deb-designate/designate/mdns/notify.py
Doug Hellmann 1ff8469ef7 Drop use of 'oslo' namespace package
The Oslo libraries have moved all of their code out of the 'oslo'
namespace package into per-library packages. The namespace package was
retained during kilo for backwards compatibility, but will be removed by
the liberty-2 milestone. This change removes the use of the namespace
package, replacing it with the new package names.

The patches in the libraries will be put on hold until application
patches have landed, or L2, whichever comes first. At that point, new
versions of the libraries without namespace packages will be released as
a major version update.

Please merge this patch, or an equivalent, before L2 to avoid problems
with those library releases.

Blueprint: remove-namespace-packages
https://blueprints.launchpad.net/oslo-incubator/+spec/remove-namespace-packages

Change-Id: Iae62b48993eef3b31420f8cc245a55f5e303c4fc
2015-04-28 18:32:15 +00:00

275 lines
12 KiB
Python

# Copyright (c) 2014 Rackspace Hosting
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import time
import eventlet
import dns
import dns.rdataclass
import dns.rdatatype
import dns.exception
import dns.flags
import dns.rcode
import dns.message
import dns.opcode
from oslo_config import cfg
from oslo_log import log as logging
from designate.mdns import base
from designate.i18n import _LI
from designate.i18n import _LW
dns_query = eventlet.import_patched('dns.query')
LOG = logging.getLogger(__name__)
CONF = cfg.CONF
class NotifyEndpoint(base.BaseEndpoint):
RPC_API_VERSION = '1.1'
RPC_API_NAMESPACE = 'notify'
def notify_zone_changed(self, context, domain, nameserver, timeout,
retry_interval, max_retries, delay):
"""
:param context: The user context.
:param domain: The designate domain object. This contains the domain
name.
:param nameserver: A notify is sent to nameserver.host:nameserver.port.
:param timeout: The time (in seconds) to wait for a NOTIFY response
from server.
:param retry_interval: The time (in seconds) between retries.
:param max_retries: The maximum number of retries mindns would do for
sending a NOTIFY message. After this many retries, mindns gives up.
:param delay: The time to wait before sending the first NOTIFY request.
:return: a tuple of (response, current_retry) where
response is the response on success or None on failure.
current_retry is the current retry number.
The return value is just used for testing and not by pool manager.
"""
time.sleep(delay)
return self._make_and_send_dns_message(
domain, nameserver, timeout, retry_interval, max_retries,
notify=True)
def poll_for_serial_number(self, context, domain, nameserver, timeout,
retry_interval, max_retries, delay):
"""
:param context: The user context.
:param domain: The designate domain object. This contains the domain
name. domain.serial = expected_serial
:param nameserver: nameserver.host:nameserver.port is checked for an
updated serial number.
:param timeout: The time (in seconds) to wait for a SOA response from
nameserver.
:param retry_interval: The time (in seconds) between retries.
:param max_retries: The maximum number of retries mindns would do for
an expected serial number. After this many retries, mindns returns
an ERROR.
:param delay: The time to wait before sending the first request.
:return: The pool manager is informed of the status with update_status.
"""
(status, actual_serial, retries) = self.get_serial_number(
context, domain, nameserver, timeout, retry_interval, max_retries,
delay)
self.pool_manager_api.update_status(
context, domain, nameserver, status, actual_serial)
def get_serial_number(self, context, domain, nameserver, timeout,
retry_interval, max_retries, delay):
"""
:param context: The user context.
:param domain: The designate domain object. This contains the domain
name. domain.serial = expected_serial
:param nameserver: nameserver.host:nameserver.port is checked for an
updated serial number.
:param timeout: The time (in seconds) to wait for a SOA response from
nameserver.
:param retry_interval: The time (in seconds) between retries.
:param max_retries: The maximum number of retries mindns would do for
an expected serial number. After this many retries, mindns returns
an ERROR.
:param delay: The time to wait before sending the first request.
:return: a tuple of (status, actual_serial, retries)
status is either "SUCCESS" or "ERROR".
actual_serial is either the serial number returned in the SOA
message from the nameserver or None.
retries is the number of retries left.
The return value is just used for testing and not by pool manager.
The pool manager is informed of the status with update_status.
"""
actual_serial = None
status = 'ERROR'
retries = max_retries
time.sleep(delay)
while (True):
(response, retry) = self._make_and_send_dns_message(
domain, nameserver, timeout, retry_interval, retries)
if response and response.rcode() in (
dns.rcode.NXDOMAIN, dns.rcode.REFUSED, dns.rcode.SERVFAIL):
status = 'NO_DOMAIN'
elif response and len(response.answer) == 1 \
and str(response.answer[0].name) == str(domain.name) \
