network_delay.py

#!/usr/bin/env python26

# Script for adding artificial delay to mysql using unix sockets
# Adds another socket and effectively man-in-the-middles the connection

# To use, change the settings on the application to point the database to
# to the temporary socket location, then run network_delay.py, then start
# the application

import os, os.path
import signal
import socket
import stat
import sys
from threading import Thread, Lock
import time

class Forwarder(Thread):
    def __init__(self, sockin, sockout):
        Thread.__init__(self)
        self.sockin = sockin
        self.sockout = sockout

    def run(self):
        while True:
            data = self.sockin.recv(4096)
            try:
                time.sleep(0.1)
                self.sockout.sendall(data)
            except:
                pass

mysql_sockfile = # mysql socket location here
proxy_sockfile = # temp socket location here

def signal_handler(signal, frame):
    print "-" * 20
    print "Shutting down..."

    mysql_server.close()
    proxy_server.close()
    os.remove( proxy_sockfile )

    print "Done"
    sys.exit(0)

signal.signal(signal.SIGINT, signal_handler)

if os.path.exists( proxy_sockfile ):
  os.remove( proxy_sockfile )

print "Opening socket..."

proxy_server = socket.socket( socket.AF_UNIX, socket.SOCK_STREAM )
proxy_server.bind(proxy_sockfile)
proxy_server.listen(5)
os.chmod(proxy_sockfile, os.stat(proxy_sockfile).st_mode | stat.S_IWOTH)

print "Listening..."
while True:
    conn, addr = proxy_server.accept()
    mysql_server = socket.socket( socket.AF_UNIX, socket.SOCK_STREAM )
    mysql_server.connect(mysql_sockfile)

    print 'accepted connection'

    f1 = Forwarder(conn, mysql_server)
    f2 = Forwarder(mysql_server, conn)
    f1.start()
    f2.start()