Ensure storage version is understood by prior releases

test/integration/etcd/data.go

@@ -767,3 +767,7 @@ func gvr(g, v, r string) schema.GroupVersionResource {
 func gvkP(g, v, k string) *schema.GroupVersionKind {
 	return &schema.GroupVersionKind{Group: g, Version: v, Kind: k}
 }
+
+func gvk(g, v, k string) schema.GroupVersionKind {
+	return schema.GroupVersionKind{Group: g, Version: v, Kind: k}
+}

test/integration/etcd/etcd_storage_path_test.go

@@ -20,6 +20,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"path/filepath"
 	"reflect"
 	"strings"
 	"testing"
@@ -45,6 +46,25 @@ var kindWhiteList = sets.NewString()
 // namespace used for all tests, do not change this
 const testNamespace = "etcdstoragepathtestnamespace"
 
+// allowMissingTestdataFixtures contains the kinds expected to be missing serialization fixtures API testdata directory.
+// this should only contain custom resources and built-in types with open issues tracking adding serialization fixtures.
+// Do not add new built-in types to this list, add them to k8s.io/api/roundtrip_test.go instead.
+var allowMissingTestdataFixtures = map[schema.GroupVersionKind]bool{
+	// TODO(https://github.com/kubernetes/kubernetes/issues/79027)
+	gvk("apiregistration.k8s.io", "v1", "APIService"):     true,
+	gvk("apiregistration.k8s.io", "v1beta", "APIService"): true,
+
+	// TODO(https://github.com/kubernetes/kubernetes/issues/79026)
+	gvk("apiextensions.k8s.io", "v1beta1", "CustomResourceDefinition"): true,
+	gvk("apiextensions.k8s.io", "v1", "CustomResourceDefinition"):      true,
+
+	// Custom resources are not expected to have serialization fixtures in k8s.io/api
+	gvk("awesome.bears.com", "v1", "Panda"):    true,
+	gvk("cr.bar.com", "v1", "Foo"):             true,
+	gvk("random.numbers.com", "v1", "Integer"): true,
+	gvk("custom.fancy.com", "v2", "Pant"):      true,
+}
+
 // TestEtcdStoragePath tests to make sure that all objects are stored in an expected location in etcd.
 // It will start failing when a new type is added to ensure that all future types are added to this test.
 // It will also fail when a type gets moved to a different location. Be very careful in this situation because
@@ -139,6 +159,40 @@ func TestEtcdStoragePath(t *testing.T) {
 				expectedGVK = *testData.ExpectedGVK
 			}
 
+			// if previous releases had a non-alpha version of this group/kind, make sure the storage version is understood by a previous release
+			fixtureFilenameGroup := expectedGVK.Group
+			if fixtureFilenameGroup == "" {
+				fixtureFilenameGroup = "core"
+			}
+			// find all versions of this group/kind in all versions of the serialization fixture testdata
+			previousReleaseGroupKindFiles, err := filepath.Glob("../../../staging/src/k8s.io/api/testdata/*/" + fixtureFilenameGroup + ".*." + expectedGVK.Kind + ".yaml")
+			if err != nil {
+				t.Error(err)
+			}
+			if len(previousReleaseGroupKindFiles) == 0 && !allowMissingTestdataFixtures[expectedGVK] {
+				// We should at least find the HEAD fixtures
+				t.Errorf("No testdata serialization files found for %#v, cannot determine if previous releases could read this group/kind. Add this group-version to k8s.io/api/roundtrip_test.go", expectedGVK)
+			}
+			// find non-alpha versions of this group/kind understood by previous releases
+			previousNonAlphaVersions := sets.NewString()
+			for _, previousReleaseGroupKindFile := range previousReleaseGroupKindFiles {
+				if serverVersion := filepath.Base(filepath.Dir(previousReleaseGroupKindFile)); serverVersion == "HEAD" {
+					continue
+				}
+				parts := strings.Split(filepath.Base(previousReleaseGroupKindFile), ".")
+				version := parts[len(parts)-3]
+				if !strings.Contains(version, "alpha") {
+					previousNonAlphaVersions.Insert(version)
+				}
+			}
+			if len(previousNonAlphaVersions) > 0 && !previousNonAlphaVersions.Has(expectedGVK.Version) {
+				t.Errorf("Previous releases understand non-alpha versions %q, but do not understand the expected current storage version %q. "+
+					"This means a current server will store data in etcd that is not understood by a previous version.",
+					previousNonAlphaVersions.List(),
+					expectedGVK.Version,
+				)
+			}
+
 			actualGVK := output.getGVK()
 			if actualGVK != expectedGVK {
 				t.Errorf("GVK for %s does not match, expected %s got %s", kind, expectedGVK, actualGVK)
@@ -181,8 +235,10 @@ func TestEtcdStoragePath(t *testing.T) {
 	}
 }
 
+var debug = false
+
 func dumpEtcdKVOnFailure(t *testing.T, kvClient clientv3.KV) {
-	if t.Failed() {
+	if t.Failed() && debug {
 		response, err := kvClient.Get(context.Background(), "/", clientv3.WithPrefix())
 		if err != nil {
 			t.Fatal(err)

test/integration/etcd/server.go

@@ -122,6 +122,9 @@ func StartRealMasterOrDie(t *testing.T, configFuncs ...func(*options.ServerRunOp
 	kubeClientConfig.QPS = 99999
 	kubeClientConfig.Burst = 9999
 
+	// we make requests to all resources, don't log warnings about deprecated ones
+	restclient.SetDefaultWarningHandler(restclient.NoWarnings{})
+
 	kubeClient := clientset.NewForConfigOrDie(kubeClientConfig)
 
 	go func() {