builder

package
v0.19.0 Latest Latest
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 Go to latest Published: Aug 13, 2024 License: Apache-2.0 Imports: 23 Imported by: 1,504

Documentation

Overview

Package builder wraps other controller-runtime libraries and exposes simple patterns for building common Controllers.

Projects built with the builder package can trivially be rebased on top of the underlying packages if the project requires more customized behavior in the future.

Index

Examples

Constants

This section is empty.

Variables

View Source 
var MatchEveryOwner = &matchEveryOwner{}

MatchEveryOwner determines whether the watch should be filtered based on controller ownership. As in, when the OwnerReference.Controller field is set.

If passed as an option, the handler receives notification for every owner of the object with the given type. If unset (default), the handler receives notification only for the first OwnerReference with `Controller: true`.

View Source 
var (
	// OnlyMetadata tells the controller to *only* cache metadata, and to watch
	// the API server in metadata-only form. This is useful when watching
	// lots of objects, really big objects, or objects for which you only know
	// the GVK, but not the structure. You'll need to pass
	// metav1.PartialObjectMetadata to the client when fetching objects in your
	// reconciler, otherwise you'll end up with a duplicate structured or
	// unstructured cache.
	//
	// When watching a resource with OnlyMetadata, for example the v1.Pod, you
	// should not Get and List using the v1.Pod type. Instead, you should use
	// the special metav1.PartialObjectMetadata type.
	//
	// ❌ Incorrect:
	//
	//   pod := &v1.Pod{}
	//   mgr.GetClient().Get(ctx, nsAndName, pod)
	//
	// ✅ Correct:
	//
	//   pod := &metav1.PartialObjectMetadata{}
	//   pod.SetGroupVersionKind(schema.GroupVersionKind{
	//       Group:   "",
	//       Version: "v1",
	//       Kind:    "Pod",
	//   })
	//   mgr.GetClient().Get(ctx, nsAndName, pod)
	//
	// In the first case, controller-runtime will create another cache for the
	// concrete type on top of the metadata cache; this increases memory
	// consumption and leads to race conditions as caches are not in sync.
	OnlyMetadata = projectAs(projectAsMetadata)
)

Functions

This section is empty.

Types

type Builder 

type Builder = TypedBuilder[reconcile.Request]

Builder builds a Controller.

Example

This example creates a simple application ControllerManagedBy that is configured for ReplicaSets and Pods.

* Create a new application for ReplicaSets that manages Pods owned by the ReplicaSet and calls into ReplicaSetReconciler.

* Start the application. 

package main

import (
	"context"
	"fmt"
	"os"

	appsv1 "k8s.io/api/apps/v1"
	corev1 "k8s.io/api/core/v1"

	"sigs.k8s.io/controller-runtime/pkg/builder"
	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/client/config"

	logf "sigs.k8s.io/controller-runtime/pkg/log"
	"sigs.k8s.io/controller-runtime/pkg/log/zap"
	"sigs.k8s.io/controller-runtime/pkg/manager"
	"sigs.k8s.io/controller-runtime/pkg/manager/signals"
	"sigs.k8s.io/controller-runtime/pkg/reconcile"
)

func main() {
	logf.SetLogger(zap.New())

	log := logf.Log.WithName("builder-examples")

	mgr, err := manager.New(config.GetConfigOrDie(), manager.Options{})
	if err != nil {
		log.Error(err, "could not create manager")
		os.Exit(1)
	}

	err = builder.
		ControllerManagedBy(mgr).  // Create the ControllerManagedBy
		For(&appsv1.ReplicaSet{}). // ReplicaSet is the Application API
		Owns(&corev1.Pod{}).       // ReplicaSet owns Pods created by it
		Complete(&ReplicaSetReconciler{
			Client: mgr.GetClient(),
		})
	if err != nil {
		log.Error(err, "could not create controller")
		os.Exit(1)
	}

	if err := mgr.Start(signals.SetupSignalHandler()); err != nil {
		log.Error(err, "could not start manager")
		os.Exit(1)
	}
}

// ReplicaSetReconciler is a simple ControllerManagedBy example implementation.
type ReplicaSetReconciler struct {
	client.Client
}

