builder

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

• type Builder
  • func ControllerManagedBy(m manager.Manager) *Builder
  • func SimpleController() *Builder
  • func (blder *Builder) Build(r reconcile.Reconciler) (manager.Manager, error)
  • func (blder *Builder) Complete(r reconcile.Reconciler) error
  • func (blder *Builder) For(apiType runtime.Object) *Builder
  • func (blder *Builder) ForType(apiType runtime.Object) *Builder
  • func (blder *Builder) Owns(apiType runtime.Object) *Builder
  • func (blder *Builder) Watches(src source.Source, eventhandler handler.EventHandler) *Builder
  • func (blder *Builder) WithConfig(config *rest.Config) *Builder
  • func (blder *Builder) WithEventFilter(p predicate.Predicate) *Builder
  • func (blder *Builder) WithManager(m manager.Manager) *Builder

Examples

• Builder

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

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

	// List the Pods matching the PodTemplate Labels
	pods := &corev1.PodList{}
	err = a.List(context.TODO(), client.InNamespace(req.Namespace).MatchingLabels(rs.Spec.Template.Labels), pods)
	if err != nil {
		return reconcile.Result{}, err
	}

	// Update the ReplicaSet
	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
}

func ControllerManagedBy

func ControllerManagedBy(m manager.Manager) *Builder

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

func SimpleController

func SimpleController() *Builder

SimpleController returns a new Builder. Deprecated: Use ControllerManagedBy(Manager) instead.

func (*Builder) Build

func (blder *Builder) Build(r reconcile.Reconciler) (manager.Manager, error)

Build builds the Application ControllerManagedBy and returns the Manager used to start it. Deprecated: Use Complete

func (*Builder) Complete

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

Complete builds the Application ControllerManagedBy and returns the Manager used to start it.

func (*Builder) For

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

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) 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(&handler.EnqueueRequestForOwner{&source.Kind{Type: <ForType-apiType>}, &handler.EnqueueRequestForOwner{OwnerType: apiType, IsController: true})

func (*Builder) Watches

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

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) WithManager

func (blder *Builder) WithManager(m manager.Manager) *Builder

WithManager sets the Manager to use for registering the ControllerManagedBy. Defaults to a new manager.Manager. Deprecated: Use ControllerManagedBy(Manager) and this isn't needed.