Python service discovery: Advertise a service across a local network

Question

I have a \"server\" python script running on one of the local network machines, which waits for clients to connect, and passes them some work to do. The server and client code h

Answer 1

An easy way to do service announcement/discovery on the local network is by broadcasting UDP packets.

Constants:

PORT = 50000
MAGIC = "fna349fn" #to make sure we don't confuse or get confused by other programs

Announcement:

from time import sleep
from socket import socket, AF_INET, SOCK_DGRAM, SOL_SOCKET, SO_BROADCAST, gethostbyname, gethostname

s = socket(AF_INET, SOCK_DGRAM) #create UDP socket
s.bind(('', 0))
s.setsockopt(SOL_SOCKET, SO_BROADCAST, 1) #this is a broadcast socket
my_ip= gethostbyname(gethostname()) #get our IP. Be careful if you have multiple network interfaces or IPs

while 1:
    data = MAGIC+my_ip
    s.sendto(data, ('<broadcast>', PORT))
    print "sent service announcement"
    sleep(5)

Discovery:

from socket import socket, AF_INET, SOCK_DGRAM

s = socket(AF_INET, SOCK_DGRAM) #create UDP socket
s.bind(('', PORT))

while 1:
    data, addr = s.recvfrom(1024) #wait for a packet
    if data.startswith(MAGIC):
        print "got service announcement from", data[len(MAGIC):]

This code was adapted from the demo on python.org