drain

README

Drain code

This is the drain code copied from k8s.io/kubernetes, after the extraction in https://github.com/kubernetes/kubernetes/pull/80045/files

Once we are on that version of k/k (1.16), we can replace with the upstream version.

Documentation

Index

• Constants
• func CheckEvictionSupport(clientset kubernetes.Interface) (string, error)
• func RunCordonOrUncordon(drainer *Helper, node *corev1.Node, desired bool) error
• func RunNodeDrain(drainer *Helper, nodeName string) error
• type CordonHelper
  • func NewCordonHelper(node *corev1.Node) *CordonHelper
  • func NewCordonHelperFromRuntimeObject(nodeObject runtime.Object, scheme *runtime.Scheme, gvk schema.GroupVersionKind) (*CordonHelper, error)
  • func (c *CordonHelper) PatchOrReplace(clientset kubernetes.Interface) (error, error)
  • func (c *CordonHelper) UpdateIfRequired(desired bool) bool
• type Helper
  • func (d *Helper) DeleteOrEvictPods(pods []corev1.Pod) error
  • func (d *Helper) DeletePod(pod corev1.Pod) error
  • func (d *Helper) EvictPod(pod corev1.Pod, policyGroupVersion string) error
  • func (d *Helper) GetPodsForDeletion(nodeName string) (*podDeleteList, []error)

Constants

const (
	// EvictionKind represents the kind of evictions object
	EvictionKind = "Eviction"
	// EvictionSubresource represents the kind of evictions object as pod's subresource
	EvictionSubresource = "pods/eviction"
)

Functions

func CheckEvictionSupport

func CheckEvictionSupport(clientset kubernetes.Interface) (string, error)

CheckEvictionSupport uses Discovery API to find out if the server support eviction subresource If support, it will return its groupVersion; Otherwise, it will return an empty string

func RunCordonOrUncordon

func RunCordonOrUncordon(drainer *Helper, node *corev1.Node, desired bool) error

RunCordonOrUncordon demonstrates the canonical way to cordon or uncordon a Node

func RunNodeDrain

func RunNodeDrain(drainer *Helper, nodeName string) error

RunNodeDrain shows the canonical way to drain a node. You should first cordon the node, e.g. using RunCordonOrUncordon

Types

type CordonHelper

type CordonHelper struct {
	// contains filtered or unexported fields
}

CordonHelper wraps functionality to cordon/uncordon nodes

func NewCordonHelper

func NewCordonHelper(node *corev1.Node) *CordonHelper

NewCordonHelper returns a new CordonHelper

func NewCordonHelperFromRuntimeObject

func NewCordonHelperFromRuntimeObject(nodeObject runtime.Object, scheme *runtime.Scheme, gvk schema.GroupVersionKind) (*CordonHelper, error)

NewCordonHelperFromRuntimeObject returns a new CordonHelper, or an error if given object is not a node or cannot be encoded as JSON

func (*CordonHelper) PatchOrReplace

func (c *CordonHelper) PatchOrReplace(clientset kubernetes.Interface) (error, error)

PatchOrReplace uses given clientset to update the node status, either by patching or updating the given node object; it may return error if the object cannot be encoded as JSON, or if either patch or update calls fail; it will also return a second error whenever creating a patch has failed

func (*CordonHelper) UpdateIfRequired

func (c *CordonHelper) UpdateIfRequired(desired bool) bool

UpdateIfRequired returns true if c.node.Spec.Unschedulable isn't already set, or false when no change is needed

type Helper

type Helper struct {
	Client              kubernetes.Interface
	Force               bool
	GracePeriodSeconds  int
	IgnoreAllDaemonSets bool
	Timeout             time.Duration
	DeleteLocalData     bool
	Selector            string
	PodSelector         string
	Out                 io.Writer
	ErrOut              io.Writer

	// TODO(justinsb): unnecessary?
	DryRun bool

	// OnPodDeletedOrEvicted is called when a pod is evicted/deleted; for printing progress output
	OnPodDeletedOrEvicted func(pod *corev1.Pod, usingEviction bool)
}

Helper contains the parameters to control the behaviour of drainer

func (*Helper) DeleteOrEvictPods

func (d *Helper) DeleteOrEvictPods(pods []corev1.Pod) error

DeleteOrEvictPods deletes or evicts the pods on the api server

func (*Helper) DeletePod

func (d *Helper) DeletePod(pod corev1.Pod) error

DeletePod will delete the given pod, or return an error if it couldn't

func (*Helper) EvictPod

func (d *Helper) EvictPod(pod corev1.Pod, policyGroupVersion string) error

EvictPod will evict the give pod, or return an error if it couldn't

func (*Helper) GetPodsForDeletion

func (d *Helper) GetPodsForDeletion(nodeName string) (*podDeleteList, []error)

GetPodsForDeletion receives resource info for a node, and returns those pods as PodDeleteList, or error if it cannot list pods. All pods that are ready to be deleted can be obtained with .Pods(), and string with all warning can be obtained with .Warnings(), and .Errors() for all errors that occurred during deletion.