Initial v1.0.0 commit

vendor/sigs.k8s.io/controller-runtime/pkg/builder/controller.go

@@ -0,0 +1,311 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package builder
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/go-logr/logr"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/client-go/rest"
+
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/client/apiutil"
+	"sigs.k8s.io/controller-runtime/pkg/controller"
+	"sigs.k8s.io/controller-runtime/pkg/handler"
+	"sigs.k8s.io/controller-runtime/pkg/manager"
+	"sigs.k8s.io/controller-runtime/pkg/predicate"
+	"sigs.k8s.io/controller-runtime/pkg/reconcile"
+	"sigs.k8s.io/controller-runtime/pkg/source"
+)
+
+// Supporting mocking out functions for testing
+var newController = controller.New
+var getGvk = apiutil.GVKForObject
+
+// project represents other forms that the we can use to
+// send/receive a given resource (metadata-only, unstructured, etc)
+type objectProjection int
+
+const (
+	// projectAsNormal doesn't change the object from the form given
+	projectAsNormal objectProjection = iota
+	// projectAsMetadata turns this into an metadata-only watch
+	projectAsMetadata
+)
+
+// Builder builds a Controller.
+type Builder struct {
+	forInput         ForInput
+	ownsInput        []OwnsInput
+	watchesInput     []WatchesInput
+	mgr              manager.Manager
+	globalPredicates []predicate.Predicate
+	config           *rest.Config
+	ctrl             controller.Controller
+	ctrlOptions      controller.Options
+	name             string
+}
+
+// ControllerManagedBy returns a new controller builder that will be started by the provided Manager
+func ControllerManagedBy(m manager.Manager) *Builder {
+	return &Builder{mgr: m}
+}
+
+// ForInput represents the information set by For method.
+type ForInput struct {
+	object           client.Object
+	predicates       []predicate.Predicate
+	objectProjection objectProjection
+	err              error
+}
+
+// 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 (blder *Builder) For(object client.Object, opts ...ForOption) *Builder {
+	if blder.forInput.object != nil {
+		blder.forInput.err = fmt.Errorf("For(...) should only be called once, could not assign multiple objects for reconciliation")
+		return blder
+	}
+	input := ForInput{object: object}
+	for _, opt := range opts {
+		opt.ApplyToFor(&input)
+	}
+
+	blder.forInput = input
+	return blder
+}
+
+// OwnsInput represents the information set by Owns method.
+type OwnsInput struct {
+	object           client.Object
+	predicates       []predicate.Predicate
+	objectProjection objectProjection
+}
+
+// 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-forInput>}, &handler.EnqueueRequestForOwner{OwnerType: apiType, IsController: true})
+func (blder *Builder) Owns(object client.Object, opts ...OwnsOption) *Builder {
+	input := OwnsInput{object: object}
+	for _, opt := range opts {
+		opt.ApplyToOwns(&input)
+	}
+
+	blder.ownsInput = append(blder.ownsInput, input)
+	return blder
+}
+
+// WatchesInput represents the information set by Watches method.
+type WatchesInput struct {
+	src              source.Source
+	eventhandler     handler.EventHandler
+	predicates       []predicate.Predicate
+	objectProjection objectProjection
+}
+
+// Watches exposes the lower-level ControllerManagedBy Watches functions through the builder.  Consider using
+// Owns or For instead of Watches directly.
+// Specified predicates are registered only for given source.
+func (blder *Builder) Watches(src source.Source, eventhandler handler.EventHandler, opts ...WatchesOption) *Builder {
+	input := WatchesInput{src: src, eventhandler: eventhandler}
+	for _, opt := range opts {
+		opt.ApplyToWatches(&input)
+	}
+
+	blder.watchesInput = append(blder.watchesInput, input)
+	return blder
+}
+
+// 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.
+// Defaults to the empty list.
+func (blder *Builder) WithEventFilter(p predicate.Predicate) *Builder {
+	blder.globalPredicates = append(blder.globalPredicates, p)
+	return blder
+}
+
+// WithOptions overrides the controller options use in doController. Defaults to empty.
+func (blder *Builder) WithOptions(options controller.Options) *Builder {
+	blder.ctrlOptions = options
+	return blder
+}
+
+// WithLogger overrides the controller options's logger used.
+func (blder *Builder) WithLogger(log logr.Logger) *Builder {
+	blder.ctrlOptions.Log = log
+	return blder
+}
+
+// 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 (blder *Builder) Named(name string) *Builder {
+	blder.name = name
+	return blder
+}
+
+// Complete builds the Application ControllerManagedBy.
+func (blder *Builder) Complete(r reconcile.Reconciler) error {
+	_, err := blder.Build(r)
+	return err
+}
+
+// Build builds the Application ControllerManagedBy and returns the Controller it created.
