modified: catalog_zone_manager.py

modified:   management/commands/dns-export-zone.py
modified:   management/commands/dns-export-zones.py
modified:   management/commands/dns-transfer-endpoint.py
modified:   notify_handler.py
modified:   request_handler.py
Guard all db requests against broken database connections.
This commit is contained in:
Sven Luethi committed 2026-07-10 17:10:19 +02:00
1 parent d18e0fc262
commit 5747b044b6
6 files changed
+178 -148

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+116 -76
View File
@@ -7,7 +7,7 @@ from netbox_dns.models import Zone
from netbox_dns_bridge.models import IntegerKeyValueSetting, CatalogZoneMemberIdentifier
from uuid import uuid4
from base64 import b32encode
from django.db import transaction
from django.db import transaction, close_old_connections, OperationalError
logger = get_logger(__name__)
@@ -17,19 +17,9 @@ def init() -> None:
_create_missing_member_identifiers()
def _init_soa_serial() -> None:
try:
IntegerKeyValueSetting.objects.get(key="catalog-zone-soa-serial")
logger.info("Catalog zone SOA serial number loaded from database")
except IntegerKeyValueSetting.DoesNotExist:
IntegerKeyValueSetting.objects.create(key="catalog-zone-soa-serial", value=1)
logger.debug(
"Catalog zone SOA serial number was not set in the database. Set to 1"
)
def increment_soa_serial() -> int:
with transaction.atomic():
try:
soa_serial = IntegerKeyValueSetting.objects.select_for_update().get(
key="catalog-zone-soa-serial"
)
@@ -46,37 +36,14 @@ def increment_soa_serial() -> int:
logger.debug(f"Catalog zone SOA serial number is now {soa_serial.value}")
return soa_serial.value
def _create_missing_member_identifiers() -> None:
existing_zone_ids = CatalogZoneMemberIdentifier.objects.values_list(
"zone_id", flat=True
)
missing_zones = Zone.objects.exclude(id__in=existing_zone_ids)
new_objects = [
CatalogZoneMemberIdentifier(
zone=zone,
name=_generate_member_identifier(),
)
for zone in missing_zones
]
for identifier in new_objects:
logger.debug(
f"Zone {identifier.zone} missing catz member identifier. Creating..."
)
CatalogZoneMemberIdentifier.objects.bulk_create(
new_objects,
ignore_conflicts=False,
except OperationalError as e:
logger.error(
f"ERROR: Unable to increment the Catalog Zone's SOA serial: {e}"
)
close_old_connections()
def create_zone(name, view_name) -> dns.zone.Zone:
soa_serial = IntegerKeyValueSetting.objects.get(key="catalog-zone-soa-serial").value
# Zone origin
origin = dns.name.from_text(name, dns.name.root)
@@ -84,6 +51,7 @@ def create_zone(name, view_name) -> dns.zone.Zone:
zone = dns.zone.Zone(origin)
zone.rdclass = dns.rdataclass.IN
try:
# get zones from netbox
nb_zones = Zone.objects.filter(
view__name=view_name, active=True
@@ -120,6 +88,95 @@ def create_zone(name, view_name) -> dns.zone.Zone:
rdataset = zone.find_rdataset(rid, dns.rdatatype.TXT, create=True)
rdataset.add(rdata, ttl)
zone_root_node = zone.find_node(origin, create=True)
# SOA record
soa_rdataset = _create_soa_rdataset()
zone_root_node.rdatasets.append(soa_rdataset)
# NS record
ns_rdataset = _create_ns_rdataset()
zone_root_node.rdatasets.append(ns_rdataset)
# version.catz. record
version_rdataset = _create_version_rdataset()
zone_version_node = zone.find_node(
dns.name.from_text("version", origin), create=True
)
zone_version_node.rdatasets.append(version_rdataset)
return zone
