Enable emptyDir volumes for Knative Services

.github/workflows/kind-e2e.yaml

@@ -314,9 +314,6 @@ jobs:
         knative_setup
 
         # Run the tests tagged as e2e on the KinD cluster.
-        # TODO: Remove feature toogle when emptyDir is enabled by default
-        toggle_feature kubernetes.podspec-volumes-emptydir Enabled
-
         echo "SYSTEM_NAMESPACE=$SYSTEM_NAMESPACE" >> $GITHUB_ENV
         echo "GATEWAY_OVERRIDE=$GATEWAY_OVERRIDE" >> $GITHUB_ENV
         echo "GATEWAY_NAMESPACE_OVERRIDE=$GATEWAY_NAMESPACE_OVERRIDE" >> $GITHUB_ENV

config/core/configmaps/features.yaml

@@ -22,7 +22,7 @@ metadata:
     app.kubernetes.io/component: controller
     app.kubernetes.io/version: devel
   annotations:
-    knative.dev/example-checksum: "4d5feafc"
+    knative.dev/example-checksum: "b0b9573d"
 data:
   _example: |-
     ################################
@@ -160,7 +160,7 @@ data:
     # Controls whether volume support for EmptyDir is enabled or not.
     # 1. Enabled: enabling EmptyDir volume support
     # 2. Disabled: disabling EmptyDir volume support
-    kubernetes.podspec-volumes-emptydir: "disabled"
+    kubernetes.podspec-volumes-emptydir: "enabled"
 
     # Controls whether init containers support is enabled or not.
     # 1. Enabled: enabling init containers support

pkg/apis/config/features.go

@@ -63,7 +63,7 @@ func defaultFeaturesConfig() *Features {
 		PodSpecSchedulerName:             Disabled,
 		ContainerSpecAddCapabilities:     Disabled,
 		PodSpecTolerations:               Disabled,
-		PodSpecVolumesEmptyDir:           Disabled,
+		PodSpecVolumesEmptyDir:           Enabled,
 		PodSpecPersistentVolumeClaim:     Disabled,
 		PodSpecPersistentVolumeWrite:     Disabled,
 		QueueProxyMountPodInfo:           Disabled,

pkg/apis/serving/k8s_validation_test.go

@@ -2316,7 +2316,7 @@ func TestVolumeValidation(t *testing.T) {
 		v: corev1.Volume{
 			Name: "foo",
 		},
-		want: apis.ErrMissingOneOf("secret", "configMap", "projected"),
+		want: apis.ErrMissingOneOf("secret", "configMap", "projected", "emptyDir"),
 	}, {
 		name: "secret volume",
 		v: corev1.Volume{
@@ -2395,7 +2395,7 @@ func TestVolumeValidation(t *testing.T) {
 		v: corev1.Volume{
 			Name: "foo",
 		},
-		want: apis.ErrMissingOneOf("secret", "configMap", "projected"),
+		want: apis.ErrMissingOneOf("secret", "configMap", "projected", "emptyDir"),
 	}, {
 		name: "multiple volume source",
 		v: corev1.Volume{

test/e2e-tests.sh

@@ -75,14 +75,12 @@ if (( SHORT )); then
 fi
 
 toggle_feature autocreateClusterDomainClaims true config-network || fail_test
-toggle_feature kubernetes.podspec-volumes-emptydir Enabled
 go_test_e2e -timeout=30m \
   ./test/conformance/api/... \
   ./test/conformance/runtime/... \
   ./test/e2e \
   ${parallelism} \
   ${TEST_OPTIONS} || failed=1
-toggle_feature kubernetes.podspec-volumes-emptydir Disabled
 toggle_feature autocreateClusterDomainClaims false config-network || fail_test
 
 toggle_feature tag-header-based-routing Enabled
@@ -113,13 +111,11 @@ kubectl replace cm "config-gc" -n ${SYSTEM_NAMESPACE} -f ${TMP_DIR}/config-gc.ya
 # Run HPA tests
 go_test_e2e -timeout=30m -tags=hpa ./test/e2e ${TEST_OPTIONS} || failed=1
 
-# Run emptyDir, initContainers tests with alpha enabled avoiding any issues with the testing options guard above
+# Run initContainers tests with alpha enabled avoiding any issues with the testing options guard above
 # InitContainers test uses emptyDir.
-toggle_feature kubernetes.podspec-volumes-emptydir Enabled
 toggle_feature kubernetes.podspec-init-containers Enabled
 go_test_e2e -timeout=2m ./test/e2e/initcontainers ${TEST_OPTIONS} || failed=1
 toggle_feature kubernetes.podspec-init-containers Disabled
-toggle_feature kubernetes.podspec-volumes-emptydir Disabled
 
 # RUN PVC tests with default storage class.
 toggle_feature kubernetes.podspec-persistent-volume-claim Enabled

test/e2e/empty_dir_test.go

@@ -0,0 +1,73 @@
+//go:build e2e
+
+/*
+Copyright 2022 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 e2e
+
+import (
+	"context"
+	"testing"
+
+	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/resource"
+	pkgTest "knative.dev/pkg/test"
+	"knative.dev/pkg/test/spoof"
+	. "knative.dev/serving/pkg/testing/v1"
+	"knative.dev/serving/test"
+	v1test "knative.dev/serving/test/v1"
+)
+
+// TestEmptyDir ensure emptyDir volume support works
+func TestEmptyDir(t *testing.T) {
+	t.Parallel()
+	clients := test.Setup(t)
+
+	names := test.ResourceNames{
+		Service: test.ObjectNameForTest(t),
+		Image:   test.Volumes,
+	}
+
+	test.EnsureTearDown(t, clients, &names)
+
+	t.Log("Creating a new Service")
+
+	quantity := resource.MustParse("100M")
+	withVolume := WithVolume("data", "/data", corev1.VolumeSource{
+		EmptyDir: &corev1.EmptyDirVolumeSource{
+			SizeLimit: &quantity,
+		},
+	})
+
+	resources, err := v1test.CreateServiceReady(t, clients, &names, withVolume)
+	if err != nil {
+		t.Fatalf("Failed to create initial Service: %v: %v", names.Service, err)
+	}
+
+	url := resources.Route.Status.URL.URL()
+	if _, err := pkgTest.CheckEndpointState(
+		context.Background(),
+		clients.KubeClient,
+		t.Logf,
+		url,
+		spoof.MatchesAllOf(spoof.IsStatusOK, spoof.MatchesBody(test.EmptyDirText)),
+		"EmptyDir Text",
+		test.ServingFlags.ResolvableDomain,
+		test.AddRootCAtoTransport(context.Background(), t.Logf, clients, test.ServingFlags.HTTPS),
+	); err != nil {
+		t.Fatalf("The endpoint %s for Route %s didn't serve the expected text %q: %v", url, names.Route, test.EmptyDirText, err)
+	}
+}