and response.answer[0].rdclass == dns.rdataclass.IN \
and response.answer[0].rdtype == dns.rdatatype.SOA:
# parse the SOA response and get the serial number
rrset = response.answer[0]
actual_serial = rrset.to_rdataset().items[0].serial
if actual_serial is None or actual_serial < domain.serial:
# TODO(vinod): Account for serial number wrap around.
retries = retries - retry
LOG.warn(_LW("Got lower serial for '%(zone)s' to '%(host)s:"
"%(port)s'. Expected:'%(es)d'. Got:'%(as)s'."
"Retries left='%(retries)d'") %
{'zone': domain.name, 'host': nameserver.host,
'port': nameserver.port, 'es': domain.serial,
'as': actual_serial, 'retries': retries})
if retries > 0:
# retry again
time.sleep(retry_interval)
continue
else:
break
else:
# Everything looks good at this point. Return SUCCESS.
status = 'SUCCESS'
break
# Return retries for testing purposes.
return (status, actual_serial, retries)
def _make_and_send_dns_message(self, domain, nameserver, timeout,
retry_interval, max_retries, notify=False):
"""
:param domain: The designate domain object. This contains the domain
name.
:param server: The destination for the dns message is
server.host:server.port.
:param timeout: The time (in seconds) to wait for a response from
destination.
:param retry_interval: The time (in seconds) between retries.
:param max_retries: The maximum number of retries mindns would do for
a response. After this many retries, the function returns.
:param notify: If true, a notify message is constructed else a SOA
message is constructed.
:return: a tuple of (response, current_retry) where
response is the response on success or None on failure.
current_retry is the current retry number
"""
dest_ip = nameserver.host
dest_port = nameserver.port
dns_message = self._make_dns_message(domain.name, notify=notify)
retry = 0
response = None
while retry < max_retries:
retry = retry + 1
LOG.info(_LI("Sending '%(msg)s' for '%(zone)s' to '%(server)s:"
"%(port)d'.") %
{'msg': 'NOTIFY' if notify else 'SOA',
'zone': domain.name, 'server': dest_ip,
'port': dest_port})
response = self._send_dns_message(
dns_message, dest_ip, dest_port, timeout)
if isinstance(response, dns.exception.Timeout):
LOG.warn(_LW("Got Timeout while trying to send '%(msg)s' for "
"'%(zone)s' to '%(server)s:%(port)d'. Timeout="
"'%(timeout)d' seconds. Retry='%(retry)d'") %
{'msg': 'NOTIFY' if notify else 'SOA',
'zone': domain.name, 'server': dest_ip,
'port': dest_port, 'timeout': timeout,
'retry': retry})
response = None
# retry sending the message if we get a Timeout.
time.sleep(retry_interval)
continue
elif isinstance(response, dns_query.BadResponse):
LOG.warn(_LW("Got BadResponse while trying to send '%(msg)s' "
"for '%(zone)s' to '%(server)s:%(port)d'. Timeout"
"='%(timeout)d' seconds. Retry='%(retry)d'") %
{'msg': 'NOTIFY' if notify else 'SOA',
'zone': domain.name, 'server': dest_ip,
'port': dest_port, 'timeout': timeout,
'retry': retry})
response = None
break
# Check that we actually got a NOERROR in the rcode and and an
# authoritative answer
elif response.rcode() in (dns.rcode.NXDOMAIN, dns.rcode.REFUSED,
dns.rcode.SERVFAIL):
LOG.info(_LI("%(zone)s not found on %(server)s:%(port)d") %
{'zone': domain.name, 'server': dest_ip,
'port': dest_port})
break
elif not (response.flags & dns.flags.AA) or dns.rcode.from_flags(
response.flags, response.ednsflags) != dns.rcode.NOERROR:
LOG.warn(_LW("Failed to get expected response while trying to "
"send '%(msg)s' for '%(zone)s' to '%(server)s:"
"%(port)d'.\nResponse message:\n%(resp)s\n") %
{'msg': 'NOTIFY' if notify else 'SOA',
'zone': domain.name, 'server': dest_ip,
'port': dest_port, 'resp': str(response)})
response = None
break
else:
break
return (response, retry)
def _make_dns_message(self, zone_name, notify=False):
"""
This constructs a SOA query or a dns NOTIFY message.
:param zone_name: The zone name for which a SOA/NOTIFY needs to be
sent.
:param notify: If true, a notify message is constructed else a SOA
message is constructed.
:return: The constructed message.
"""
dns_message = dns.message.make_query(zone_name, dns.rdatatype.SOA)
dns_message.flags = 0
if notify:
dns_message.set_opcode(dns.opcode.NOTIFY)
dns_message.flags |= dns.flags.AA
else:
# Setting the flags to RD causes BIND9 to respond with a NXDOMAIN.
dns_message.set_opcode(dns.opcode.QUERY)
dns_message.flags |= dns.flags.RD
return dns_message
def _send_dns_message(self, dns_message, dest_ip, dest_port, timeout):
"""
:param dns_message: The dns message that needs to be sent.
:param dest_ip: The destination ip of dns_message.
:param dest_port: The destination port of dns_message.
:param timeout: The timeout in seconds to wait for a response.
:return: response or dns.exception.Timeout or dns_query.BadResponse
"""
try:
if not CONF['service:mdns'].all_tcp:
response = dns_query.udp(
dns_message, dest_ip, port=dest_port, timeout=timeout)
else:
response = dns_query.tcp(
dns_message, dest_ip, port=dest_port, timeout=timeout)
return response
except dns.exception.Timeout as timeout:
return timeout
except dns_query.BadResponse as badResponse:
return badResponse