Sometimes when I run

pulumi up

it takes down all my cluster nodes and starts them again because of a new template body. Can I avoid this? This time I didn't even change anything related to the cluster

Maybe this has something to do with new kubernetes versions. Do you have enabled auto upgrade and configured a fixed version or maybe disabled auto upgrade and don't configured a fixed version so the nodes will be upgraded to the latest available version on pulumi up. I'm not sure if this could be the reason, it's just a wild guess.

I have the version fixed