ipnotify.py

# Raspberry Pi Pushover IP Notifier
# by Matt Harzewski (2021)
# License: MIT
# 
# On system boot, this script checks to see if
# the IP address has changed, and sends a
# Pushover notification if it is different.
#
# Set the user and application tokens with your
# own from Pushover.net, and add the script to
# the crontab: @reboot python3 path/to/ipnotify.py

from urllib import request, parse
from datetime import datetime, date
import socket, os.path, subprocess

def push(title, msg):
    params = {
        "token": "PUSHOVER_APP_TOKEN",
        "user": "PUSHOVER_USER_TOKEN",
        "title": title,
        "message": msg
    }
    req = request.Request(
        "https://api.pushover.net/1/messages.json",
        data=parse.urlencode(params).encode()
    )
    res = request.urlopen(req)

def getIp():
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    ip = None
    try:
        sock.connect(('8.8.8.8', 1))
        ip = sock.getsockname()[0]
    except Exception:
        sock.close()
    sock.close()
    return ip

def storeIp(ip):
    with open(os.path.expanduser('~/.ipnotify'), "w+") as f:
        f.write(f"{ip}|{getUptime()}")

def getStoredIp():
    ip = None
    when = None
    with open(os.path.expanduser('~/.ipnotify'), "r") as f:
        data = f.read()
        data = data.split('|')
        ip = data[0]
        when = data[1]
    return ip, when

def getUptime():
    return subprocess.getoutput('uptime -s')

if __name__ == '__main__':
    current = getIp();
    today = datetime.combine(date.today(), datetime.min.time())
    if os.path.exists(os.path.expanduser('~/.ipnotify')):
        prev, when = getStoredIp()
        dt = datetime.strptime(when.strip(), "%Y-%m-%d %H:%M:%S")
        if current != prev or dt < today:
            push("Current IP", current)
    storeIp(current)