Ubuntu 26.04 LTS
sudo apt update && sudo apt upgrade
sudo apt install certbot python3-certbot-nginx
sudo certbot --nginx -d dixu.ddns.net
sudo certbot renew --dry-run
curl -I http://dixu.ddns.net
systemctl status certbot.timer
systemctl list-timers | grep certbot
sudo certbot certificates
sudo certbot delete --cert-name dixu.ddns.net
sudo systemctl disable --now certbot.timer
Ubuntu 24.04 LTS
sudo apt update && sudo apt upgrade
sudo apt install python3-certbot-nginx # For Nginx
sudo apt install python3-certbot-apache # For Apache
Request a new Let’s Encrypt SSL certificate and install the certificate.
sudo certbot --nginx -d www.example.com
Verify that Certbot auto-renews the SSL certificate upon expiry.
sudo certbot renew --dry-run
sudo certbot certificates
sudo certbot delete --cert-name www.example.com
CentOS 7 & 8
sudo yum install epel-release
sudo yum install certbot python3-certbot-nginx # For Nginx
sudo yum install certbot python3-certbot-apache # For Apache
Automatically Obtain and Install Certificates
sudo certbot --nginx
sudo certbot --apache
Using Standalone Mode to Generate Certificates
sudo systemctl stop nginx
sudo certbot certonly --standalone -d example.com -d www.example.com
sudo systemctl start nginx
Obtain a certificate by writing to the Webroot directory of a running Web server.
certbot certonly --webroot -w /var/www/example -d www.example.com
Test Certificate Renewal Process
sudo certbot renew --dry-run
Manual renewal of certificates
sudo certbot renew
Notes
Port 80 needs to be reachable from the internet for the http-01 challenge, not just port 443.