Is it possible to generate the certificate one machine and use it there for a while and to switch to a new machine with a different IP address later on (by changing the A-record for the domain name)?
Can I just copy the config files of letsencrypt to the new machine?
I ran this command:
certbot certonly --webroot -w /var/www/example -d example.com
Yes, the IP address used doesn’t matter to Let’s Encrypt. Just the hostname or hostnames. If those will be equal in the “new” situation, all should be fine.
Almost The machines are virtual machines which are generated automatically running the same operating system. But the specs are different. Some machines have more CPU power.