predicate

package
Version: v0.10.3 Latest Latest
Warning

This package is not in the latest version of its module.

Go to latest
Published: Nov 10, 2021 License: Apache-2.0 Imports: 6 Imported by: 1,240

Documentation

Overview

Package predicate defines Predicates used by Controllers to filter Events before they are provided to EventHandlers.

Index

Examples

Constants

This section is empty.

Variables

This section is empty.

Functions

This section is empty.

Types

type AnnotationChangedPredicate added in v0.7.0

type AnnotationChangedPredicate struct {
	Funcs
}

AnnotationChangedPredicate implements a default update predicate function on annotation change.

This predicate will skip update events that have no change in the object's annotation. It is intended to be used in conjunction with the GenerationChangedPredicate, as in the following example:

Controller.Watch(

&source.Kind{Type: v1.MyCustomKind},
&handler.EnqueueRequestForObject{},
predicate.Or(predicate.GenerationChangedPredicate{}, predicate.AnnotationChangedPredicate{}))

This is mostly useful for controllers that needs to trigger both when the resource's generation is incremented (i.e., when the resource' .spec changes), or an annotation changes (e.g., for a staging/alpha API).

func (AnnotationChangedPredicate) Update added in v0.7.0

Update implements default UpdateEvent filter for validating annotation change.

type Funcs

type Funcs struct {
	// Create returns true if the Create event should be processed
	CreateFunc func(event.CreateEvent) bool

	// Delete returns true if the Delete event should be processed
	DeleteFunc func(event.DeleteEvent) bool

	// Update returns true if the Update event should be processed
	UpdateFunc func(event.UpdateEvent) bool

	// Generic returns true if the Generic event should be processed
	GenericFunc func(event.GenericEvent) bool
}

Funcs is a function that implements Predicate.

Example

This example creates a new Predicate to drop Update Events where the Generation has not changed.

package main

import (
	"sigs.k8s.io/controller-runtime/pkg/event"
	"sigs.k8s.io/controller-runtime/pkg/predicate"
)

var p predicate.Predicate

// This example creates a new Predicate to drop Update Events where the Generation has not changed.
func main() {
	p = predicate.Funcs{
		UpdateFunc: func(e event.UpdateEvent) bool {
			return e.ObjectOld.GetGeneration() != e.ObjectNew.GetGeneration()
		},
	}
}
Output:

func NewPredicateFuncs added in v0.6.2

func NewPredicateFuncs(filter func(object client.Object) bool) Funcs

NewPredicateFuncs returns a predicate funcs that applies the given filter function on CREATE, UPDATE, DELETE and GENERIC events. For UPDATE events, the filter is applied to the new object.

func (Funcs) Create

func (p Funcs) Create(e event.CreateEvent) bool

Create implements Predicate.

func (Funcs) Delete

func (p Funcs) Delete(e event.DeleteEvent) bool

Delete implements Predicate.

func (Funcs) Generic

func (p Funcs) Generic(e event.GenericEvent) bool

Generic implements Predicate.

func (Funcs) Update

func (p Funcs) Update(e event.UpdateEvent) bool

Update implements Predicate.

type GenerationChangedPredicate added in v0.2.0

type GenerationChangedPredicate struct {
	Funcs
}

GenerationChangedPredicate implements a default update predicate function on Generation change.

This predicate will skip update events that have no change in the object's metadata.generation field. The metadata.generation field of an object is incremented by the API server when writes are made to the spec field of an object. This allows a controller to ignore update events where the spec is unchanged, and only the metadata and/or status fields are changed.

For CustomResource objects the Generation is only incremented when the status subresource is enabled.

Caveats:

* The assumption that the Generation is incremented only on writing to the spec does not hold for all APIs. E.g For Deployment objects the Generation is also incremented on writes to the metadata.annotations field. For object types other than CustomResources be sure to verify which fields will trigger a Generation increment when they are written to.

* With this predicate, any update events with writes only to the status field will not be reconciled. So in the event that the status block is overwritten or wiped by someone else the controller will not self-correct to restore the correct status.

func (GenerationChangedPredicate) Update added in v0.2.0

Update implements default UpdateEvent filter for validating generation change.

type LabelChangedPredicate added in v0.8.0

type LabelChangedPredicate struct {
	Funcs
}

LabelChangedPredicate implements a default update predicate function on label change.

This predicate will skip update events that have no change in the object's label. It is intended to be used in conjunction with the GenerationChangedPredicate, as in the following example:

Controller.Watch(

&source.Kind{Type: v1.MyCustomKind},
&handler.EnqueueRequestForObject{},
predicate.Or(predicate.GenerationChangedPredicate{}, predicate.LabelChangedPredicate{}))

This will be helpful when object's labels is carrying some extra specification information beyond object's spec, and the controller will be triggered if any valid spec change (not only in spec, but also in labels) happens.

func (LabelChangedPredicate) Update added in v0.8.0

Update implements default UpdateEvent filter for checking label change.

type Predicate

type Predicate interface {
	// Create returns true if the Create event should be processed
	Create(event.CreateEvent) bool

	// Delete returns true if the Delete event should be processed
	Delete(event.DeleteEvent) bool

	// Update returns true if the Update event should be processed
	Update(event.UpdateEvent) bool

	// Generic returns true if the Generic event should be processed
	Generic(event.GenericEvent) bool
}

Predicate filters events before enqueuing the keys.

func And added in v0.5.9

func And(predicates ...Predicate) Predicate

And returns a composite predicate that implements a logical AND of the predicates passed to it.

func LabelSelectorPredicate added in v0.7.0

func LabelSelectorPredicate(s metav1.LabelSelector) (Predicate, error)

LabelSelectorPredicate constructs a Predicate from a LabelSelector. Only objects matching the LabelSelector will be admitted.

func Or added in v0.5.9

func Or(predicates ...Predicate) Predicate

Or returns a composite predicate that implements a logical OR of the predicates passed to it.

type ResourceVersionChangedPredicate

type ResourceVersionChangedPredicate struct {
	Funcs
}

ResourceVersionChangedPredicate implements a default update predicate function on resource version change.

func (ResourceVersionChangedPredicate) Update

Update implements default UpdateEvent filter for validating resource version change.

Jump to

Keyboard shortcuts

? : This menu
/ : Search site
f or F : Jump to
y or Y : Canonical URL