syncer

Documentation

Index

• func Sync(ctx context.Context, syncer Interface, recorder record.EventRecorder) error
• type Interface
  • func NewExternalSyncer(name string, owner runtime.Object, obj interface{}, ...) Interface
  • func NewObjectSyncer(name string, owner, obj runtime.Object, c client.Client, ...) Interface
• type SyncResult
  • func (r *SyncResult) SetEventData(eventType, reason, message string)
• type WithoutOwner
  • func (*WithoutOwner) GetOwner() runtime.Object

Examples

• NewObjectSyncer

Functions

func Sync

func Sync(ctx context.Context, syncer Interface, recorder record.EventRecorder) error

Sync mutates the subject of the syncer interface using controller-runtime CreateOrUpdate method, when obj is not nil. It takes care of setting owner references and recording kubernetes events where appropriate

Types

type Interface

type Interface interface {
	// GetObject returns the object for which sync applies
	GetObject() interface{}
	// GetOwner returns the object owner or nil if object does not have one
	GetOwner() runtime.Object
	// Sync persists data into the external store
	Sync(context.Context) (SyncResult, error)
}

Interface represents a syncer. A syncer persists an object (known as subject), into a store (kubernetes apiserver or generic stores) and records kubernetes events

func NewExternalSyncer

func NewExternalSyncer(name string, owner runtime.Object, obj interface{}, syncFn func(context.Context, interface{}) (controllerutil.OperationResult, error)) Interface

NewExternalSyncer creates a new syncer which syncs a generic object persisting it's state into and external store The name is used for logging and event emitting purposes and should be an valid go identifier in upper camel case. (eg. GiteaRepo)

func NewObjectSyncer

func NewObjectSyncer(name string, owner, obj runtime.Object, c client.Client, scheme *runtime.Scheme, syncFn controllerutil.MutateFn) Interface

NewObjectSyncer creates a new kubernetes object syncer for a given object with an owner and persists data using controller-runtime's CreateOrUpdate. The name is used for logging and event emitting purposes and should be an valid go identifier in upper camel case. (eg. MysqlStatefulSet)

Example

package main

import (
	"context"

	appsv1 "k8s.io/api/apps/v1"
	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/client-go/tools/record"
	"sigs.k8s.io/controller-runtime/pkg/client"
	logf "sigs.k8s.io/controller-runtime/pkg/runtime/log"

	"github.com/presslabs/controller-util/syncer"
)

var (
	c        client.Client
	scheme   *runtime.Scheme
	recorder record.EventRecorder
	owner    runtime.Object
	log      = logf.Log.WithName("controllerutil-examples")
)

func NewDeploymentSyncer(owner runtime.Object) syncer.Interface {
	obj := &appsv1.Deployment{
		ObjectMeta: metav1.ObjectMeta{
			Name:      "example",
			Namespace: "default",
		},
	}

	// c is client.Client
	// scheme is *runtime.Scheme
	return syncer.NewObjectSyncer("ExampleDeployment", owner, obj, c, scheme, func(existing runtime.Object) error {
		deploy := existing.(*appsv1.Deployment)

		// 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
	})
}

func main() {
	// recorder is record.EventRecorder
	// owner is the owner for the syncer subject

	deploymentSyncer := NewDeploymentSyncer(owner)
	err := syncer.Sync(context.TODO(), deploymentSyncer, recorder)
	if err != nil {
		log.Error(err, "unable to sync")
	}
}

type SyncResult

type SyncResult struct {
	Operation    controllerutil.OperationResult
	EventType    string
	EventReason  string
	EventMessage string
}

SyncResult is a result of an Sync call

func (*SyncResult) SetEventData

func (r *SyncResult) SetEventData(eventType, reason, message string)

SetEventData sets event data on an SyncResult

type WithoutOwner

type WithoutOwner struct{}

WithoutOwner partially implements implements the syncer interface for the case the subject has no owner

func (*WithoutOwner) GetOwner

func (*WithoutOwner) GetOwner() runtime.Object

GetOwner implementation of syncer interface for the case the subject has no owner