except OperationalError as e:
logger.error(f"ERROR: Unable to create Catalog Zone: {e}")
close_old_connections()
return None
def _init_soa_serial() -> None:
try:
IntegerKeyValueSetting.objects.get(key="catalog-zone-soa-serial")
logger.info("Catalog zone SOA serial number loaded from database")
except IntegerKeyValueSetting.DoesNotExist:
IntegerKeyValueSetting.objects.create(key="catalog-zone-soa-serial", value=1)
logger.debug(
"Catalog zone SOA serial number was not set in the database. Set to 1"
)
except OperationalError as e:
logger.error(f"ERROR: Unable to initialize the Catalog Zone's SOA serial: {e}")
close_old_connections()
def _generate_member_identifier() -> str:
return b32encode(uuid4().bytes)[0:26].lower().decode("UTF-8")
def update_member_identifier(zone: Zone) -> None:
try:
CatalogZoneMemberIdentifier.objects.update_or_create(
zone=zone,
defaults={"name": _generate_member_identifier()},
)
except OperationalError as e:
logger.error(f"ERROR: Unable to update Catalog Zone member identifier: {e}")
close_old_connections()
def _create_missing_member_identifiers() -> None:
try:
existing_zone_ids = CatalogZoneMemberIdentifier.objects.values_list(
"zone_id", flat=True
)
missing_zones = Zone.objects.exclude(id__in=existing_zone_ids)
new_objects = [
CatalogZoneMemberIdentifier(
zone=zone,
name=_generate_member_identifier(),
)
for zone in missing_zones
]
for identifier in new_objects:
logger.debug(
f"Zone {identifier.zone} missing catz member identifier. Creating..."
)
CatalogZoneMemberIdentifier.objects.bulk_create(
new_objects,
ignore_conflicts=False,
)
except OperationalError as e:
logger.error(f"ERROR: Could not create catz member identifier: {e}")
close_old_connections()
def _create_soa_rdataset() -> dns.rdataset:
try:
serial = IntegerKeyValueSetting.objects.get(key="catalog-zone-soa-serial").value
# SOA Record components
ttl = 0
rclass = dns.rdataclass.IN
@@ -132,50 +189,33 @@ def create_zone(name, view_name) -> dns.zone.Zone:
minimum = 0
# Create SOA rdata object
soa_rdata = dns.rdata.from_text(
rdata = dns.rdata.from_text(
rclass,
rtype,
f"{mname} {rname} {soa_serial} {refresh} {retry} {expire} {minimum}",
f"{mname} {rname} {serial} {refresh} {retry} {expire} {minimum}",
)
# Create Rdataset and add the RDATA to it
soa_rdataset = dns.rdataset.Rdataset(rclass, rtype)
soa_rdataset.add(soa_rdata, ttl)
rdataset = dns.rdataset.Rdataset(rclass, rtype)
rdataset.add(rdata, ttl)
return rdataset
# Add to the origin node in the zone
node = zone.find_node(origin, create=True)
node.rdatasets.append(soa_rdataset)
except OperationalError as e:
logger.error(f"ERROR: Unable to access catz SOA record in database: {e}")
close_old_connections()
def _create_ns_rdataset() -> dns.rdataset:
# NS record for catz.
ns_name = dns.name.from_text("invalid", dns.name.root)
ns_rdata = dns.rdata.from_text(dns.rdataclass.IN, dns.rdatatype.NS, str(ns_name))
ns_rdataset = dns.rdataset.Rdataset(dns.rdataclass.IN, dns.rdatatype.NS)
ns_rdataset.add(ns_rdata, 0)
# Add to node (catz. is the origin)
ns_node = zone.find_node(origin, create=True)
ns_node.rdatasets.append(ns_rdataset)
# TXT record for version.catz.
version_name = dns.name.from_text("version", origin)
txt_rdata = dns.rdata.from_text(dns.rdataclass.IN, dns.rdatatype.TXT, '"2"')
txt_rdataset = dns.rdataset.Rdataset(dns.rdataclass.IN, dns.rdatatype.TXT)
txt_rdataset.add(txt_rdata, 0)
