detectIPchange.py

#!/usr/bin/python
import sys
import requests
import json
import subprocess

def evaluate_ips():
     r = requests.get('http://ipinfo.io')
     current_ip = json.loads(r.text)['ip']
     f = open('/root/last_ip.txt', 'r+')
     last_ip = f.read().strip()
     f.seek(0)
     f.write(current_ip + '\n')
     f.truncate()
     f.close()
     if current_ip != last_ip:
         compose_email( current_ip, last_ip )
         send_email()

def compose_email( current, last ):
     with open('/root/mail.txt', 'w') as f:
          f.write('From: "alarmpi" <alarm3dot14[AT]gmail.com>\n')
          f.write('To: "Caleb Sabatini" <calebsabatini[AT]gmail.com>\n')
          f.write('Subject: Public IP change detected\n\n')
          f.write('Detected by raspberry pi on LAN\n')
          f.write('Last IP: ' + last + '\nCurrent IP: ' + current + '\n')

def send_email():
     bashCmd = """curl --url smtps://smtp.gmail.com:465 --ssl-reqd \
        --mail-from "alarm3dot14[AT]gmail.com" --mail-rcpt "calebsabatini[AT]gmail.com" \
        --upload-file /root/mail.txt --user "user:pass" --insecure"""
     subprocess.call(bashCmd, shell=True)

evaluate_ips()