NewInstallerController creates a new installer controller.

Int32KeySet creates a Int32 from a keys of a map[int32](? extends interface{}).

NewInt32 creates a Int32 from a list of values.

InstallerController is a controller that watches the currentRevision and targetRevision fields for each node and spawn installer pods to update the static pods on the master nodes.

InstallerPodMutationFunc is a function that has a chance at changing the installer pod before it is created.

sets.Int32 is a set of int32s, implemented via map[int32]struct{} for minimal memory consumption.