Documentation
¶
Overview ¶
Package predicate defines Predicates used by Controllers to filter Events before they are provided to EventHandlers.
Index ¶
Examples ¶
Constants ¶
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Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type AnnotationChangedPredicate ¶ added in v1.0.1
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 v1.0.1
func (AnnotationChangedPredicate) Update(e event.UpdateEvent) bool
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 (
"github.com/samuelkuklis/controller-runtime/pkg/event"
"github.com/samuelkuklis/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 v1.0.1
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.
type GenerationChangedPredicate ¶ added in v1.0.1
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 v1.0.1
func (GenerationChangedPredicate) Update(e event.UpdateEvent) bool
Update implements default UpdateEvent filter for validating generation change.
type LabelChangedPredicate ¶ added in v1.0.1
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 v1.0.1
func (LabelChangedPredicate) Update(e event.UpdateEvent) bool
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 v1.0.1
And returns a composite predicate that implements a logical AND of the predicates passed to it.
func LabelSelectorPredicate ¶ added in v1.0.1
func LabelSelectorPredicate(s metav1.LabelSelector) (Predicate, error)
LabelSelectorPredicate constructs a Predicate from a LabelSelector. Only objects matching the LabelSelector will be admitted.
type ResourceVersionChangedPredicate ¶
type ResourceVersionChangedPredicate struct {
Funcs
}
ResourceVersionChangedPredicate implements a default update predicate function on resource version change.
func (ResourceVersionChangedPredicate) Update ¶
func (ResourceVersionChangedPredicate) Update(e event.UpdateEvent) bool
Update implements default UpdateEvent filter for validating resource version change.
Source Files