kubernetes/pkg/controlplane/controller/systemnamespaces/system_namespaces_controller.go

type Controller …

// NewController creates a new Controller to ensure system namespaces exist.
func NewController(systemNamespaces []string, clientset kubernetes.Interface, namespaceInformer coreinformers.NamespaceInformer) *Controller { … }

// Run starts one worker.
func (c *Controller) Run(stopCh <-chan struct{ … }

func (c *Controller) sync() { … }

func (c *Controller) createNamespaceIfNeeded(ns string) error { … }