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pvc/node-daemon/pvcd/DNSAggregatorInstance.py
Joshua M. Boniface 0d2e22a111 Normalize all static networks with bridges 
Modifies the storage and upstream networks to mirror the cluster
network, with a bridge on top of the underlying specified dev, and all
IPs bound to the bridge.

Allows creating VMs in the storage or upstream networks, as well as the
cluster network, should the administrator choose to do so (manually).
2020-01-12 19:04:31 -05:00

532 lines
22 KiB
Python
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#!/usr/bin/env python3
# DNSAggregatorInstance.py - Class implementing a DNS aggregator and run by pvcd
# Part of the Parallel Virtual Cluster (PVC) system
#
# Copyright (C) 2018-2020 Joshua M. Boniface <joshua@boniface.me>
#
# This program 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 3 of the License, or
# (at your option) any later version.
#
# This program 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 this program. If not, see <https://www.gnu.org/licenses/>.
#
###############################################################################
import os
import sys
import time
import threading
import dns.zone
import dns.query
import psycopg2
import pvcd.log as log
import pvcd.zkhandler as zkhandler
import pvcd.common as common
class DNSAggregatorInstance(object):
# Initialization function
def __init__(self, zk_conn, config, logger):
self.zk_conn = zk_conn
self.config = config
self.logger = logger
self.dns_networks = dict()
self.is_active = False
self.dns_server_daemon = PowerDNSInstance(self)
self.dns_axfr_daemon = AXFRDaemonInstance(self)
# Start up the PowerDNS instance
def start_aggregator(self):
# Restart the SQL connection
self.dns_server_daemon.start()
self.dns_axfr_daemon.start()
self.is_active = True
# Stop the PowerDNS instance
def stop_aggregator(self):
self.is_active = False
self.dns_axfr_daemon.stop()
self.dns_server_daemon.stop()
def add_network(self, network):
self.dns_networks[network] = DNSNetworkInstance(self, network)
self.dns_networks[network].add_network()
self.dns_axfr_daemon.update_networks(self.dns_networks)
def remove_network(self, network):
if self.dns_networks[network]:
self.dns_networks[network].remove_network()
del self.dns_networks[network]
self.dns_axfr_daemon.update_networks(self.dns_networks)
class PowerDNSInstance(object):
# Initialization function
def __init__(self, aggregator):
self.aggregator = aggregator
self.config = self.aggregator.config
self.logger = self.aggregator.logger
self.dns_server_daemon = None
# Floating upstreams
self.vni_ipaddr, self.vni_cidrnetmask = self.config['vni_floating_ip'].split('/')
self.upstream_ipaddr, self.upstream_cidrnetmask = self.config['upstream_floating_ip'].split('/')
def start(self):
self.logger.out(
'Starting PowerDNS zone aggregator',
state='i'
)
# Define the PowerDNS config
dns_configuration = [
# Option # Explanation
'--no-config',
'--daemon=no', # Start directly
'--guardian=yes', # Use a guardian
'--disable-syslog=yes', # Log only to stdout (which is then captured)
'--disable-axfr=no', # Allow AXFRs
'--allow-axfr-ips=0.0.0.0/0', # Allow AXFRs to anywhere
'--local-address={},{}'.format(self.vni_ipaddr, self.upstream_ipaddr),
# Listen on floating IPs
'--local-port=53', # On port 53
'--log-dns-details=on', # Log details
'--loglevel=3', # Log info
'--master=yes', # Enable master mode
'--slave=yes', # Enable slave mode
'--slave-renotify=yes', # Renotify out for our slaved zones
'--version-string=powerdns', # Set the version string
'--default-soa-name=dns.pvc.local', # Override dnsmasq's invalid name
'--socket-dir={}'.format(self.config['pdns_dynamic_directory']),
# Standard socket directory
'--launch=gpgsql', # Use the PostgreSQL backend
'--gpgsql-host={}'.format(self.config['pdns_postgresql_host']),