// Implement the business logic:
// This function will be called when there is a change to a ReplicaSet or a Pod with an OwnerReference
// to a ReplicaSet.
//
// * Read the ReplicaSet
// * Read the Pods
// * Set a Label on the ReplicaSet with the Pod count.
func (a *ReplicaSetReconciler) Reconcile(ctx context.Context, req reconcile.Request) (reconcile.Result, error) {

	rs := &appsv1.ReplicaSet{}
	err := a.Get(ctx, req.NamespacedName, rs)
	if err != nil {
		return reconcile.Result{}, err
	}

	pods := &corev1.PodList{}
	err = a.List(ctx, pods, client.InNamespace(req.Namespace), client.MatchingLabels(rs.Spec.Template.Labels))
	if err != nil {
		return reconcile.Result{}, err
	}

	rs.Labels["pod-count"] = fmt.Sprintf("%v", len(pods.Items))
	err = a.Update(ctx, rs)
	if err != nil {
		return reconcile.Result{}, err
	}

	return reconcile.Result{}, nil
}

Output:
Example (Metadata_only) 
package main

import (
	"context"
	"fmt"
	"os"

	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/builder"
	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/client/config"

	logf "sigs.k8s.io/controller-runtime/pkg/log"
	"sigs.k8s.io/controller-runtime/pkg/log/zap"
	"sigs.k8s.io/controller-runtime/pkg/manager"
	"sigs.k8s.io/controller-runtime/pkg/manager/signals"
	"sigs.k8s.io/controller-runtime/pkg/reconcile"
)

func main() {
	logf.SetLogger(zap.New())

	log := logf.Log.WithName("builder-examples")

	mgr, err := manager.New(config.GetConfigOrDie(), manager.Options{})
	if err != nil {
		log.Error(err, "could not create manager")
		os.Exit(1)
	}

	cl := mgr.GetClient()
	err = builder.
		ControllerManagedBy(mgr).                  // Create the ControllerManagedBy
		For(&appsv1.ReplicaSet{}).                 // ReplicaSet is the Application API
		Owns(&corev1.Pod{}, builder.OnlyMetadata). // ReplicaSet owns Pods created by it, and caches them as metadata only
		Complete(reconcile.Func(func(ctx context.Context, req reconcile.Request) (reconcile.Result, error) {
			// Read the ReplicaSet
			rs := &appsv1.ReplicaSet{}
			err := cl.Get(ctx, req.NamespacedName, rs)
			if err != nil {
				return reconcile.Result{}, client.IgnoreNotFound(err)
			}

			// List the Pods matching the PodTemplate Labels, but only their metadata
			var podsMeta metav1.PartialObjectMetadataList
			err = cl.List(ctx, &podsMeta, client.InNamespace(req.Namespace), client.MatchingLabels(rs.Spec.Template.Labels))
			if err != nil {
				return reconcile.Result{}, client.IgnoreNotFound(err)
			}

			// Update the ReplicaSet
			rs.Labels["pod-count"] = fmt.Sprintf("%v", len(podsMeta.Items))
			err = cl.Update(ctx, rs)
			if err != nil {
				return reconcile.Result{}, err
			}

			return reconcile.Result{}, nil
		}))
	if err != nil {
		log.Error(err, "could not create controller")
		os.Exit(1)
	}

	if err := mgr.Start(signals.SetupSignalHandler()); err != nil {
		log.Error(err, "could not start manager")
		os.Exit(1)
	}
}

Output:

func ControllerManagedBy added in v0.1.10 

func ControllerManagedBy(m manager.Manager) *Builder

ControllerManagedBy returns a new controller builder that will be started by the provided Manager.

type ForInput added in v0.6.0 

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

ForInput represents the information set by the For method.

type ForOption added in v0.6.0 

type ForOption interface {
	// ApplyToFor applies this configuration to the given for input.
	ApplyToFor(*ForInput)
}

ForOption is some configuration that modifies options for a For request.

type OwnsInput added in v0.6.0 

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

OwnsInput represents the information set by Owns method.

type OwnsOption added in v0.6.0 

type OwnsOption interface {
	// ApplyToOwns applies this configuration to the given owns input.
	ApplyToOwns(*OwnsInput)
}

OwnsOption is some configuration that modifies options for an owns request.

type Predicates added in v0.6.0 

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

Predicates filters events before enqueuing the keys.

func WithPredicates added in v0.6.0 

func WithPredicates(predicates ...predicate.Predicate) Predicates

WithPredicates sets the given predicates list.

func (Predicates) ApplyToFor added in v0.6.0 

func (w Predicates) ApplyToFor(opts *ForInput)

ApplyToFor applies this configuration to the given ForInput options.

func (Predicates) ApplyToOwns added in v0.6.0 

func (w Predicates) ApplyToOwns(opts *OwnsInput)

ApplyToOwns applies this configuration to the given OwnsInput options.

func (Predicates) ApplyToWatches added in v0.6.0 

func (w Predicates) ApplyToWatches(opts untypedWatchesInput)

ApplyToWatches applies this configuration to the given WatchesInput options.

type TypedBuilder added in v0.19.0 

type TypedBuilder[request comparable] struct {
	// contains filtered or unexported fields
}

