Add autoscaler ConfigMap to revision reconciler and create deployment with initial scale

pkg/reconciler/revision/config/store.go

@@ -41,6 +41,7 @@ type Config struct {
 	Network       *network.Config
 	Observability *metrics.ObservabilityConfig
 	Tracing       *pkgtracing.Config
+	Autoscaler    *autoscalerconfig.Config
 }
 
 // FromContext loads the configuration from the context.
@@ -93,5 +94,6 @@ func (s *Store) Load() *Config {
 		Network:       s.UntypedLoad(network.ConfigName).(*network.Config).DeepCopy(),
 		Observability: s.UntypedLoad(metrics.ConfigMapName()).(*metrics.ObservabilityConfig).DeepCopy(),
 		Tracing:       s.UntypedLoad(pkgtracing.ConfigName).(*pkgtracing.Config).DeepCopy(),
+		Autoscaler:    s.UntypedLoad(autoscalerconfig.ConfigName).(*autoscalerconfig.Config).DeepCopy(),
 	}
 }

pkg/reconciler/revision/config/store_test.go

@@ -127,6 +127,13 @@ func TestStoreLoadWithContext(t *testing.T) {
 			t.Error("Unexpected defaults config (-want, +got):", diff)
 		}
 	})
+
+	t.Run("autoscaler", func(t *testing.T) {
+		expected, _ := autoscalerconfig.NewConfigFromConfigMap(autoscalerConfig)
+		if diff := cmp.Diff(expected, config.Autoscaler); diff != "" {
+			t.Error("Unexpected autoscaler config (-want, +got):", diff)
+		}
+	})
 }
 
 func TestStoreImmutableConfig(t *testing.T) {
@@ -146,6 +153,8 @@ func TestStoreImmutableConfig(t *testing.T) {
 	config.Logging.LoggingConfig = "mutated"
 	ccMutated := int64(4)
 	config.Defaults.ContainerConcurrency = ccMutated
+	scaleupMutated := float64(4)
+	config.Autoscaler.MaxScaleUpRate = scaleupMutated
 
 	newConfig := store.Load()
 
@@ -158,4 +167,7 @@ func TestStoreImmutableConfig(t *testing.T) {
 	if newConfig.Defaults.ContainerConcurrency == ccMutated {
 		t.Error("Defaults config is not immutable")
 	}
+	if newConfig.Autoscaler.MaxScaleUpRate == scaleupMutated {
+		t.Error("Autoscaler config is not immutable")
+	}
 }

pkg/reconciler/revision/cruds.go

@@ -43,6 +43,7 @@ func (c *Reconciler) createDeployment(ctx context.Context, rev *v1.Revision) (*a
 		cfgs.Network,
 		cfgs.Observability,
 		cfgs.Deployment,
+		cfgs.Autoscaler,
 	)
 
 	if err != nil {
@@ -63,6 +64,7 @@ func (c *Reconciler) checkAndUpdateDeployment(ctx context.Context, rev *v1.Revis
 		cfgs.Network,
 		cfgs.Observability,
 		cfgs.Deployment,
+		cfgs.Autoscaler,
 	)
 
 	if err != nil {

pkg/reconciler/revision/resources/deploy.go

@@ -26,8 +26,10 @@ import (
 	"knative.dev/pkg/metrics"
 	"knative.dev/pkg/ptr"
 	tracingconfig "knative.dev/pkg/tracing/config"
+	"knative.dev/serving/pkg/apis/autoscaling"
 	"knative.dev/serving/pkg/apis/serving"
 	v1 "knative.dev/serving/pkg/apis/serving/v1"
+	asconfig "knative.dev/serving/pkg/autoscaler/config"
 	"knative.dev/serving/pkg/deployment"
 	"knative.dev/serving/pkg/network"
 	"knative.dev/serving/pkg/queue"
@@ -217,7 +219,9 @@ func buildUserPortEnv(userPort string) corev1.EnvVar {
 
