Certbot

certbot is a fully-featured, extensible client for the Let’s Encrypt CA (or any other CA that speaks the ACME protocol) that can automate the tasks of obtaining certificates and configuring webservers to use them. This client runs on Unix-based operating systems.

Ubuntu:

• Binaries: cerbot and letscrypt
• Renewals: /etc/cron.d/certbot

certonly --standalone

certbot --nginx
Saving debug log to /var/log/letsencrypt/letsencrypt.log
The requested nginx plugin does not appear to be installed

certbot certificates
Saving debug log to /var/log/letsencrypt/letsencrypt.log

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
No certs found.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

certbot renew
Saving debug log to /var/log/letsencrypt/letsencrypt.log

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

No renewals were attempted.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

• Changing a Certificdate's Domain: certbot certonly --cert-name example.com -d example.org,www.example.org
• Automated renewals: systemctl list-timers

See also

• HTTP, HTTP client, HTTP/1.1, HTTP/2, HTTP/3, HTTPS, HSTS CSR, TLS, SSL, openSSL, WebSockets, WebRTC, ssl_certificate QUIC, HPKP, CT, List of HTTP status codes, URL redirection, Content-type:, Webhook, HTTP headers, --insecure, Axios HTTP client, HTTP cookies, HTTP ETag, Hypertext Transfer Protocol -- HTTP/1.1

https://certbot.eff.org/docs/intro.html

https://certbot.eff.org/docs/using.html#changing-a-certificate-s-domains