TypedBuilder builds a Controller. The request is the request type that is passed to the workqueue and then to the Reconciler. The workqueue de-duplicates identical requests.

func TypedControllerManagedBy added in v0.19.0 

func TypedControllerManagedBy[request comparable](m manager.Manager) *TypedBuilder[request]

TypedControllerManagedBy returns a new typed controller builder that will be started by the provided Manager.

func (*TypedBuilder[request]) Build added in v0.19.0 

func (blder *TypedBuilder[request]) Build(r reconcile.TypedReconciler[request]) (controller.TypedController[request], error)

Build builds the Application Controller and returns the Controller it created.

func (*TypedBuilder[request]) Complete added in v0.19.0 

func (blder *TypedBuilder[request]) Complete(r reconcile.TypedReconciler[request]) error

Complete builds the Application Controller.

func (*TypedBuilder[request]) For added in v0.19.0 

func (blder *TypedBuilder[request]) For(object client.Object, opts ...ForOption) *TypedBuilder[request]

For defines the type of Object being *reconciled*, and configures the ControllerManagedBy to respond to create / delete / update events by *reconciling the object*.

This is the equivalent of calling Watches(source.Kind(cache, &Type{}, &handler.EnqueueRequestForObject{})).

func (*TypedBuilder[request]) Named added in v0.19.0 

func (blder *TypedBuilder[request]) Named(name string) *TypedBuilder[request]

Named sets the name of the controller to the given name. The name shows up in metrics, among other things, and thus should be a prometheus compatible name (underscores and alphanumeric characters only).

By default, controllers are named using the lowercase version of their kind.

The name must be unique as it is used to identify the controller in metrics and logs.

func (*TypedBuilder[request]) Owns added in v0.19.0 

func (blder *TypedBuilder[request]) Owns(object client.Object, opts ...OwnsOption) *TypedBuilder[request]

Owns defines types of Objects being *generated* by the ControllerManagedBy, and configures the ControllerManagedBy to respond to create / delete / update events by *reconciling the owner object*.

The default behavior reconciles only the first controller-type OwnerReference of the given type. Use Owns(object, builder.MatchEveryOwner) to reconcile all owners.

By default, this is the equivalent of calling Watches(source.Kind(cache, &Type{}, handler.EnqueueRequestForOwner([...], &OwnerType{}, OnlyControllerOwner()))).

func (*TypedBuilder[request]) Watches added in v0.19.0 

func (blder *TypedBuilder[request]) Watches(
	object client.Object,
	eventHandler handler.TypedEventHandler[client.Object, request],
	opts ...WatchesOption,
) *TypedBuilder[request]

Watches defines the type of Object to watch, and configures the ControllerManagedBy to respond to create / delete / update events by *reconciling the object* with the given EventHandler.

This is the equivalent of calling WatchesRawSource(source.Kind(cache, object, eventHandler, predicates...)).

func (*TypedBuilder[request]) WatchesMetadata added in v0.19.0 

func (blder *TypedBuilder[request]) WatchesMetadata(
	object client.Object,
	eventHandler handler.TypedEventHandler[client.Object, request],
	opts ...WatchesOption,
) *TypedBuilder[request]

WatchesMetadata is the same as Watches, but forces the internal cache to only watch PartialObjectMetadata.

This is useful when watching lots of objects, really big objects, or objects for which you only know the GVK, but not the structure. You'll need to pass metav1.PartialObjectMetadata to the client when fetching objects in your reconciler, otherwise you'll end up with a duplicate structured or unstructured cache.

When watching a resource with metadata only, for example the v1.Pod, you should not Get and List using the v1.Pod type. Instead, you should use the special metav1.PartialObjectMetadata type.

❌ Incorrect: 

pod := &v1.Pod{}
mgr.GetClient().Get(ctx, nsAndName, pod)

✅ Correct: 

pod := &metav1.PartialObjectMetadata{}
pod.SetGroupVersionKind(schema.GroupVersionKind{
    Group:   "",
    Version: "v1",
    Kind:    "Pod",
})
mgr.GetClient().Get(ctx, nsAndName, pod)

In the first case, controller-runtime will create another cache for the concrete type on top of the metadata cache; this increases memory consumption and leads to race conditions as caches are not in sync.

func (*TypedBuilder[request]) WatchesRawSource added in v0.19.0 

func (blder *TypedBuilder[request]) WatchesRawSource(src source.TypedSource[request]) *TypedBuilder[request]

WatchesRawSource exposes the lower-level ControllerManagedBy Watches functions through the builder.

WatchesRawSource does not respect predicates configured through WithEventFilter.