 // MakeDeployment constructs a K8s Deployment resource from a revision.
 func MakeDeployment(rev *v1.Revision,
-	loggingConfig *logging.Config, tracingConfig *tracingconfig.Config, networkConfig *network.Config, observabilityConfig *metrics.ObservabilityConfig, deploymentConfig *deployment.Config) (*appsv1.Deployment, error) {
+	loggingConfig *logging.Config, tracingConfig *tracingconfig.Config, networkConfig *network.Config,
+	observabilityConfig *metrics.ObservabilityConfig, deploymentConfig *deployment.Config,
+	autoscalerConfig *asconfig.Config) (*appsv1.Deployment, error) {
 
 	podTemplateAnnotations := kmeta.FilterMap(rev.GetAnnotations(), func(k string) bool {
 		return k == serving.RevisionLastPinnedAnnotationKey
@@ -228,6 +232,13 @@ func MakeDeployment(rev *v1.Revision,
 		return nil, fmt.Errorf("failed to create PodSpec: %w", err)
 	}
 
+	replicaCount := int(autoscalerConfig.InitialScale)
+	ann, found := rev.ObjectMeta.Annotations[autoscaling.InitialScaleAnnotationKey]
+	if found {
+		// Ignore errors and no error checking because already validated in webhook.
+		replicaCount, _ = strconv.Atoi(ann)
+	}
+
 	return &appsv1.Deployment{
 		ObjectMeta: metav1.ObjectMeta{
 			Name:      names.Deployment(rev),
@@ -240,7 +251,7 @@ func MakeDeployment(rev *v1.Revision,
 			OwnerReferences: []metav1.OwnerReference{*kmeta.NewControllerRef(rev)},
 		},
 		Spec: appsv1.DeploymentSpec{
-			Replicas:                ptr.Int32(1),
+			Replicas:                ptr.Int32(int32(replicaCount)),
 			Selector:                makeSelector(rev),
 			ProgressDeadlineSeconds: ptr.Int32(int32(deploymentConfig.ProgressDeadline.Seconds())),
 			Template: corev1.PodTemplateSpec{

pkg/reconciler/revision/resources/deploy_test.go

@@ -35,8 +35,10 @@ import (
 	"knative.dev/pkg/ptr"
 	"knative.dev/pkg/system"
 	_ "knative.dev/pkg/system/testing"
+	"knative.dev/serving/pkg/apis/autoscaling"
 	"knative.dev/serving/pkg/apis/serving"
 	v1 "knative.dev/serving/pkg/apis/serving/v1"
+	asconfig "knative.dev/serving/pkg/autoscaler/config"
 	"knative.dev/serving/pkg/deployment"
 	"knative.dev/serving/pkg/network"
 
@@ -939,17 +941,18 @@ func TestMakePodSpec(t *testing.T) {
 
 func TestMissingProbeError(t *testing.T) {
 	if _, err := MakeDeployment(revision("bar", "foo"), &logConfig, &traceConfig,
-		&network.Config{}, &obsConfig, &deploymentConfig); err == nil {
+		&network.Config{}, &obsConfig, &deploymentConfig, &asConfig); err == nil {
 		t.Error("expected error from MakeDeployment")
 	}
 }
 
 func TestMakeDeployment(t *testing.T) {
 	tests := []struct {
-		name string
-		rev  *v1.Revision
-		want *appsv1.Deployment
-		dc   deployment.Config
+		name      string
+		rev       *v1.Revision
+		want      *appsv1.Deployment
+		dc        deployment.Config
+		acMutator func(*asconfig.Config)
 	}{{
 		name: "with concurrency=1",
 		rev: revision("bar", "foo",
@@ -1023,19 +1026,65 @@ func TestMakeDeployment(t *testing.T) {
 		want: appsv1deployment(func(deploy *appsv1.Deployment) {
 			deploy.Spec.ProgressDeadlineSeconds = ptr.Int32(42)
 		}),
+	}, {
+		name: "cluster initial scale",
+		acMutator: func(ac *asconfig.Config) {
+			ac.InitialScale = 10
+		},
+		rev: revision("bar", "foo",
+			withoutLabels,
+			withContainers([]corev1.Container{{
+				Name:           servingContainerName,
+				Image:          "ubuntu",
+				ReadinessProbe: withTCPReadinessProbe(12345),
+			}}),
+		),
+		want: appsv1deployment(func(deploy *appsv1.Deployment) {
+			deploy.Spec.Replicas = ptr.Int32(int32(10))
+		}),
+	}, {
+		name: "cluster initial scale override by revision initial scale",
+		acMutator: func(ac *asconfig.Config) {
+			ac.InitialScale = 10
+		},
+		rev: revision("bar", "foo",
+			withoutLabels,
+			withContainers([]corev1.Container{{
+				Name:           servingContainerName,
+				Image:          "ubuntu",
+				ReadinessProbe: withTCPReadinessProbe(12345),
+			}}),
+			func(revision *v1.Revision) {
+				revision.ObjectMeta.Annotations = map[string]string{autoscaling.InitialScaleAnnotationKey: "20"}
+			},
+		),
+		want: appsv1deployment(func(deploy *appsv1.Deployment) {
+			deploy.Spec.Replicas = ptr.Int32(int32(20))
+			deploy.Spec.Template.ObjectMeta.Annotations = map[string]string{autoscaling.InitialScaleAnnotationKey: "20"}
+			deploy.ObjectMeta.Annotations = map[string]string{autoscaling.InitialScaleAnnotationKey: "20"}
+		}),
 	}}
 
