How to automatically renew Let’s Encrypt certbot certs on Ubuntu

On Ubuntu, you can easily setup a daily job that tries to renew almost-expired Let’s Encrypt certificates.

Create /etc/cron.daily/renewcerts:

#!/bin/bash
certbot renew
service nginx reload

After that, sudo chmod a+x /etc/cron.daily/renewcerts.

Now you should verify that the script would actually run:

run-parts --test -v /etc/cron.daily

should print, among other lines, this line:

/etc/cron.daily/renewcerts

IMPORTANT: You still need to run certbot renew manually every 1-2 months to check if there are any errors that might prevent certs from being renewed.

NOTE: Since the script is calling service nginx reload, you need to ensure that your nginx config files are not left in a broken state for too long if you edit them. Use sudo nginx -t to check for errors after you edit them. Also note that if you make nginx config changes, the script might unintentionally apply them to your productive HTTP/HTTPS server!