WatchesRawSource makes it possible to use typed handlers and predicates with `source.Kind` as well as custom source implementations.

func (*TypedBuilder[request]) WithEventFilter added in v0.19.0 

func (blder *TypedBuilder[request]) WithEventFilter(p predicate.Predicate) *TypedBuilder[request]

WithEventFilter sets the event filters, to filter which create/update/delete/generic events eventually trigger reconciliations. For example, filtering on whether the resource version has changed. Given predicate is added for all watched objects and thus must be able to deal with the type of all watched objects.

Defaults to the empty list.

func (*TypedBuilder[request]) WithLogConstructor added in v0.19.0 

func (blder *TypedBuilder[request]) WithLogConstructor(logConstructor func(*request) logr.Logger) *TypedBuilder[request]

WithLogConstructor overrides the controller options's LogConstructor.

func (*TypedBuilder[request]) WithOptions added in v0.19.0 

func (blder *TypedBuilder[request]) WithOptions(options controller.TypedOptions[request]) *TypedBuilder[request]

WithOptions overrides the controller options used in doController. Defaults to empty.

type WatchesInput added in v0.6.0 

type WatchesInput[request comparable] struct {
	// contains filtered or unexported fields
}

WatchesInput represents the information set by Watches method.

type WatchesOption added in v0.6.0 

type WatchesOption interface {
	// ApplyToWatches applies this configuration to the given watches options.
	ApplyToWatches(untypedWatchesInput)
}

WatchesOption is some configuration that modifies options for a watches request.

type WebhookBuilder added in v0.2.0 

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

WebhookBuilder builds a Webhook.

Example

This example use webhook builder to create a simple webhook that is managed by a manager for CRD ChaosPod. And then start the manager. 

package main

import (
	"os"

	"sigs.k8s.io/controller-runtime/pkg/builder"
	"sigs.k8s.io/controller-runtime/pkg/client/config"

	logf "sigs.k8s.io/controller-runtime/pkg/log"
	"sigs.k8s.io/controller-runtime/pkg/manager"
	"sigs.k8s.io/controller-runtime/pkg/manager/signals"

	examplegroup "sigs.k8s.io/controller-runtime/examples/crd/pkg"
)

func main() {
	var log = logf.Log.WithName("webhookbuilder-example")

	mgr, err := manager.New(config.GetConfigOrDie(), manager.Options{})
	if err != nil {
		log.Error(err, "could not create manager")
		os.Exit(1)
	}

	err = builder.
		WebhookManagedBy(mgr).         // Create the WebhookManagedBy
		For(&examplegroup.ChaosPod{}). // ChaosPod is a CRD.
		Complete()
	if err != nil {
		log.Error(err, "could not create webhook")
		os.Exit(1)
	}

	if err := mgr.Start(signals.SetupSignalHandler()); err != nil {
		log.Error(err, "could not start manager")
		os.Exit(1)
	}
}

Output:

func WebhookManagedBy added in v0.2.0 

func WebhookManagedBy(m manager.Manager) *WebhookBuilder

WebhookManagedBy returns a new webhook builder.

func (*WebhookBuilder) Complete added in v0.2.0 

func (blder *WebhookBuilder) Complete() error

Complete builds the webhook.

func (*WebhookBuilder) For added in v0.2.0 

func (blder *WebhookBuilder) For(apiType runtime.Object) *WebhookBuilder

For takes a runtime.Object which should be a CR. If the given object implements the admission.Defaulter interface, a MutatingWebhook will be wired for this type. If the given object implements the admission.Validator interface, a ValidatingWebhook will be wired for this type.

func (*WebhookBuilder) RecoverPanic added in v0.13.0 

func (blder *WebhookBuilder) RecoverPanic(recoverPanic bool) *WebhookBuilder

RecoverPanic indicates whether panics caused by the webhook should be recovered. Defaults to true.

func (*WebhookBuilder) WithDefaulter added in v0.10.2 

func (blder *WebhookBuilder) WithDefaulter(defaulter admission.CustomDefaulter) *WebhookBuilder

WithDefaulter takes an admission.CustomDefaulter interface, a MutatingWebhook will be wired for this type.

func (*WebhookBuilder) WithLogConstructor added in v0.15.0 

func (blder *WebhookBuilder) WithLogConstructor(logConstructor func(base logr.Logger, req *admission.Request) logr.Logger) *WebhookBuilder

WithLogConstructor overrides the webhook's LogConstructor.

func (*WebhookBuilder) WithValidator added in v0.10.2 

func (blder *WebhookBuilder) WithValidator(validator admission.CustomValidator) *WebhookBuilder

WithValidator takes a admission.CustomValidator interface, a ValidatingWebhook will be wired for this type.

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