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
+			ac := &asconfig.Config{
+				InitialScale:          1,
+				AllowZeroInitialScale: false,
+			}
+			if test.acMutator != nil {
+				test.acMutator(ac)
+			}
 			// Tested above so that we can rely on it here for brevity.
 			podSpec, err := makePodSpec(test.rev, &logConfig, &traceConfig,
 				&obsConfig, &deploymentConfig)
 			if err != nil {
 				t.Fatal("makePodSpec returned error:", err)
 			}
-			test.want.Spec.Template.Spec = *podSpec
+			if test.want != nil {
+				test.want.Spec.Template.Spec = *podSpec
+			}
 			got, err := MakeDeployment(test.rev, &logConfig, &traceConfig,
-				&network.Config{}, &obsConfig, &test.dc)
+				&network.Config{}, &obsConfig, &test.dc, ac)
 			if err != nil {
 				t.Fatal("got unexpected error:", err)
 			}

pkg/reconciler/revision/resources/queue_test.go

@@ -42,6 +42,7 @@ import (
 	tracingconfig "knative.dev/pkg/tracing/config"
 	"knative.dev/serving/pkg/apis/serving"
 	v1 "knative.dev/serving/pkg/apis/serving/v1"
+	asconfig "knative.dev/serving/pkg/autoscaler/config"
 	"knative.dev/serving/pkg/deployment"
 	"knative.dev/serving/pkg/network"
 )
@@ -66,6 +67,10 @@ var (
 	traceConfig      tracingconfig.Config
 	obsConfig        metrics.ObservabilityConfig
 	deploymentConfig deployment.Config
+	asConfig         = asconfig.Config{
+		InitialScale:          1,
+		AllowZeroInitialScale: false,
+	}
 )
 
 const testProbeJSONTemplate = `{"tcpSocket":{"port":%d,"host":"127.0.0.1"}}`

pkg/reconciler/revision/table_test.go

@@ -39,6 +39,7 @@ import (
 	asv1a1 "knative.dev/serving/pkg/apis/autoscaling/v1alpha1"
 	defaultconfig "knative.dev/serving/pkg/apis/config"
 	v1 "knative.dev/serving/pkg/apis/serving/v1"
+	asconfig "knative.dev/serving/pkg/autoscaler/config"
 	servingclient "knative.dev/serving/pkg/client/injection/client"
 	revisionreconciler "knative.dev/serving/pkg/client/injection/reconciler/serving/v1/revision"
 	"knative.dev/serving/pkg/reconciler/revision/config"
@@ -716,7 +717,7 @@ func deploy(t *testing.T, namespace, name string, opts ...interface{}) *appsv1.D
 	// before calling MakeDeployment within Reconcile.
 	rev.SetDefaults(context.Background())
 	deployment, err := resources.MakeDeployment(rev, cfg.Logging, cfg.Tracing, cfg.Network,
-		cfg.Observability, cfg.Deployment)
+		cfg.Observability, cfg.Deployment, cfg.Autoscaler)
 	if err != nil {
 		t.Fatal("failed to create deployment")
 	}
@@ -779,5 +780,9 @@ func ReconcilerTestConfig() *config.Config {
 		Logging:  &logging.Config{},
 		Tracing:  &tracingconfig.Config{},
 		Defaults: &defaultconfig.Defaults{},
+		Autoscaler: &asconfig.Config{
+			InitialScale:          1,
+			AllowZeroInitialScale: false,
+		},
 	}
 }