This a pipe backend for PowerDNS to MongoDB written in Python.
Requirements
- pymongo python library
- powerdns min. version 4.x
The MongoDB schema (for example DB: dns / Collection: records)
For SOA records:
{
"name":"example.org",
"type":"SOA",
"content":"",
"ttl": 300,
"primary": "ns1.example.org",
"mail": "admin.example.org",
"serial": 2018030311,
"refresh": 86400,
"retry": 7200,
"expire": 3600000,
"nttl": 3600
}
For standard records:
{
"name":"www.example.org",
"type":"A",
"ttl": 300,
"content": "1.1.1.1"
}
Install PowerDNS
apt install pdns-server pdns-backend-pipe
Install pymongo Library
pip install pymongo
The Backend Script (for example: /opt/pdns/backend.py)
You can download it from GitHub – https://github.com/lanbugs/powerdns_mongodb_backend
Parts of the code based on: https://gist.github.com/sokratisg/10069682
#!/usr/bin/env python
import sys
from pymongo import MongoClient
# Config
mongo_host = "127.0.0.1"
mongo_port = 27017
mongo_db = "dns"
mongo_collation = "records"
class Lookup(object):
ttl = 30
def __init__(self, query):
(_type, qname, qclass, qtype, _id, ip) = query
self.has_result = False
qname_lower = qname.lower()
self.results = []
self.results.append('LOG\t%s-%s-%s-%s-%s-%s' % (_type, qname, qclass, qtype, _id, ip))
self.has_result = True
client = MongoClient(mongo_host, mongo_port, connect=False)
db = client[mongo_db]
coll = db[mongo_collation]
if qtype == "ANY":
records = coll.find({"name": qname_lower})
else:
records = coll.find({"type": qtype, "name": qname_lower})
if records:
for record in records:
if record['type'] == "SOA":
"""
{
"name":"example.org",
"type":"SOA",
"content":"",
"ttl": 300,
"primary": "ns1.example.org",
"mail": "admin.example.org",
"serial": 2018030311,
"refresh": 86400,
"retry": 7200,
"expire": 3600000,
"nttl": 3600
}
"""
try:
self.results.append(
'DATA\t%s\t%s\t%s\t%s\t-1\t%s\t%s\t%s\t%s\t%s\t%s\t%s' % ( qname_lower,
qclass,
qtype,
record['ttl'],
record['primary'],
record['mail'],
record['serial'],
record['refresh'],
record['retry'],
record['expire'],
record['nttl']
))
self.has_result = True
except:
self.results.append('LOG\t %s SOA Record currupt maybe fields are missing.' % qname_lower)
else:
"""
{
"name":"www.example.org",
"type":"A",
"ttl": 300,
"content": "1.1.1.1"
}
"""
self.results.append('DATA\t%s\t%s\t%s\t%d\t-1\t%s' % (
qname_lower, qclass, record['type'], record['ttl'], record['content']))
self.has_result = True
def str_result(self):
if self.has_result:
return '\n'.join(self.results)
else:
return ''
class DNSbackend(object):
def __init__(self, filein, fileout):
self.filein = filein
self.fileout = fileout
self._process_requests()
def _fprint(self, message):
self.fileout.write(message + '\n')
self.fileout.flush()
def _process_requests(self):
first_time = True
while 1:
rawline = self.filein.readline()
if rawline == '':
return
line = rawline.rstrip()
if first_time:
if line == 'HELO\t1':
self._fprint('OK\tPython backend ready.')
else:
rawline = self.filein.readline()
sys.exit(1)
first_time = False
else:
query = line.split('\t')
if len(query) != 6:
self._fprint('LOG\tPowerDNS sent unparseable line')
self._fprint('FAIL')
else:
lookup = Lookup(query)
if lookup.has_result:
pdns_result = lookup.str_result()
self._fprint(pdns_result)
self._fprint('END')
if __name__ == "__main__":
infile = sys.stdin
outfile = sys.stdout
try:
DNSbackend(infile, outfile)
except:
raise
Don`t forget to make the backend.py script executable to the world.
