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mirror of https://github.com/balkian/gists.git synced 2024-11-21 17:22:29 +00:00
This commit is contained in:
J. Fernando Sánchez 2015-10-20 12:44:55 +02:00
commit 9b0dc3f613

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dns.py Normal file
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# -*- coding: utf-8 -*-
from __future__ import print_function
try:
from subprocess import getoutput
except ImportError:
from commands import getoutput
from dnslib import RR,QTYPE,RCODE,A,parse_time
from dnslib.label import DNSLabel
from dnslib.server import DNSServer,DNSHandler,BaseResolver,DNSLogger
from docker import Client, errors
class DockerResolver(BaseResolver):
"""
"""
def __init__(self, docker='unix://var/run/docker.sock',
origin='docker', ttl='60s'):
self.client = Client(base_url=docker)
self.origin = DNSLabel(origin)
self.ttl = parse_time(ttl)
def resolve(self,request,handler):
reply = request.reply()
qname = request.q.qname
print("Queried: %s" % qname)
print("Label: %s" % self.origin)
found = False
if not qname.matchSuffix(self.origin):
print("Not the %s domain" % self.origin)
return reply
cname = "/" + str(qname.stripSuffix(self.origin))[:-1].replace("/", "_")
try:
for c in self.client.containers():
if cname in c["Names"]:
container = self.client.inspect_container(c["Id"])
ns = container.get("NetworkSettings", {})
if ns:
address = ns.get("IPAddress", None)
print("Found %s [%s]" % (cname, address))
if address:
reply.add_answer(RR(qname,QTYPE.A,ttl=self.ttl,
rdata=A(address)))
else:
print("Found %s - NO IP" % cname)
found = True
break
if not found:
print("Container not found: %s" % cname)
except Exception as ex:
print("Error occurred querying [%s]: %s" % (cname, ex))
return reply
if __name__ == '__main__':
import argparse,sys,time
p = argparse.ArgumentParser(description="Docker DNS Resolver")
p.add_argument("--docker","-d",default="unix://var/run/docker.sock",
metavar="<url>",
help="Docker Socket/URL (default: unix://var/run/docker.sock)")
p.add_argument("--origin","-o",default="docker",
metavar="<origin>",
help="Origin domain label (default: .)")
p.add_argument("--ttl","-t",default="60s",
metavar="<ttl>",
help="Response TTL (default: 60s)")
p.add_argument("--port","-p",type=int,default=53,
metavar="<port>",
help="Server port (default:53)")
p.add_argument("--address","-a",default="",
metavar="<address>",
help="Listen address (default:all)")
p.add_argument("--udplen","-u",type=int,default=0,
metavar="<udplen>",
help="Max UDP packet length (default:0)")
p.add_argument("--tcp",action='store_true',default=False,
help="TCP server (default: UDP only)")
p.add_argument("--log",default="request,reply,truncated,error",
help="Log hooks to enable (default: +request,+reply,+truncated,+error,-recv,-send,-data)")
p.add_argument("--log-prefix",action='store_true',default=False,
help="Log prefix (timestamp/handler/resolver) (default: False)")
args = p.parse_args()
resolver = DockerResolver(docker=args.docker, origin=args.origin, ttl=args.ttl)
logger = DNSLogger(args.log,args.log_prefix)
print("Starting Docker Resolver for %s (%s:%d) [%s]" % (
args.docker,
args.address or "*",
args.port,
"UDP/TCP" if args.tcp else "UDP"))
if args.udplen:
DNSHandler.udplen = args.udplen
udp_server = DNSServer(resolver,
port=args.port,
address=args.address,
logger=logger)
udp_server.start_thread()
if args.tcp:
tcp_server = DNSServer(resolver,
port=args.port,
address=args.address,
tcp=True,
logger=logger)
tcp_server.start_thread()
while udp_server.isAlive():
time.sleep(1)