SERIAL__', str(serial))
+            out_fd.write(line)
+    os.chmod(out_fd.name, 0o644)
+    os.rename(out_fd.name, db_fn)
+
+
+cmd = [rndc, 'reload', domain]
+p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
+rndc_output = ''
+for line in p.stdout.readlines():
+    rndc_output = rndc_output + line.decode('utf-8')
+
+r = p.wait()
+if r != 0:
+    print("ERROR: rndc returned %d\n\n%s" % (r, rndc_output))
+    sys.exit(1)
+
+digest_fd.truncate(0)
+digest_fd.write(new_digest + '\n')
+
+print("OK: " + rndc_output)
-- 
cgit v1.2.3