How to assign IP address to interface in python?

Question

I have python script that set the IP4 address for my wireless and wired interfaces. So far, I use subprocess command like :

subprocess.call(["ip addr add local 192.168.1.2/24 broadcast 192.168.1.255 dev wlan0"])

How can I set the IP4 address of an interface using python libraries? and if there is any way to get an already existing IP configurations using python libraries ?

Answer 1

With pyroute2.IPRoute:

from pyroute2 import IPRoute
ip = IPRoute()
index = ip.link_lookup(ifname='em1')[0]
ip.addr('add', index, address='192.168.0.1', mask=24)
ip.close()

With pyroute2.IPDB:

from pyroute2 import IPDB
ip = IPDB()
with ip.interfaces.em1 as em1:
    em1.add_ip('192.168.0.1/24')
ip.release()

Answer 2

Set an address via the older ioctl interface:

import socket, struct, fcntl

SIOCSIFADDR = 0x8916
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)


def setIpAddr(iface, ip):
    bin_ip = socket.inet_aton(ip)
    ifreq = struct.pack('16sH2s4s8s', iface, socket.AF_INET, '\x00' * 2, bin_ip, '\x00' * 8)
    fcntl.ioctl(sock, SIOCSIFADDR, ifreq)


setIpAddr('em1', '192.168.0.1')

(setting the netmask is done with SIOCSIFNETMASK = 0x891C)

Ip addresses can be retrieved in the same way: Finding local IP addresses using Python's stdlib

I believe there is a python implementation of Netlink should you want to use that over ioctl