add update-zone-serial tool

scripts/generate-roa.sh

@@ -22,4 +22,6 @@ scripts/roa.py -m "$MAX_LEN_4" -M "$MAX_LEN_6" -e -o generated/neonetwork.json
 scripts/roa.py -m "$MAX_LEN_4" -M "$MAX_LEN_6" -r -o generated/rfc8416.json
 scripts/roa.py --summary --output generated/README.md
 
+scripts/update-zone-serial.py
+
 scripts/check-named-zones.sh

scripts/update-zone-serial.py

@@ -0,0 +1,41 @@
+#!/usr/bin/env python3
+from pathlib import Path
+import subprocess
+from time import time
+from re import match
+from os import chdir
+
+chdir("generated")
+
+zone_files = [
+    'neonetwork',
+    'db.10.127',
+    'db.fd10.127',
+]
+
+serial_base = 1586876035
+
+for zone in zone_files:
+    zone = Path("dns") / zone
+    assert zone.exists()
+    p = subprocess.run(['git', 'diff', '--exit-code', str(zone)])
+    if p.returncode == 0:
+        print(f"skip {zone.name}")
+    else:
+        print(f"update serial {zone.name}")
+        lines = zone.read_text().split("\n")
+        processed = list()
+        serial = int(time()) - serial_base
+        assert 0 < serial <= 2**32
+        serial = str(serial)
+        found = False
+        for line in lines:
+            if not found and (m := match(r"^(\s+)([0-9]+)(\s*;\s*Serial\s*)$", line)):
+                prefix, _serial, suffix = m.groups()
+                print(f"{_serial=} {serial=}")
+                plen = max(len(prefix) - len(serial) + len(_serial), 0)
+                processed.append(f"{' '*plen}{serial}{suffix}")
+                found = True
+            else:
+                processed.append(line)
+        zone.write_text("\n".join(processed))