+func (blder *Builder) Build(r reconcile.Reconciler) (controller.Controller, error) {
+	if r == nil {
+		return nil, fmt.Errorf("must provide a non-nil Reconciler")
+	}
+	if blder.mgr == nil {
+		return nil, fmt.Errorf("must provide a non-nil Manager")
+	}
+	if blder.forInput.err != nil {
+		return nil, blder.forInput.err
+	}
+	// Checking the reconcile type exist or not
+	if blder.forInput.object == nil {
+		return nil, fmt.Errorf("must provide an object for reconciliation")
+	}
+
+	// Set the Config
+	blder.loadRestConfig()
+
+	// Set the ControllerManagedBy
+	if err := blder.doController(r); err != nil {
+		return nil, err
+	}
+
+	// Set the Watch
+	if err := blder.doWatch(); err != nil {
+		return nil, err
+	}
+
+	return blder.ctrl, nil
+}
+
+func (blder *Builder) project(obj client.Object, proj objectProjection) (client.Object, error) {
+	switch proj {
+	case projectAsNormal:
+		return obj, nil
+	case projectAsMetadata:
+		metaObj := &metav1.PartialObjectMetadata{}
+		gvk, err := getGvk(obj, blder.mgr.GetScheme())
+		if err != nil {
+			return nil, fmt.Errorf("unable to determine GVK of %T for a metadata-only watch: %w", obj, err)
+		}
+		metaObj.SetGroupVersionKind(gvk)
+		return metaObj, nil
+	default:
+		panic(fmt.Sprintf("unexpected projection type %v on type %T, should not be possible since this is an internal field", proj, obj))
+	}
+}
+
+func (blder *Builder) doWatch() error {
+	// Reconcile type
+	typeForSrc, err := blder.project(blder.forInput.object, blder.forInput.objectProjection)
+	if err != nil {
+		return err
+	}
+	src := &source.Kind{Type: typeForSrc}
+	hdler := &handler.EnqueueRequestForObject{}
+	allPredicates := append(blder.globalPredicates, blder.forInput.predicates...)
+	if err := blder.ctrl.Watch(src, hdler, allPredicates...); err != nil {
+		return err
+	}
+
+	// Watches the managed types
+	for _, own := range blder.ownsInput {
+		typeForSrc, err := blder.project(own.object, own.objectProjection)
+		if err != nil {
+			return err
+		}
+		src := &source.Kind{Type: typeForSrc}
+		hdler := &handler.EnqueueRequestForOwner{
+			OwnerType:    blder.forInput.object,
+			IsController: true,
+		}
+		allPredicates := append([]predicate.Predicate(nil), blder.globalPredicates...)
+		allPredicates = append(allPredicates, own.predicates...)
+		if err := blder.ctrl.Watch(src, hdler, allPredicates...); err != nil {
+			return err
+		}
+	}
+
+	// Do the watch requests
+	for _, w := range blder.watchesInput {
+		allPredicates := append([]predicate.Predicate(nil), blder.globalPredicates...)
+		allPredicates = append(allPredicates, w.predicates...)
+
+		// If the source of this watch is of type *source.Kind, project it.
+		if srckind, ok := w.src.(*source.Kind); ok {
+			typeForSrc, err := blder.project(srckind.Type, w.objectProjection)
+			if err != nil {
+				return err
+			}
+			srckind.Type = typeForSrc
+		}
+
+		if err := blder.ctrl.Watch(w.src, w.eventhandler, allPredicates...); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (blder *Builder) loadRestConfig() {
+	if blder.config == nil {
+		blder.config = blder.mgr.GetConfig()
+	}
+}
+
+func (blder *Builder) getControllerName(gvk schema.GroupVersionKind) string {
+	if blder.name != "" {
+		return blder.name
+	}
+	return strings.ToLower(gvk.Kind)
+}
+
+func (blder *Builder) doController(r reconcile.Reconciler) error {
+	ctrlOptions := blder.ctrlOptions
+	if ctrlOptions.Reconciler == nil {
+		ctrlOptions.Reconciler = r
+	}
+
+	// Retrieve the GVK from the object we're reconciling
+	// to prepopulate logger information, and to optionally generate a default name.
+	gvk, err := getGvk(blder.forInput.object, blder.mgr.GetScheme())
+	if err != nil {
+		return err
+	}
+
+	// Setup the logger.
+	if ctrlOptions.Log == nil {
+		ctrlOptions.Log = blder.mgr.GetLogger()
+	}
+	ctrlOptions.Log = ctrlOptions.Log.WithValues("reconciler group", gvk.Group, "reconciler kind", gvk.Kind)
+
+	// Build the controller and return.
+	blder.ctrl, err = newController(blder.getControllerName(gvk), blder.mgr, ctrlOptions)
+	return err
+}