Author:Alexander
Zielenski (Google) Immutable fields can be found in a few
places in the built-in Kubernetes types.For example, you can't
change the .metadata.name of an object.Specific
objects have fields where changes to existing objects are
constrained;for example, the .spec.selector of a
Deployment. Aside from simple immutability, there are other common
design patterns such as lists which are append-only, or a map with
mutable values and immutable keys. Until recently the best way to
restrict field mutability for CustomResourceDefinitions has been to