Have the ClusterBuildTemplate controller instantiate Image resources.

Unlike the BuildTemplate controller, which colocates the Image references,
this places the Image resources (which are namespaced) in the knative-build
namespace.

pkg/reconciler/buildtemplate/buildtemplate.go

@@ -153,21 +153,8 @@ func (c *Reconciler) reconcileImageCaches(ctx context.Context, bt *v1alpha1.Buil
 	}
 
 	// Make sure we have all of the desired caching resources.
-	if missing := allCached(ics, eics); len(missing) > 0 {
-		grp, _ := errgroup.WithContext(ctx)
-
-		for _, m := range missing {
-			m := m
-			grp.Go(func() error {
-				_, err := c.cachingclientset.CachingV1alpha1().Images(m.Namespace).Create(&m)
-				return err
-			})
-		}
-
-		// Wait for the creates to complete.
-		if err := grp.Wait(); err != nil {
-			return err
-		}
+	if err := CreateMissingImageCaches(ctx, c.cachingclientset, ics, eics); err != nil {
+		return err
 	}
 
 	// Delete any Image caches relevant to older versions of this resource.
@@ -178,7 +165,7 @@ func (c *Reconciler) reconcileImageCaches(ctx context.Context, bt *v1alpha1.Buil
 	)
 }
 
-func allCached(desired []caching.Image, observed []*caching.Image) (missing []caching.Image) {
+func missingImageCaches(desired []caching.Image, observed []*caching.Image) (missing []caching.Image) {
 	for _, d := range desired {
 		found := false
 		for _, o := range observed {
@@ -193,3 +180,23 @@ func allCached(desired []caching.Image, observed []*caching.Image) (missing []ca
 	}
 	return missing
 }
+
+func CreateMissingImageCaches(ctx context.Context, client cachingclientset.Interface,
+	desired []caching.Image, observed []*caching.Image) error {
+	missing := missingImageCaches(desired, observed)
+	if len(missing) == 0 {
+		return nil
+	}
+
+	grp, _ := errgroup.WithContext(ctx)
+	for _, m := range missing {
+		m := m
+		grp.Go(func() error {
+			_, err := client.CachingV1alpha1().Images(m.Namespace).Create(&m)
+			return err
+		})
+	}
+
+	// Wait for the creates to complete.
+	return grp.Wait()
+}

pkg/reconciler/buildtemplate/resources/imagecache.go

@@ -30,7 +30,7 @@ import (
 
 // Note: namespace is passed separately because this may be used for
 // cluster-scoped stuff as well.
-func makeImageCachesFromSpec(
+func MakeImageCachesFromSpec(
 	namespace string,
 	bt names.ImageCacheable,
 ) []caching.Image {
@@ -67,5 +67,5 @@ func makeImageCachesFromSpec(
 }
 
 func MakeImageCaches(bt *v1alpha1.BuildTemplate) []caching.Image {
-	return makeImageCachesFromSpec(bt.Namespace, bt)
+	return MakeImageCachesFromSpec(bt.Namespace, bt)
 }

pkg/reconciler/clusterbuildtemplate/clusterbuildtemplate.go

@@ -21,18 +21,24 @@ import (
 
 	"go.uber.org/zap"
 	"k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/kubernetes/scheme"
 	"k8s.io/client-go/tools/cache"
 
 	"github.com/knative/pkg/controller"
+	"github.com/knative/pkg/kmeta"
 	"github.com/knative/pkg/logging"
 	"github.com/knative/pkg/logging/logkey"
 
+	"github.com/knative/build/pkg/apis/build/v1alpha1"
 	clientset "github.com/knative/build/pkg/client/clientset/versioned"
 	buildscheme "github.com/knative/build/pkg/client/clientset/versioned/scheme"
 	informers "github.com/knative/build/pkg/client/informers/externalversions/build/v1alpha1"
 	listers "github.com/knative/build/pkg/client/listers/build/v1alpha1"
+	"github.com/knative/build/pkg/reconciler/buildtemplate"
+	"github.com/knative/build/pkg/reconciler/clusterbuildtemplate/resources"
+	"github.com/knative/build/pkg/system"
 	cachingclientset "github.com/knative/caching/pkg/client/clientset/versioned"
 	cachinginformers "github.com/knative/caching/pkg/client/informers/externalversions/caching/v1alpha1"
 	cachinglisters "github.com/knative/caching/pkg/client/listers/caching/v1alpha1"
@@ -50,7 +56,7 @@ type Reconciler struct {
 	cachingclientset cachingclientset.Interface
 
 	clusterBuildTemplatesLister listers.ClusterBuildTemplateLister
-	imageLister                 cachinglisters.ImageLister
+	imagesLister                cachinglisters.ImageLister
 
