Check certificate expiry using Python

 Following python script can use to check HTTPS certifcate expiry.

import ssl
import socket
import requests
from datetime import datetime

# Configuration
HOST = "mobitel.lk"  # Change to your domain
PORT = 443
THRESHOLD_DAYS = 30  # Alert before expiry (days)
API_URL = "https://your-api.com/alert"  # REST API to notify

def get_ssl_expiry(host, port):
    context = ssl.create_default_context()
    with socket.create_connection((host, port)) as sock:
        with context.wrap_socket(sock, server_hostname=host) as ssock:
            cert = ssock.getpeercert()
            expiry_date = datetime.strptime(cert['notAfter'], "%b %d %H:%M:%S %Y %Z")
            return expiry_date

def send_alert():
    data = {"message": f"SSL certificate for {HOST} is expiring soon!"}
    response = requests.post(API_URL, json=data)
    print(f"Alert sent: {response.status_code}")
# Check expiry

expiry_date = get_ssl_expiry(HOST, PORT)
days_left = (expiry_date - datetime.now()).days
if days_left <= THRESHOLD_DAYS:
    send_alert()
    print(f"Certificate expiring in {days_left} days. Alert sent!")
else:
    print(f"Certificate is valid for {days_left} more days.")