# PostgreSQL instance
'--gpgsql-port={}'.format(self.config['pdns_postgresql_port']),
# Default port
'--gpgsql-dbname={}'.format(self.config['pdns_postgresql_dbname']),
# Database name
'--gpgsql-user={}'.format(self.config['pdns_postgresql_user']),
# User name
'--gpgsql-password={}'.format(self.config['pdns_postgresql_password']),
# User password
'--gpgsql-dnssec=no', # Do DNSSEC elsewhere
]
# Start the pdns process in a thread
self.dns_server_daemon = common.run_os_daemon(
'/usr/sbin/pdns_server {}'.format(
' '.join(dns_configuration)
),
environment=None,
logfile='{}/pdns-aggregator.log'.format(self.config['pdns_log_directory'])
)
if self.dns_server_daemon:
self.logger.out(
'Successfully started PowerDNS zone aggregator',
state='o'
)
def stop(self):
if self.dns_server_daemon:
self.logger.out(
'Stopping PowerDNS zone aggregator',
state='i'
)
# Terminate, then kill
self.dns_server_daemon.signal('term')
time.sleep(0.2)
self.dns_server_daemon.signal('kill')
self.logger.out(
'Successfully stopped PowerDNS zone aggregator',
state='o'
)
class DNSNetworkInstance(object):
# Initialization function
def __init__(self, aggregator, network):
self.aggregator = aggregator
self.config = self.aggregator.config
self.logger = self.aggregator.logger
self.sql_conn = None
self.network = network
# Add a new network to the aggregator database
def add_network(self):
network_domain = self.network.domain
if self.network.ip4_gateway != 'None':
network_gateway = self.network.ip4_gateway
else:
network_gateway = self.network.ip6_gateway
self.logger.out(
'Adding entry for client domain {}'.format(
network_domain
),
prefix='DNS aggregator',
state='o'
)
# Connect to the database
self.sql_conn = psycopg2.connect(
"host='{}' port='{}' dbname='{}' user='{}' password='{}' sslmode='disable'".format(
self.config['pdns_postgresql_host'],
self.config['pdns_postgresql_port'],
self.config['pdns_postgresql_dbname'],
self.config['pdns_postgresql_user'],
self.config['pdns_postgresql_password']
)
)
sql_curs = self.sql_conn.cursor()
# Try to access the domains entry
sql_curs.execute(
"SELECT * FROM domains WHERE name=%s",
(network_domain,)
)
results = sql_curs.fetchone()
# If we got back a result, don't try to add the domain to the DB
if results:
write_domain = False
else:
write_domain = True
# Write the domain to the database if we're active
if self.aggregator.is_active and write_domain:
sql_curs.execute(
"INSERT INTO domains (name, type, account, notified_serial) VALUES (%s, 'MASTER', 'internal', 0)",
(network_domain,)
)
self.sql_conn.commit()
sql_curs.execute(
"SELECT id FROM domains WHERE name=%s",
(network_domain,)
)
domain_id = sql_curs.fetchone()
sql_curs.execute(
"""
INSERT INTO records (domain_id, name, content, type, ttl, prio) VALUES
(%s, %s, %s, %s, %s, %s)
""",
(domain_id, network_domain, 'nsX.{d} root.{d} 1 10800 1800 86400 86400'.format(d=self.config['upstream_domain']), 'SOA', 86400, 0)
)
if self.network.name_servers:
ns_servers = self.network.name_servers
else:
ns_servers = ['pvc-dns.{}'.format(self.config['upstream_domain'])]
for ns_server in ns_servers:
sql_curs.execute(
"""
INSERT INTO records (domain_id, name, content, type, ttl, prio) VALUES
(%s, %s, %s, %s, %s, %s)
""",
(domain_id, network_domain, ns_server, 'NS', 86400, 0)
)
self.sql_conn.commit()
self.sql_conn.close()
self.sql_conn = None
# Remove a deleted network from the aggregator database
def remove_network(self):
network_domain = self.network.domain
self.logger.out(
'Removing entry for client domain {}'.format(
network_domain
),
prefix='DNS aggregator',
state='o'
)
# Connect to the database
self.sql_conn = psycopg2.connect(
"host='{}' port='{}' dbname='{}' user='{}' password='{}' sslmode='disable'".format(
self.config['pdns_postgresql_host'],
self.config['pdns_postgresql_port'],
self.config['pdns_postgresql_dbname'],