 	// Sugared logger is easier to use but is not as performant as the
 	// raw logger. In performance critical paths, call logger.Desugar()
@@ -87,7 +93,7 @@ func NewController(
 		buildclientset:              buildclientset,
 		cachingclientset:            cachingclientset,
 		clusterBuildTemplatesLister: clusterBuildTemplateInformer.Lister(),
-		imageLister:                 imageInformer.Lister(),
+		imagesLister:                imageInformer.Lister(),
 		Logger:                      logger,
 	}
 	impl := controller.NewImpl(r, logger, "ClusterBuildTemplates")
@@ -99,6 +105,14 @@ func NewController(
 		UpdateFunc: controller.PassNew(impl.Enqueue),
 	})
 
+	imageInformer.Informer().AddEventHandler(cache.FilteringResourceEventHandler{
+		FilterFunc: controller.Filter(v1alpha1.SchemeGroupVersion.WithKind("ClusterBuildTemplate")),
+		Handler: cache.ResourceEventHandlerFuncs{
+			AddFunc:    impl.EnqueueControllerOf,
+			UpdateFunc: controller.PassNew(impl.EnqueueControllerOf),
+		},
+	})
+
 	return impl
 }
 
@@ -107,14 +121,39 @@ func (c *Reconciler) Reconcile(ctx context.Context, key string) error {
 	logger := logging.FromContext(ctx)
 
 	// Get the ClusterBuildTemplate resource with this key
-	if _, err := c.clusterBuildTemplatesLister.Get(key); errors.IsNotFound(err) {
+	cbt, err := c.clusterBuildTemplatesLister.Get(key)
+	if errors.IsNotFound(err) {
 		// The ClusterBuildTemplate resource may no longer exist, in which case we stop processing.
 		logger.Errorf("clusterbuildtemplate %q in work queue no longer exists", key)
 		return nil
 	} else if err != nil {
 		return err
 	}
 
-	// TODO: Meaningful reconciliation.
+	if err := c.reconcileImageCaches(ctx, cbt); err != nil {
+		return err
+	}
+
 	return nil
 }
+
+func (c *Reconciler) reconcileImageCaches(ctx context.Context, cbt *v1alpha1.ClusterBuildTemplate) error {
+	ics := resources.MakeImageCaches(cbt)
+
+	eics, err := c.imagesLister.Images(system.Namespace).List(kmeta.MakeVersionLabelSelector(cbt))
+	if err != nil {
+		return err
+	}
+
+	// Make sure we have all of the desired caching resources.
+	if err := buildtemplate.CreateMissingImageCaches(ctx, c.cachingclientset, ics, eics); err != nil {
+		return err
+	}
+
+	// Delete any Image caches relevant to older versions of this resource.
+	propPolicy := metav1.DeletePropagationForeground
+	return c.cachingclientset.CachingV1alpha1().Images(system.Namespace).DeleteCollection(
+		&metav1.DeleteOptions{PropagationPolicy: &propPolicy},
+		metav1.ListOptions{LabelSelector: kmeta.MakeOldVersionLabelSelector(cbt).String()},
+	)
+}

pkg/reconciler/clusterbuildtemplate/resources/imagecache.go

@@ -0,0 +1,28 @@
+/*
+Copyright 2018 The Knative 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 resources
+
+import (
+	"github.com/knative/build/pkg/apis/build/v1alpha1"
+	buildtemplateresources "github.com/knative/build/pkg/reconciler/buildtemplate/resources"
+	"github.com/knative/build/pkg/system"
+	caching "github.com/knative/caching/pkg/apis/caching/v1alpha1"
+)
+
+func MakeImageCaches(bt *v1alpha1.ClusterBuildTemplate) []caching.Image {
+	return buildtemplateresources.MakeImageCachesFromSpec(system.Namespace, bt)
+}