# Add to node version.catz.
txt_node = zone.find_node(version_name, create=True)
txt_node.rdatasets.append(txt_rdataset)
return zone
name = dns.name.from_text("invalid", dns.name.root)
rdata = dns.rdata.from_text(dns.rdataclass.IN, dns.rdatatype.NS, str(name))
rdataset = dns.rdataset.Rdataset(dns.rdataclass.IN, dns.rdatatype.NS)
rdataset.add(rdata, 0)
return rdataset
def _generate_member_identifier() -> str:
return b32encode(uuid4().bytes)[0:26].lower().decode("UTF-8")
def update_member_identifier(zone: Zone) -> None:
CatalogZoneMemberIdentifier.objects.update_or_create(
zone=zone,
defaults={"name": _generate_member_identifier()},
)
def _create_version_rdataset() -> dns.rdataset:
rdata = dns.rdata.from_text(dns.rdataclass.IN, dns.rdatatype.TXT, '"2"')
rdataset = dns.rdataset.Rdataset(dns.rdataclass.IN, dns.rdatatype.TXT)
rdataset.add(rdata, 0)
return rdataset
@@ -1,8 +1,3 @@
import os
import dns.zone
import dns.rdatatype
import dns.rdataclass
import dns.exception
import netbox_dns.models
from netbox_dns_bridge.utils import export_bind_zone_file
from django.core.management.base import BaseCommand, CommandError
@@ -24,10 +19,6 @@ class Command(BaseCommand):
)
def handle(self, *args, **options):
# if len(options) < 2:
# print("export-zone <zone name> <file path>")
# sys.exit(1)
# Load parameters
view_name = options["view"]
zone_name = options["zone"]
@@ -48,13 +39,11 @@ class Command(BaseCommand):
if nb_zone:
export_bind_zone_file(nb_zone, file_path=file_path)
else:
print("Zone not found in Netbox. Aborting")
sys.exit(1)
except Exception as e:
raise CommandError(f"Failed to export zone: {e}")
self.stdout.write(
self.style.SUCCESS(f"Zone '{zone_name}' exported to '{file_path}'")
)
else:
self.stderr.write("Zone not found in Netbox. Aborting")
except Exception as e:
raise CommandError(f"Failed to export zone: {e}")
@@ -1,8 +1,4 @@
import os
import dns.zone
import dns.rdatatype
import dns.rdataclass
import dns.exception
import netbox_dns.models
from netbox_dns_bridge.utils import export_bind_zone_file
from django.core.management.base import BaseCommand, CommandError
@@ -9,36 +9,24 @@ import dns.rdataclass
import dns.rdtypes
import dns.exception
import dns.renderer
import logging
from django.core.management.base import BaseCommand
from django.conf import settings
from django.db import close_old_connections, OperationalError
from netbox_dns.models import View
from netbox_dns_bridge import catalog_zone_manager as catzm
from netbox_dns_bridge.request_handler import UDPRequestHandler, TCPRequestHandler
from netbox_dns_bridge.dns_server import UDPDNSServer, TCPDNSServer
from netbox_dns_bridge.models import IntegerKeyValueSetting
from netbox_dns_bridge.logger import get_logger
logger = get_logger(__name__)
LOGGER = get_logger(__name__)
SETTINGS = settings.PLUGINS_CONFIG.get("netbox_dns_bridge", {})
class Command(BaseCommand):
help = "Run a minimal AXFR DNS server using data from NetBox DNS plugin"
def load_settings(self):
self.settings = settings.PLUGINS_CONFIG.get("netbox_dns_bridge", None)
if not self.settings:
raise RuntimeError(
"Command failed to initialize due to missing settings. Terminating Netbox."
)
self.tsig_keys = self.settings.get("tsig_keys", None)
if not self.tsig_keys:
raise RuntimeError("tsig_keys variable not set in plugin settings.")
