Cert Expiry Bot is a Bash script that monitors SSL certificates for multiple domains and sends notifications if they are expiring soon. It checks for expirations within 14 and 7 days (configurable), and includes error handling for invalid domains or missing certificates.

• Monitors SSL certificates for multiple domains.
• Sends notifications for certificates expiring within configurable thresholds.
• Supports multiple notification methods:
  • ntfy
  • Telegram Bot
  • Webhook
• Includes error handling for invalid domains or missing certificates.
• Easy configuration via .env and .conf files.

• curl and openssl must be installed.
• At least one notification method must be configured in .env.

1. Configure environment:

   • Copy .env.example to .env:

     cp .env.example .env

   • Edit .env and set one or more of the following:

     # ntfy
     NTFY_TOPIC=server-topic-123
     
     # Telegram
     TELEGRAM_BOT_TOKEN=1234567890:ABC
     TELEGRAM_CHAT_ID=9876543210
     
     # Webhook
     WEBHOOK_URL=https://webhook.domain.com/endpoint

   • Secure the file:

     chmod 600 .env

2. Add domains to monitor:

   • Copy cert_expiry_bot.txt.example to cert_expiry_bot.txt:

     cp cert_expiry_bot.txt.example cert_expiry_bot.txt

   • Edit cert_expiry_bot.txt and add one domain per line (e.g., domain1.com).

3. Configure thresholds:

   • Edit cert_expiry_bot.conf and adjust if needed, or leave default values:

     EXPIRATION_TIME_SHORT=7
     EXPIRATION_TIME_LONG=14

4. Make the script executable:

   chmod +x cert_expiry_bot.sh

5. Test the script:

   • To test, set EXPIRATION_TIME_LONG to 90 in cert_expiry_bot.conf (since domains typically renew 30 days before expiry, this will likely trigger alerts for most domains).

   • Run the script manually:

     ./cert_expiry_bot.sh

6. Schedule a cron job:

   • Edit your crontab:

     crontab -e

   • Add this line to run every day at 12:00:

     0 12 * * * /path/to/cert_expiry_bot.sh

• The script uses openssl to check SSL certificates, so the domains must be accessible over HTTPS on port 443.

Paul Sørensen
https://paulsorensen.io
https://github.com/paulsorensen

If you found this project useful, a small tip is appreciated ❤️
https://buymeacoffee.com/paulsorensen

This project is licensed under the MIT License.
See LICENSE for details.