The Let's encrypt client certbot is installed according two methods:
- on regular servers, as a distro/OS package
- on Docker engines, as a container and a wrapper script
This change takes care of the second method.
The certbot/certbot image is used (previously, the letsencrypt
image on quay.org was used), as officially maintained by EFF.
A certbot wrapper command runs the container with the correct
volumes mounted to be able to generate or renew certificates.