# Load TSIG keys and map them to views
def load_tsig_key_settings(self):
def _load_tsig_key_settings(self):
self.keyring = {}
self.tsig_view_map = {}
@@ -48,7 +36,7 @@ class Command(BaseCommand):
algorithm_str = data.get("algorithm", "hmac-sha256")
if not raw_key_name or not secret:
logger.error(
LOGGER.error(
f"Skipping TSIG key for view {view_name}: missing keyname or secret."
)
continue
@@ -56,10 +44,12 @@ class Command(BaseCommand):
try:
nb_view = View.objects.get(name=view_name)
except View.DoesNotExist:
logger.error(
LOGGER.error(
f"Skipping TSIG key {raw_key_name}: view '{view_name}' not found."
)
continue
except OperationalError:
close_old_connections()
# Normalize key name to absolute DNS name
key_name_obj = dns.name.from_text(raw_key_name, origin=None).canonicalize()
@@ -71,11 +61,11 @@ class Command(BaseCommand):
name=key_name_obj, secret=secret, algorithm=algorithm_str
)
self.tsig_view_map[key_name_str] = nb_view
logger.info(f"Loaded TSIG key {key_name_str} for view {nb_view.name}")
LOGGER.info(f"Loaded TSIG key {key_name_str} for view {nb_view.name}")
if not self.keyring:
msg = "No TSIG keys found in database."
logger.critical(msg)
LOGGER.critical(msg)
raise RuntimeError(msg)
def add_arguments(self, parser):
@@ -92,9 +82,11 @@ class Command(BaseCommand):
address = options["address"]
catzm.init()
# Initialize settings
self.load_settings()
self.load_tsig_key_settings()
self.tsig_keys = SETTINGS.get("tsig_keys", None)
if not self.tsig_keys:
raise RuntimeError("tsig_keys variable not set in plugin settings.")
self._load_tsig_key_settings()
udp_server = UDPDNSServer(
(address, port), UDPRequestHandler, self.keyring, self.tsig_view_map
@@ -104,15 +96,15 @@ class Command(BaseCommand):
(address, port), TCPRequestHandler, self.keyring, self.tsig_view_map
)
def run_udp_server(server):
logger.info(f"Query endpoint listening on {address} udp/{port}")
def _run_udp_server(server):
LOGGER.info(f"Query endpoint listening on {address} udp/{port}")
server.serve_forever()
udp_thread = threading.Thread(
target=run_udp_server, args=(udp_server,), daemon=True
target=_run_udp_server, args=(udp_server,), daemon=True
)
udp_thread.start()
logger.info(f"Query endpoint listening on {address} tcp/{port}")
LOGGER.info(f"Query endpoint listening on {address} tcp/{port}")
tcp_server.serve_forever()
+6 -2
View File
@@ -6,6 +6,7 @@ import dns.rdatatype
import dns.tsig
from django.conf import settings
from django.utils import timezone
from django.db import close_old_connections, OperationalError
from netbox.jobs import JobRunner
from netbox_dns.models import View, Zone
from .logger import get_logger
@@ -48,10 +49,10 @@ class SendDNSNotify(JobRunner):
view_name = kwargs["view_name"]
zone_name = kwargs["zone_name"]
try:
view = View.objects.get(name=view_name)
tsig_key = self._load_tsig_key(view_name)
cutoff_hours = SETTINGS.get("notify_client_dead_after_hours", 24)
cutoff_hours = SETTINGS.get("notify_client_alive_threshold_hours", 24)
seen_cutoff = timezone.now() - timezone.timedelta(hours=cutoff_hours)
clients = SeenTransferClients.objects.filter(
view=view, last_seen__gte=seen_cutoff
@@ -73,6 +74,9 @@ class SendDNSNotify(JobRunner):
self.logger.error(
f"NOTIFY failed for {client.source_ip} zone {name}: {e}"
)
except OperationalError as e:
