k8s - kuberctl create/replace/apply/patch?

From:  stackoverflow

My original was rather controversial and I would even say now, in hindsight, half incorrect. So here is an updated answer which I hope will be more helpful:

• commands like kubectl patch, replace, delete, create, even edit are all imperative: they tell kubectl exactly what to do

• the kubectl apply command is OTOH "declarative" in that it tells kubernetes, here is a desired state (the yaml from the file provided to the apply command), now figure out how to get there: create, patch, replace the object, etc whatever it takes... you get the idea.

So the 2 commands are hugely different.

EG with apply you can give it just the changes you want: it will figure out what properties of the object need to be changed, and leave the other ones alone; if those properties are "immutable" (eg, the nodeName of a pod), it will complain, and if you then repeat the command with --force, it is smart enough to know to do the equivalent of a replace --force.

In general, you should favor apply (with --force when necessary), and only use the imperative commands when the declarative approach does not give the expected result (although I would love to see examples of this -- I'm guessing this would happen only when you would need several steps because of interdependencies that will have negative consequences if done with apply).