NetAlertX/front/plugins/internet_ip/script.py

#!/usr/bin/env python

import os
import time
import argparse
import sys
import subprocess
import re

# Register NetAlertX directories
INSTALL_PATH = os.getenv('NETALERTX_APP', '/app')
sys.path.extend([f"{INSTALL_PATH}/front/plugins", f"{INSTALL_PATH}/server"])

from plugin_helper import Plugin_Objects
from logger import mylog, Logger, append_line_to_file
from helper import timeNowTZ, check_IP_format, get_setting_value
from const import logPath
import conf
from pytz import timezone

# Make sure the TIMEZONE for logging is correct
conf.tz = timezone(get_setting_value('TIMEZONE'))

# Make sure log level is initialized correctly
Logger(get_setting_value('LOG_LEVEL'))

pluginName = 'INTRNT'

LOG_PATH = logPath + '/plugins'
LOG_FILE = os.path.join(LOG_PATH, f'script.{pluginName}.log')
RESULT_FILE = os.path.join(LOG_PATH, f'last_result.{pluginName}.log')


no_internet_ip = '0.0.0.0'

def main():

    mylog('verbose', [f'[{pluginName}] In script'])     
    
    parser = argparse.ArgumentParser(description='Check internet connectivity and IP')
    
    parser.add_argument('prev_ip', action="store", help="Previous IP address to compare against the current IP")
    parser.add_argument('DIG_GET_IP_ARG', action="store", help="Arguments for the 'dig' command to retrieve the IP address") # unused

    values = parser.parse_args()

    PREV_IP         = values.prev_ip.split('=')[1]        
    DIG_GET_IP_ARG  = get_setting_value("INTRNT_DIG_GET_IP_ARG")

    new_internet_IP = no_internet_ip

    mylog('verbose', [f'[{pluginName}] INTRNT_DIG_GET_IP_ARG: ', DIG_GET_IP_ARG])     

    # METHOD 1: dig
    # perform the new IP lookup N times specified by the INTRNT_TRIES setting
    
    INTRNT_RETRIES  = get_setting_value("INTRNT_RETRIES")
    retries_needed  = 0

    for i in range(INTRNT_RETRIES + 1):

        new_internet_IP, cmd_output = check_internet_IP( PREV_IP, DIG_GET_IP_ARG)   

        if new_internet_IP == no_internet_ip:
            time.sleep(1*i) # Exponential backoff strategy
        else:
            retries_needed = i
            break

    # METHOD 2: curl
    if new_internet_IP == no_internet_ip:
        new_internet_IP, cmd_output = fallback_check_ip()
        mylog('verbose', [f'[{pluginName}] Curl Fallback (new_internet_IP|cmd_output): {new_internet_IP} | {cmd_output}'])   

    #  logging
    append_line_to_file (logPath + '/IP_changes.log', '['+str(timeNowTZ()) +']\t'+ new_internet_IP +'\n')    

    plugin_objects = Plugin_Objects(RESULT_FILE)    
    
    plugin_objects.add_object(
        primaryId   = 'Internet',       # MAC (Device Name)
        secondaryId = new_internet_IP,  # IP Address 
        watched1    = f'Previous IP: {PREV_IP}',
        watched2    = cmd_output.replace('\n',''),
        watched3    = retries_needed,  
        watched4    = 'Gateway',
        extra       = f'Previous IP: {PREV_IP}', 
        foreignKey  = 'Internet')

    plugin_objects.write_result_file() 

    mylog('verbose', [f'[{pluginName}] Finished '])   
    
    return 0
  
    
#===============================================================================
# INTERNET IP CHANGE
#===============================================================================
def check_internet_IP ( PREV_IP, DIG_GET_IP_ARG ):   
    
    # Get Internet IP
    mylog('verbose', [f'[{pluginName}] - Retrieving Internet IP'])
    internet_IP, cmd_output = get_internet_IP(DIG_GET_IP_ARG)

    mylog('verbose', [f'[{pluginName}]  Current internet_IP : {internet_IP}'])        
    
    # Check previously stored IP    
    previous_IP = no_internet_ip

    if  PREV_IP is not None and len(PREV_IP) > 0 :
        previous_IP = PREV_IP

    mylog('verbose', [f'[{pluginName}]          previous_IP : {previous_IP}']) 

    return internet_IP, cmd_output
    

#-------------------------------------------------------------------------------
def get_internet_IP (DIG_GET_IP_ARG):

    cmd_output = ''
    
    # Using 'dig'
    dig_args = ['dig', '+short'] + DIG_GET_IP_ARG.strip().split()
    try:
        cmd_output = subprocess.check_output (dig_args, universal_newlines=True)
        mylog('verbose', [f'[{pluginName}]  DIG result : {cmd_output}'])    
    except subprocess.CalledProcessError as e:
        mylog('verbose', [e.output])
        cmd_output = '' # no internet

    # Check result is an IP
    IP = check_IP_format (cmd_output)

    # Handle invalid response
    if IP == '':
        IP = no_internet_ip

    return IP, cmd_output

#-------------------------------------------------------------------------------
def fallback_check_ip():
    """Fallback mechanism using `curl ifconfig.me/ip`."""
    try:
        cmd_output = subprocess.check_output(['curl', '-s', 'ifconfig.me/ip'], text=True).strip()
        if cmd_output and re.match(r"^\d{1,3}(\.\d{1,3}){3}$", cmd_output):
            mylog('verbose', [f'[{pluginName}] Fallback IP retrieved via curl: {cmd_output}'])
            return cmd_output, f'Fallback via curl: "{cmd_output}"'
        else:
            mylog('verbose', [f'[{pluginName}] Invalid IP received from fallback'])
            return no_internet_ip, f'Fallback via curl failed: "{cmd_output}"'
    except Exception as e:
        mylog('none', [f'[{pluginName}] Fallback curl exception: {e}'])
        return no_internet_ip, f'Fallback via curl exception: "{e}"'

#===============================================================================
# BEGIN
#===============================================================================
if __name__ == '__main__':
    main()