self.logger.error(f"NOTIFY failed due to unexpected error: {e}")
close_old_connections()
def schedule(zone: Zone):
+32 -23
View File
@@ -12,13 +12,16 @@ import dns.exception
import dns.renderer
from .logger import get_logger
from django.utils import timezone
from django.db import close_old_connections, OperationalError
from django.conf import settings
from netbox_dns.models import Zone, Record, View
from netbox_dns_bridge import catalog_zone_manager as catzm
from .models import SeenTransferClients
logger = get_logger(__name__)
LOGGER = get_logger(__name__)
SETTINGS = settings.PLUGINS_CONFIG["netbox_dns_bridge"]
class DNSBaseRequestHandler(socketserver.BaseRequestHandler):
def __init__(self, request, client_address, server) -> None:
self.MAX_WIRE = 65535
@@ -34,16 +37,11 @@ class DNSBaseRequestHandler(socketserver.BaseRequestHandler):
view__name=view_name,
active=True,
)
except Zone.DoesNotExist:
return None
# Build DNS zone
zone = dns.zone.Zone(zone_name, dns.name.root)
zone.rdclass = dns.rdataclass.IN
nb_records = Record.objects.filter(
zone=nb_zone, active=True
)
nb_records = Record.objects.filter(zone=nb_zone, active=True)
rdatasets_dict = {}
@@ -109,13 +107,19 @@ class DNSBaseRequestHandler(socketserver.BaseRequestHandler):
# Check if the rdataset has any rdata before creating an RRset
if not rdataset:
logger.debug(f"Skipping empty rdataset for {name} {rdtype}")
LOGGER.debug(f"Skipping empty rdataset for {name} {rdtype}")
continue # Skip empty rdataset
# Replace the rdataset for the given name and type
zone.replace_rdataset(name, rdataset)
return zone
except Zone.DoesNotExist:
return None
except OperationalError as e:
LOGGER.error(f"DB ERROR: {e}")
close_old_connections()
def _deny_request_bad_tsig(self, wire, tsig_error: dns.rcode) -> None:
# Use empty keyring to parse TSIG without validating
query = dns.message.from_wire(
@@ -146,12 +150,17 @@ class DNSBaseRequestHandler(socketserver.BaseRequestHandler):
def _track_seen_client(self, source_ip: str, view: View) -> None:
if SETTINGS.get("notify_clients", False):
try:
SeenTransferClients.objects.update_or_create(
source_ip=source_ip,
view=view,
defaults={"last_seen": timezone.now()},
)
except OperationalError as e:
LOGGER.error(f"DB ERROR: {e}")
close_old_connections()
def _handle_soa_request(self, query, soa_rrset, zone, peer, nb_view, dname) -> None:
# We assume that the SOA rdataset has at least one record (it usually does).
soa_rdata = soa_rrset[0] # Get the first SOA record
@@ -185,11 +194,11 @@ class DNSBaseRequestHandler(socketserver.BaseRequestHandler):
data = response.to_wire(max_size=512)
self._send_response(data)
logger.info(f"{peer} SOA {nb_view.name}/{dname}")
LOGGER.info(f"{peer} SOA {nb_view.name}/{dname}")
def _handle_axfr_request(self, query, zone, peer, nb_view, dname) -> None:
if query.keyname not in self.server.keyring:
logger.error(f"AXFR aborted: keyname {query.keyname} not in keyring")
LOGGER.error(f"AXFR aborted: keyname {query.keyname} not in keyring")
self._deny_request(query)
return
@@ -262,7 +271,7 @@ class DNSBaseRequestHandler(socketserver.BaseRequestHandler):
try:
r.add_rrset(dns.renderer.ANSWER, rrset)
except dns.exception.TooBig:
logger.error(
LOGGER.error(
f"RRset {rrset.name}/{dns.rdatatype.to_text(rrset.rdtype)} "
f"exceeds MAX_WIRE ({self.MAX_WIRE}) and cannot be sent; "
f"skipping."
