builder

package
v0.5.13 Latest Latest
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 Go to latest Published: Dec 1, 2020 License: Apache-2.0 Imports: 18 Imported by: 1,535

Documentation

Overview

Package builder provides 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

This section is empty.

Functions

func OnlyMetadata added in v0.5.12 

func OnlyMetadata(obj runtime.Object) runtime.Object

OnlyMetadata tells the controller to *only* cache metadata, and to watch the 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 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.

Types

type Builder 

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

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"

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

	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"
	"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())

	var 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{})
	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(req reconcile.Request) (reconcile.Result, error) {

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

	pods := &corev1.PodList{}
	err = a.List(context.TODO(), 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(context.TODO(), rs)
	if err != nil {
		return reconcile.Result{}, err
	}

	return reconcile.Result{}, nil
}

func (a *ReplicaSetReconciler) InjectClient(c client.Client) error {
	a.Client = c
	return nil
}

Output:
Example (Metadata_only) 
package main

import (
	"context"
	"fmt"
	"os"

	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	logf "sigs.k8s.io/controller-runtime/pkg/log"

	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"
	"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())

	var 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(builder.OnlyMetadata(&corev1.Pod{})). // ReplicaSet owns Pods created by it, and caches them as metadata only
		Complete(reconcile.Func(func(req reconcile.Request) (reconcile.Result, error) {
			ctx, cancel := context.WithCancel(context.Background())
			defer cancel()

			// 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

func (*Builder) Build 

func (blder *Builder) Build(r reconcile.Reconciler) (controller.Controller, error)

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

func (*Builder) Complete added in v0.1.10 

func (blder *Builder) Complete(r reconcile.Reconciler) error

Complete builds the Application ControllerManagedBy.

func (*Builder) For added in v0.1.10 

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

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{Type: apiType}, &handler.EnqueueRequestForObject{})

func (*Builder) ForType deprecated 

func (blder *Builder) ForType(apiType runtime.Object) *Builder

ForType 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{Type: apiType}, &handler.EnqueueRequestForObject{})

Deprecated: Use For

func (*Builder) Named added in v0.2.0 

func (blder *Builder) Named(name string) *Builder

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.

func (*Builder) Owns 

func (blder *Builder) Owns(apiType runtime.Object) *Builder

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*. This is the equivalent of calling Watches(&source.Kind{Type: <ForType-apiType>}, &handler.EnqueueRequestForOwner{OwnerType: apiType, IsController: true})

func (*Builder) Watches added in v0.1.10 

func (blder *Builder) Watches(src source.Source, eventhandler handler.EventHandler) *Builder

Watches exposes the lower-level ControllerManagedBy Watches functions through the builder. Consider using Owns or For instead of Watches directly.

func (*Builder) WithConfig deprecated 

func (blder *Builder) WithConfig(config *rest.Config) *Builder

WithConfig sets the Config to use for configuring clients. Defaults to the in-cluster config or to ~/.kube/config.

Deprecated: Use ControllerManagedBy(Manager) and this isn't needed.

func (*Builder) WithEventFilter 

func (blder *Builder) WithEventFilter(p predicate.Predicate) *Builder

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. Defaults to the empty list.

func (*Builder) WithOptions added in v0.2.0 

func (blder *Builder) WithOptions(options controller.Options) *Builder

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

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"
	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"

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

// examplegroup.ChaosPod has implemented both admission.Defaulter and
// admission.Validator interfaces.
var _ admission.Defaulter = &examplegroup.ChaosPod{}
var _ admission.Validator = &examplegroup.ChaosPod{}

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

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.

Source Files

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