script ran on pfsense router and alert on slack using web-hook when a new IP address is registered

SP_Notify.py

import requests, json, subprocess, os

web_hook = ""
filepath = "/tmp/addresses"

def msg_sender(hostname, macaddress, ipaddress):
    slack_data = {
        "text": "Text.",
        "blocks": [
    	{
			"type": "section",
			"text": {
				"type": "mrkdwn",
				"text": "Hostname: `" + hostname + "` \nMac Address: `" + macaddress + "` \nIP Address: `" + ipaddress + "` "
			}
		}
    ]
    }

    response = requests.post(web_hook, data=json.dumps(
    slack_data), headers={'Content-Type': 'application/json'})
    if response.status_code != 200:
        raise ValueError(
        'Request to slack returned an error %s, the response is:\n%s'
        % (response.status_code, response.text))


def cmd_runner(command):
 
    process = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    output, error = process.communicate()
    if error:
        return None
    return output.decode()



def file_writer(macaddress):
   
    file_object = open(filepath, 'a')
    for mac in macaddress:
        if not check_address(macaddress):
            file_object.write(mac)
            file_object.write("\n")
        
def check_address(macaddress):
    fileExist = os.path.exists(filepath)
    if not fileExist:
        f = open(filepath,"w+")
    file_object = open(filepath, 'r')
    flines = file_object.readlines()
    flines = [i.strip("\n") for i in flines]
    if macaddress in flines:
        return True
    return False

def arp_reader():
    mac_addresses_lst = []
    Hostnames = "arp -a | awk '{print $1}'"
    macaddress = "arp -a | awk '{print $4}'"
    IPAdress = "arp -a | awk '{print $2}'"

    Hostnames = cmd_runner(Hostnames).strip().split('\n')
    macaddress = cmd_runner(macaddress).strip().split('\n')
    IPAdress = cmd_runner(IPAdress).strip().split('\n')
    
    length = len(IPAdress)

    for record in range(0, length):
        mac_addresses_lst.append(macaddress[record])
        if Hostnames[record] == "?":
            Hostnames[record] = "None"
        if not check_address(macaddress[record]):
            msg_sender(Hostnames[record],macaddress[record], IPAdress[record])
    return mac_addresses_lst


def worker():
    
    mac_address_lst = arp_reader()

    file_writer(mac_address_lst)

    


def main():
    worker()

if __name__ == "__main__": 
    main()

This is useful. Thank you for sharing.