self.config['pdns_postgresql_user'],
self.config['pdns_postgresql_password']
)
)
sql_curs = self.sql_conn.cursor()
# Get the domain ID
sql_curs.execute(
"SELECT id FROM domains WHERE name=%s",
(network_domain,)
)
domain_id = sql_curs.fetchone()
# Delete the domain from the database if we're active
if self.aggregator.is_active and domain_id:
sql_curs.execute(
"DELETE FROM domains WHERE id=%s",
(domain_id,)
)
sql_curs.execute(
"DELETE FROM records WHERE domain_id=%s",
(domain_id,)
)
self.sql_conn.commit()
self.sql_conn.close()
self.sql_conn = None
class AXFRDaemonInstance(object):
# Initialization function
def __init__(self, aggregator):
self.aggregator = aggregator
self.config = self.aggregator.config
self.logger = self.aggregator.logger
self.dns_networks = self.aggregator.dns_networks
self.thread_stopper = threading.Event()
self.thread = None
self.sql_conn = None
def update_networks(self, dns_networks):
self.dns_networks = dns_networks
def start(self):
# Create the thread
self.thread_stopper.clear()
self.thread = threading.Thread(target=self.run, args=(), kwargs={})
# Start a local instance of the SQL connection
# Trying to use the instance from the main DNS Aggregator can result in connection failures
# after the leader transitions
self.sql_conn = psycopg2.connect(
"host='{}' port='{}' dbname='{}' user='{}' password='{}' sslmode='disable'".format(
self.config['pdns_postgresql_host'],
self.config['pdns_postgresql_port'],
self.config['pdns_postgresql_dbname'],
self.config['pdns_postgresql_user'],
self.config['pdns_postgresql_password']
)
)
# Start the thread
self.thread.start()
def stop(self):
self.thread_stopper.set()
if self.sql_conn:
self.sql_conn.close()
self.sql_conn = None
def run(self):
# Wait for all the DNSMASQ instances to actually start
time.sleep(5)
while not self.thread_stopper.is_set():
# We do this for each network
for network, instance in self.dns_networks.items():
zone_modified = False
# Set up our SQL cursor
sql_curs = self.sql_conn.cursor()
# Set up our basic variables
domain = network.domain
if network.ip4_gateway != 'None':
dnsmasq_ip = network.ip4_gateway
else:
dnsmasq_ip = network.ip6_gateway
#
# Get an AXFR from the dnsmasq instance and list of records
#
try:
axfr = dns.query.xfr(dnsmasq_ip, domain, lifetime=5.0)
z = dns.zone.from_xfr(axfr)
records_raw = [z[n].to_text(n) for n in z.nodes.keys()]
except Exception as e:
if self.config['debug']:
print('{} {} ({})'.format(e, dnsmasq_ip, domain))
continue
# Fix the formatting because it's useless
# reference: ['@ 600 IN SOA . . 4 1200 180 1209600 600\n@ 600 IN NS .', 'test3 600 IN A 10.1.1.203\ntest3 600 IN AAAA 2001:b23e:1113:0:5054:ff:fe5c:f131', etc.]
# We don't really care about dnsmasq's terrible SOA or NS records which are in [0]
string_records = '\n'.join(records_raw[1:])
# Split into individual records
records_new = list()
for element in string_records.split('\n'):
if element:
record = element.split()
# Handle space-containing data elements
if domain not in record[0]:
name = '{}.{}'.format(record[0], domain)
else:
name = record[0]
entry = '{} {} IN {} {}'.format(name, record[1], record[3], ' '.join(record[4:]))
records_new.append(entry)
#
# Get the current zone from the database
#
try:
sql_curs.execute(
"SELECT id FROM domains WHERE name=%s",
(domain,)
)
domain_id = sql_curs.fetchone()
sql_curs.execute(
"SELECT * FROM records WHERE domain_id=%s",
(domain_id,)
)
results = list(sql_curs.fetchall())
if self.config['debug']:
print('SQL query results: {}'.format(results))
except Exception as e:
self.logger.out('ERROR: Failed to obtain DNS records from database: {}'.format(e))
# Fix the formatting because it's useless for comparison
# reference: ((10, 28, 'testnet01.i.bonilan.net', 'SOA', 'nsX.pvc.local root.pvc.local 1 10800 1800 86400 86400', 86400, 0, None, 0, None, 1), etc.)
