controllerutil

Documentation

Overview

Package controllerutil contains utility functions for working with and implementing Controllers.

Index

• func AddFinalizer(o metav1.Object, finalizer string)
• func AddFinalizerWithError(o runtime.Object, finalizer string) error
• func ContainsFinalizer(o Object, finalizer string) bool
• func RemoveFinalizer(o metav1.Object, finalizer string)
• func RemoveFinalizerWithError(o runtime.Object, finalizer string) error
• func SetControllerReference(owner, controlled metav1.Object, scheme *runtime.Scheme) error
• func SetOwnerReference(owner, object metav1.Object, scheme *runtime.Scheme) error
• type AlreadyOwnedError
  • func (e *AlreadyOwnedError) Error() string
• type MutateFn
• type Object
• type OperationResult
  • func CreateOrUpdate(ctx context.Context, c client.Client, obj runtime.Object, f MutateFn) (OperationResult, error)

Examples

• CreateOrUpdate

Functions

func AddFinalizer

func AddFinalizer(o metav1.Object, finalizer string)

AddFinalizer accepts a metav1 object and adds the provided finalizer if not present.

func AddFinalizerWithError

func AddFinalizerWithError(o runtime.Object, finalizer string) error

AddFinalizerWithError tries to convert a runtime object to a metav1 object and add the provided finalizer. It returns an error if the provided object cannot provide an accessor.

func ContainsFinalizer

func ContainsFinalizer(o Object, finalizer string) bool

ContainsFinalizer checks a metav1 object that the provided finalizer is present.

func RemoveFinalizer

func RemoveFinalizer(o metav1.Object, finalizer string)

RemoveFinalizer accepts a metav1 object and removes the provided finalizer if present.

func RemoveFinalizerWithError

func RemoveFinalizerWithError(o runtime.Object, finalizer string) error

RemoveFinalizerWithError tries to convert a runtime object to a metav1 object and remove the provided finalizer. It returns an error if the provided object cannot provide an accessor.

func SetControllerReference

func SetControllerReference(owner, controlled metav1.Object, scheme *runtime.Scheme) error

SetControllerReference sets owner as a Controller OwnerReference on controlled. This is used for garbage collection of the controlled object and for reconciling the owner object on changes to controlled (with a Watch + EnqueueRequestForOwner). Since only one OwnerReference can be a controller, it returns an error if there is another OwnerReference with Controller flag set.

func SetOwnerReference

func SetOwnerReference(owner, object metav1.Object, scheme *runtime.Scheme) error

SetOwnerReference is a helper method to make sure the given object contains an object reference to the object provided. This allows you to declare that owner has a dependency on the object without specifying it as a controller. If a reference to the same object already exists, it'll be overwritten with the newly provided version.

Types

type AlreadyOwnedError

type AlreadyOwnedError struct {
	Object metav1.Object
	Owner  metav1.OwnerReference
}

AlreadyOwnedError is an error returned if the object you are trying to assign a controller reference is already owned by another controller Object is the subject and Owner is the reference for the current owner

func (*AlreadyOwnedError) Error

func (e *AlreadyOwnedError) Error() string

type MutateFn

type MutateFn func() error

MutateFn is a function which mutates the existing object into it's desired state.

type Object

type Object interface {
	metav1.Object
	runtime.Object
}

Object allows functions to work indistinctly with any resource that implements both Object interfaces.

type OperationResult

type OperationResult string

OperationResult is the action result of a CreateOrUpdate call

const (
	// OperationResultNone means that the resource has not been changed
	OperationResultNone OperationResult = "unchanged"
	// OperationResultCreated means that a new resource is created
	OperationResultCreated OperationResult = "created"
	// OperationResultUpdated means that an existing resource is updated
	OperationResultUpdated OperationResult = "updated"
)

func CreateOrUpdate

func CreateOrUpdate(ctx context.Context, c client.Client, obj runtime.Object, f MutateFn) (OperationResult, error)

CreateOrUpdate creates or updates the given object in the Kubernetes cluster. The object's desired state must be reconciled with the existing state inside the passed in callback MutateFn.

The MutateFn is called regardless of creating or updating an object.

It returns the executed operation and an error.

Example

This example creates or updates an existing deployment

package main

import (
	"context"

	appsv1 "k8s.io/api/apps/v1"
	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"

	"sigs.k8s.io/controller-runtime/pkg/controller/controllerutil"
	logf "sigs.k8s.io/controller-runtime/pkg/log"
)

var (
	log = logf.Log.WithName("controllerutil-examples")
)

// This example creates or updates an existing deployment
func main() {
	// c is client.Client

	// Create or Update the deployment default/foo
	deploy := &appsv1.Deployment{ObjectMeta: metav1.ObjectMeta{Name: "foo", Namespace: "default"}}

	op, err := controllerutil.CreateOrUpdate(context.TODO(), c, deploy, func() error {

		// Deployment selector is immutable so we set this value only if
		// a new object is going to be created
		if deploy.ObjectMeta.CreationTimestamp.IsZero() {
			deploy.Spec.Selector = &metav1.LabelSelector{
				MatchLabels: map[string]string{"foo": "bar"},
			}
		}

		// update the Deployment pod template
		deploy.Spec.Template = corev1.PodTemplateSpec{
			ObjectMeta: metav1.ObjectMeta{
				Labels: map[string]string{
					"foo": "bar",
				},
			},
			Spec: corev1.PodSpec{
				Containers: []corev1.Container{
					{
						Name:  "busybox",
						Image: "busybox",
					},
				},
			},
		}

		return nil
	})

	if err != nil {
		log.Error(err, "Deployment reconcile failed")
	} else {
		log.Info("Deployment successfully reconciled", "operation", op)
	}
}