#!/usr/bin/env python
"""
irker - a simple IRC multiplexer daemon
Takes JSON objects of the form {'channel':<channel-url>, 'privmsg':<text>}
and relays messages to IRC channels.
Run this as a daemon in order to maintain stateful connections to IRC
servers; this will allow it to respond to server pings and minimize
join/leave traffic.
Requires Python 2.6.
TO-DO: Is there any way to cope if servers drop connections?
TO-DO: Round-robin as in http://code.google.com/p/cia-vc/source/browse/trunk/cia/LibCIA/IRC/Network.py
TO-DO: Register the port?
"""
# These things might need tuning
HOST = "localhost"
PORT = 4747
TTL = (3 * 60 * 60) # Connection time to live in seconds
CONNECT_MAX = 18 # Maximum connections per bot (freenet limit)
NAMESTYLE = "irker%03d" # IRC nick template - must contain '%d'
# No user-serviceable parts below this line
import sys, json, exceptions, getopt, urlparse, time, socket
import threading, Queue, SocketServer
import irclib
class SessionException(exceptions.Exception):
def __init__(self, message):
exceptions.Exception.__init__(self)
self.message = message
class Session():
"IRC session and message queue processing."
def __init__(self, irker, url):
self.irker = irker
self.url = url
self.server = None
# Server connection setup
parsed = urlparse.urlparse(url)
host, _, port = parsed.netloc.partition(':')
if not port:
port = 6667
self.servername = host
self.channel = parsed.path.lstrip('/')
self.port = int(port)
# The consumer thread
self.queue = Queue.Queue()
self.thread = threading.Thread(target=self.dequeue)
self.thread.daemon = True
self.thread.start()
self.last_active = None
def enqueue(self, message):
"Enque a message for transmission."
self.queue.put(message)
def dequeue(self):
"Try to ship pending messages from the queue."
while True:
# We want to be kind to the IRC servers and not hold unused
# sockets open forever, so they have a time-to-live. The
# loop is coded this particular way so that we can drop
# the actual server connection when its time-to-live
# expires, then reconnect and resume transmission if the
# queue fills up again.
if not self.server:
self.server = self.irker.open(self.servername,
self.port)
self.irker.debug(1, "TTL bump (connection) at %s" % time.asctime())
self.last_active = time.time()
elif self.queue.empty():
if time.time() > self.last_active + TTL:
self.irker.debug(1, "timing out inactive connection at %s" % time.asctime())
self.irker.close(self.servername,
self.port)
self.server = None
break
else:
message = self.queue.get()
self.server.join("#" + self.channel)
self.server.privmsg("#" + self.channel, message)
self.last_active = time.time()
self.irker.debug(1, "TTL bump (transmission) at %s" % time.asctime())
self.queue.task_done()
def terminate(self):
"Terminate this session"
self.server.quit("#" + self.channel)
self.server.close()
def await(self):
"Block until processing of all queued messages is done."
self.queue.join()
class Irker:
"Persistent IRC multiplexer."
def __init__(self, debuglevel=0, namesuffix=None):
self.debuglevel = debuglevel
self.namesuffix = namesuffix or socket.getfqdn().replace(".", "-")
self.irc = irclib.IRC(debuglevel=self.debuglevel-1)
thread = threading.Thread(target=self.irc.process_forever)
self.irc._thread = thread
thread.daemon = True
thread.start()
self.sessions = {}
self.countmap = {}
self.servercount = 0
def logerr(self, errmsg):
"Log a processing error."
sys.stderr.write("irker: " + errmsg + "\n")
def debug(self, level, errmsg):
"Debugging information."
if self.debuglevel >= level:
sys.stderr.write("irker[%d]: %s\n" % (self.debuglevel, errmsg))
def nickname(self, n):
"Return a name for the nth server connection."
# The purpose of including the namme suffix (defaulting to the
# host's FQDN) is to ensure that the nicks of bots managed by
# instances running on different hosts can never collide.
return (NAMESTYLE % n) + "-" + self.namesuffix
def open(self, servername, port):
"Allocate a new server instance."
if not (servername, port) in self.countmap:
self.countmap[(servername, port)] = (CONNECT_MAX+1, None)
count = self.countmap[(servername, port)][0]
if count > CONNECT_MAX:
self.servercount += 1
newserver = self.irc.server()
newserver.connect(servername,
port,
self.nickname(self.servercount))
self.countmap[(servername, port)] = (1, newserver)
return self.countmap[(servername, port)][1]
def close(self, servername, port):
"Release a server instance and all sessions using it."
del self.countmap[(servername, port)]
for val in self.sessions.values():
if (val.servername, val.port) == (servername, port):
self.sessions[servername].terminate()
del self.sessions[servername]
def handle(self, line):
"Perform a JSON relay request."
try:
request = json.loads(line.strip())
if "channel" not in request or "privmsg" not in request:
self.logerr("ill-formed reqest")
else:
channel = request['channel']
message = request['privmsg']
if channel not in self.sessions:
self.sessions[channel] = Session(self, channel)
self.sessions[channel].enqueue(message)
except ValueError:
self.logerr("can't recognize JSON on input.")
def terminate(self):
"Ship all pending messages before terminating."
for session in self.sessions.values():
session.await()
class MyTCPHandler(SocketServer.StreamRequestHandler):
def handle(self):
while True:
irker.handle(self.rfile.readline().strip())
if __name__ == '__main__':
host = HOST
port = PORT
namesuffix = None
debuglevel = 0
(options, arguments) = getopt.getopt(sys.argv[1:], "d:p:n:")
for (opt, val) in options:
if opt == '-d':
debuglevel = int(val)
elif opt == '-p':
port = int(val)
elif opt == '-n':
namesuffix = val
irker = Irker(debuglevel=debuglevel, namesuffix=namesuffix)
server = SocketServer.TCPServer((host, port), MyTCPHandler)
try:
server.serve_forever()
except KeyboardInterrupt:
pass
# end