records_old = list()
records_old_ids = list()
if not results:
if self.config['debug']:
print('No results found, skipping.')
continue
for record in results:
# Skip the non-A
r_id = record[0]
r_name = record[2]
r_ttl = record[5]
r_type = record[3]
r_data = record[4]
# Assemble a list element in the same format as the AXFR data
entry = '{} {} IN {} {}'.format(r_name, r_ttl, r_type, r_data)
if self.config['debug']:
print('Found record: {}'.format(entry))
# Skip non-A or AAAA records
if r_type != 'A' and r_type != 'AAAA':
if self.config['debug']:
print('Skipping record {}, not A or AAAA: "{}"'.format(entry, r_type))
continue
records_old.append(entry)
records_old_ids.append(r_id)
records_new.sort()
records_old.sort()
if self.config['debug']:
print('New: {}'.format(records_new))
print('Old: {}'.format(records_old))
# Find the differences between the lists
# Basic check one: are they completely equal
if records_new != records_old:
# Get set elements
in_new = set(records_new)
in_old = set(records_old)
in_new_not_in_old = in_new - in_old
in_old_not_in_new = in_old - in_new
if self.config['debug']:
print('New but not old: {}'.format(in_new_not_in_old))
print('Old but not new: {}'.format(in_old_not_in_new))
# Go through the old list
remove_records = list() # list of database IDs
for i in range(len(records_old)):
record_id = records_old_ids[i]
record = records_old[i]
splitrecord = records_old[i].split()
# If the record is not in the new list, remove it
if record in in_old_not_in_new:
remove_records.append(record_id)
# Go through the new elements
for newrecord in in_new_not_in_old:
splitnewrecord = newrecord.split()
# If there's a name and type match with different content, remove the old one
if splitrecord[0] == splitnewrecord[0] and splitrecord[3] == splitnewrecord[3]:
remove_records.append(record_id)
changed = False
if len(remove_records) > 0:
# Remove the invalid old records
for record_id in remove_records:
if self.config['debug']:
print('Removing record: {}'.format(record_id))
sql_curs.execute(
"DELETE FROM records WHERE id=%s",
(record_id,)
)
changed = True
if len(in_new_not_in_old) > 0:
# Add the new records
for record in in_new_not_in_old:
# [NAME, TTL, 'IN', TYPE, DATA]
record = record.split()
r_name = record[0]
r_ttl = record[1]
r_type = record[3]
r_data = record[4]
if self.config['debug']:
print('Add record: {}'.format(name))
try:
sql_curs.execute(
"INSERT INTO records (domain_id, name, ttl, type, prio, content) VALUES (%s, %s, %s, %s, %s, %s)",
(domain_id, r_name, r_ttl, r_type, 0, r_data)
)
changed = True
except psycopg2.IntegrityError as e:
if self.config['debug']:
print('Failed to add record due to {}: {}'.format(e, name))
if changed:
# Increase SOA serial
sql_curs.execute(
"SELECT content FROM records WHERE domain_id=%s AND type='SOA'",
(domain_id,)
)
soa_record = list(sql_curs.fetchone())[0].split()
current_serial = int(soa_record[2])
new_serial = current_serial + 1
soa_record[2] = str(new_serial)
if self.config['debug']:
print('Records changed; bumping SOA: {}'.format(new_serial))
sql_curs.execute(
"UPDATE records SET content=%s WHERE domain_id=%s AND type='SOA'",
(' '.join(soa_record), domain_id)
)
# Commit all the previous changes
if self.config['debug']:
print('Committing database changes and reloading PDNS')
try:
self.sql_conn.commit()
except Exception as e:
self.logger.out('ERROR: Failed to commit DNS aggregator changes: {}'.format(e), state='e')
# Reload the domain
common.run_os_command(
'/usr/bin/pdns_control --socket-dir={} reload {}'.format(
self.config['pdns_dynamic_directory'],
domain
),
background=False
)
# Wait for 10 seconds
time.sleep(10)
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