How to Renew Let's Encrypt SSL Certificates on Ubuntu, Debian, and CentOS (Nginx & Apache Guide)

1. Test Renewal with Dry Run (Safe Simulation)

sudo certbot renew --dry-run

If all challenges succeed without error, your automated renewal pipeline is healthy.

2. Force Immediate Certificate Renewal

sudo certbot renew --force-renewal

3. Configure Automatic Web Server Reload (Deploy Hook)

# For Nginx:
sudo certbot renew --deploy-hook "systemctl reload nginx"

# For Apache:
sudo certbot renew --deploy-hook "systemctl reload apache2"

4. Verify Systemd Renewal Timer on Linux

sudo systemctl status certbot.timer