@@ -283,7 +292,7 @@ class DNSBaseRequestHandler(socketserver.BaseRequestHandler):
)
wire = r.get_wire()
self._send_response(wire)
logger.info(f"{peer} AXFR {nb_view.name}/{dname}")
LOGGER.info(f"{peer} AXFR {nb_view.name}/{dname}")
def _handle_dns_query(self, wire) -> None:
peer = self.client_address[0]
@@ -296,17 +305,17 @@ class DNSBaseRequestHandler(socketserver.BaseRequestHandler):
)
except dns.tsig.BadSignature as e:
logger.warning(f"Request denied from {peer} failed TSIG verification: {e}")
LOGGER.warning(f"Request denied from {peer} failed TSIG verification: {e}")
self._deny_request_bad_tsig(wire, dns.rcode.BADSIG)
return
except (dns.message.UnknownTSIGKey, dns.tsig.BadAlgorithm) as e:
logger.warning(f"Request denied from {peer} with bad TSIG key: {e}")
LOGGER.warning(f"Request denied from {peer} with bad TSIG key: {e}")
self._deny_request_bad_tsig(wire, dns.rcode.BADKEY)
return
except Exception as e:
logger.error("Error parsing query: ", e)
LOGGER.error("Error parsing query: ", e)
return
# If there was no question in the query, refuse
@@ -321,7 +330,7 @@ class DNSBaseRequestHandler(socketserver.BaseRequestHandler):
# Only process AXFR/SOA queris
if qtype not in (dns.rdatatype.AXFR, dns.rdatatype.SOA):
logger.warning(
LOGGER.warning(
f"Request denied from {peer}: Request was not AXFR or SOA (Type: {qtype})"
)
self._deny_request(query)
@@ -329,7 +338,7 @@ class DNSBaseRequestHandler(socketserver.BaseRequestHandler):
# Identify TSIG key used
if not query.had_tsig:
logger.warning(f"Request denied from {peer}: No TSIG key used")
LOGGER.warning(f"Request denied from {peer}: No TSIG key used")
self._deny_request(query)
return
@@ -338,7 +347,7 @@ class DNSBaseRequestHandler(socketserver.BaseRequestHandler):
# Check if the key matches a view
nb_view = self.server.tsig_view_map.get(key_name)
if not nb_view:
logger.warning(
LOGGER.warning(
f"Request denied from {peer}: {key_name} does not match a view"
)
self._deny_request(query)
@@ -351,14 +360,14 @@ class DNSBaseRequestHandler(socketserver.BaseRequestHandler):
zone = self._getZoneFromNB(dname, nb_view.name)
# When zone was not found, let client know
if not zone:
logger.warning(f"Zone {dname} not found in view {nb_view.name}")
LOGGER.warning(f"Zone {dname} not found in view {nb_view.name}")
self._deny_request(query)
return
# Retrieve the existing SOA record from the Zone
soa_rrset = zone.get_rdataset(zone.origin, dns.rdatatype.SOA)
if soa_rrset is None:
logger.error(f"Zone {dname} has no SOA — aborting")
LOGGER.error(f"Zone {dname} has no SOA — aborting")
return
if qtype == dns.rdatatype.SOA:
@@ -383,7 +392,7 @@ class UDPRequestHandler(DNSBaseRequestHandler):
try:
self._handle_dns_query(data)
except Exception as e:
logger.error(f"Error handling request from {peer}: {e}")
LOGGER.error(f"Error handling request from {peer}: {e}")
import traceback
traceback.print_exc()
@@ -425,9 +434,9 @@ class TCPRequestHandler(DNSBaseRequestHandler):
self._handle_dns_query(wire)
except socket.timeout:
logger.debug(f"Connection from {peer} timed out")
LOGGER.debug(f"Connection from {peer} timed out")
except Exception as e:
logger.error(f"Error handling request from {peer}: {e}")
LOGGER.error(f"Error handling request from {peer}: {e}")
import traceback
traceback.print_exc()