Small python script that connects one or more TCP servers to each other.

server2server.py

#!/usr/bin/env python

import sys
import socket
import select

def usage(name):
  print('Usage {} [hostname:port](2..n)'.format(name))

if (len(sys.argv) < 3):
  usage(sys.argv[0])
  sys.exit(1)

connections = []
for endpoint in sys.argv[1:]:
  hostname, port = endpoint.split(':')

  s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
  s.connect((hostname, int(port)))
  connections.append(s)

  print("Connected to {}".format(endpoint))

fd_set = set([ c.fileno() for c in connections ])
fd_map = { c.fileno(): c for c in connections }

while True:
  r, w, x = select.select(fd_set, [], [])

  for fd in r:
    data = fd_map[fd].recv(4096)
    if not len(data):
      sys.exit(0)

    for c in connections:
      if c.fileno() == fd:
        continue
      c.sendall(data)