omprog-twisted-sample.py

omprog-twisted-sample.py

#!/usr/bin/env python

# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.

"""
Example using stdio, LineReceiver, ClientFactory and twisted.web.client.

This could be used with rsyslog omprog module to forward messages to 
 different servers

cat >> /etc/rsyslog.d/omprog-python.conf <<EOF
Module (load="omprog")
*.* action(type="omprog" 
           binary="/pathto/omprog-twisted-sample.py"
           template="RSYSLOG_TraditionalFileFormat")

EOF

Note that the WebCheckerCommandProtocol protocol could easily be used in e.g.
a telnet server instead; see the comments for details.

Based on an example by Abe Fettig.
"""

from twisted.internet import reactor, defer, endpoints
from twisted.internet import stdio, reactor, protocol
from twisted.protocols import basic
from twisted.web import client

class EchoClient(protocol.Protocol):
    """Once connected, send a message, then print the result."""

    def connectionMade(self):
        self.transport.write("Joining logserver")

    def dataReceived(self, data):
        "shouldn't receive data from server"
        pass

    def connectionLost(self, reason):
        print "connection lost"

    def sendMessage(self, msg):
        self.transport.write("MESSAGE %s\n" % msg)


class EchoFactory(protocol.ClientFactory):
    protocol = EchoClient

    def clientConnectionFailed(self, connector, reason):
        print "Connection failed - goodbye!"
        reactor.stop()

    def clientConnectionLost(self, connector, reason):
        print "Connection lost - goodbye!"
        reactor.stop()


class WebCheckerCommandProtocol(basic.LineReceiver):
    """Forwards received messages to a given server"""
    delimiter = '\n' # unix terminal style newlines. remove this line
                     # for use with Telnet

    def connectionMade(self):
        self.sendLine("Web checker console. Type 'help' for help.")

    def lineReceived(self, line):
        # Ignore blank lines
        if not line: return
        if not getattr(self,'connector',None):
            self.connector = reactor.connectTCP('127.0.0.1', 8000, EchoFactory())       

        self.sendLine('Sending line: ' + str(line))
        self.connector.transport.write(line + self.delimiter)
        print('%r' % 'done')

    def connectionLost(self, reason):
        # stop the reactor, only because this is meant to be run in Stdio.
        reactor.stop()

if __name__ == "__main__":
    stdio.StandardIO(WebCheckerCommandProtocol())
    reactor.run()