I have a working certificate for my machine and domains which successfully auto renews.
My VPS host wants to move me to a new node/machine due to problems on their side. I will be keeping my IP address and will be setting up as close to a clone of the current machine as possible.
What files/scripts should I copy and move to the new machine in order to have as seamless a transition as possible?
If you used Certbot, you should copy the entire /etc/letsencrypt directory and all its contents, making sure to use a method that preserves ownership, permissions and symbolic links - e.g. create a tar archive and extract it on the new server.
Make sure the version of Certbot you install on the new server is at least same version as on the old one (newer should be fine, older might not be). If you used certbot-auto, copy over the renewal cron job too. And of course you’ll also want to copy the configuration files for your web server.
If you used a different ACME client, let us know which one