证书监控系统怎么创建

import requests
from datetime import datetime
import smtplib
from email.mime.text import MIMEText

def check_certificate(domain):
    try:
        cert = requests.get(f'https://{domain}', verify=True).raw.connection.sock.getpeercert()
        not_after = datetime.strptime(cert['notAfter'], '%b %d %H:%M:%S %Y GMT')
        return not_after
    except Exception as e:
        print(f"Error checking {domain}: {e}")
        return None

def send_email(domain, not_after):
    msg = MIMEText(f"The certificate for {domain} expires on {not_after}.")
    msg['Subject'] = 'Certificate Expiry Alert'
    msg['From'] = 'alert@example.com'
    msg['To'] = 'admin@example.com'

    with smtplib.SMTP('smtp.example.com') as server:
        server.send_message(msg)

domains = ['example.com', 'subdomain.example.com']

for domain in domains:
    expiry_date = check_certificate(domain)
    if expiry_date and (expiry_date - datetime.now()).days < 30:
        send_email(domain, expiry_date)