PowerDNS Configuration /etc/powernds/pdns.d/pdns.local.conf
# Here come the local changes the user made, like configuration of # the several backends that exist. launch=pipe pipe-command=/opt/pdns/backend.py
Try…
Launch the PowerDNS service in monitor mode
root@pdnsdev:~# /etc/init.d/pdns monitor Jun 20 21:10:11 Reading random entropy from '/dev/urandom' Jun 20 21:10:11 Loading '/usr/lib/x86_64-linux-gnu/pdns/libpipebackend.so' Jun 20 21:10:11 [PIPEBackend] This is the pipe backend version 4.0.0-alpha2 reporting Jun 20 21:10:11 Loading '/usr/lib/x86_64-linux-gnu/pdns/libbindbackend.so' Jun 20 21:10:11 [bind2backend] This is the bind backend version 4.0.0-alpha2 reporting Jun 20 21:10:11 This is a standalone pdns Jun 20 21:10:11 UDP server bound to 0.0.0.0:53 Jun 20 21:10:11 Unable to enable timestamp reporting for socket Jun 20 21:10:11 UDPv6 server bound to [::]:53 Jun 20 21:10:11 TCP server bound to 0.0.0.0:53 Jun 20 21:10:11 TCPv6 server bound to [::]:53 Jun 20 21:10:11 PowerDNS Authoritative Server 4.0.0-alpha2 (C) 2001-2016 PowerDNS.COM BV Jun 20 21:10:11 Using 64-bits mode. Built using gcc 5.3.1 20160330. Jun 20 21:10:11 PowerDNS comes with ABSOLUTELY NO WARRANTY. This is free software, and you are welcome to redistribute it according to the terms of the GPL version 2. Jun 20 21:10:11 Set effective group id to 118 Jun 20 21:10:11 Set effective user id to 112 Jun 20 21:10:11 Creating backend connection for TCP % Jun 20 21:10:11 Backend launched with banner: OK Python backend ready. Jun 20 21:10:11 [bindbackend] Parsing 0 domain(s), will report when done Jun 20 21:10:11 [bindbackend] Done parsing domains, 0 rejected, 0 new, 0 removed Jun 20 21:10:11 About to create 3 backend threads for UDP Jun 20 21:10:11 Backend launched with banner: OK Python backend ready. Jun 20 21:10:11 Backend launched with banner: OK Python backend ready. Jun 20 21:10:11 Done launching threads, ready to distribute questions Jun 20 21:10:11 Backend launched with banner: OK Python backend ready.
Do some querys
user@pdnsdev:~$ dig example.org @127.0.0.1 SOA ; <<>> DiG 9.10.3-P4-Ubuntu <<>> example.org @127.0.0.1 SOA ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 63891 ;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1 ;; WARNING: recursion requested but not available ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 1680 ;; QUESTION SECTION: ;example.org. IN SOA ;; ANSWER SECTION: example.org. 300 IN SOA ns1.example.org. admin.example.org. 2018030311 86400 7200 3600000 3600 ;; Query time: 13 msec ;; SERVER: 127.0.0.1#53(127.0.0.1) ;; WHEN: Thu Jun 20 21:20:22 CEST 2018 ;; MSG SIZE rcvd: 86 user@pdnsdev:~$ dig www.example.org @127.0.0.1 ; <<>> DiG 9.10.3-P4-Ubuntu <<>> www.example.org @127.0.0.1 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 896 ;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1 ;; WARNING: recursion requested but not available ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 1680 ;; QUESTION SECTION: ;www.example.org. IN A ;; ANSWER SECTION: www.example.org. 300 IN A 1.1.1.1 ;; Query time: 26 msec ;; SERVER: 127.0.0.1#53(127.0.0.1) ;; WHEN: Thu Jun 20 21:20:44 CEST 2018 ;; MSG SIZE rcvd: 60
Have fun 🙂
