Add the storageversion.Manager interface

The interface exposes methods to record storage versions in
ResourceInfo, to update StorageVersions, and to check if storageVersion
updated have completed.

staging/src/k8s.io/apiserver/pkg/storageversion/BUILD

@@ -0,0 +1,39 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["updater.go"],
+    importmap = "k8s.io/kubernetes/vendor/k8s.io/apiserver/pkg/storageversion",
+    importpath = "k8s.io/apiserver/pkg/storageversion",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//staging/src/k8s.io/apimachinery/pkg/api/errors:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
+        "//staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/v1alpha1:go_default_library",
+        "//vendor/k8s.io/klog:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["updater_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//staging/src/k8s.io/apiserver/pkg/apis/apiserverinternal/v1alpha1:go_default_library",
+        "//vendor/github.com/google/go-cmp/cmp:go_default_library",
+    ],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+    visibility = ["//visibility:public"],
+)

staging/src/k8s.io/apiserver/pkg/storageversion/manager.go

@@ -0,0 +1,194 @@
+/*
+Copyright 2020 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 storageversion
+
+import (
+	"sync"
+	"sync/atomic"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	apiserverclientset "k8s.io/apiserver/pkg/client/clientset_generated/clientset"
+	"k8s.io/client-go/rest"
+	_ "k8s.io/component-base/metrics/prometheus/workqueue" // for workqueue metric registration
+	"k8s.io/klog"
+)
+
+// ResourceInfo contains the information to register the resource to the
+// storage version API.
+type ResourceInfo struct {
+	Resource metav1.APIResource
+	// We use a standalone Group instead of reusing the Resource.Group
+	// because Resource.Group is often omitted, see the comment on
+	// Resource.Group for why it's omitted.
+	Group                    string
+	EncodingVersion          string
+	DecodableVersions        []string
+	EquivalentResourceMapper runtime.EquivalentResourceRegistry
+}
+
+// Manager records the resources whose StorageVersions need updates, and provides a method to update those StorageVersions.
+type Manager interface {
+	// AddResourceInfo adds ResourceInfo to the manager.
+	AddResourceInfo(resources ...*ResourceInfo)
+	// RemoveResourceInfo removes ResourceInfo from the manager.
+	RemoveResourceInfo(r *ResourceInfo)
+	// UpdatesPending returns if the StorageVersion of a resource is still wait to be updated.
+	UpdatesPending(group, resource string) bool
+
+	// UpdateStorageVersions updates the StorageVersions.
+	UpdateStorageVersions(loopbackClientConfig *rest.Config, apiserverID string)
+	// Completed returns if updating StorageVersions has completed.
+	Completed() bool
+}
+
+var _ Manager = &DefaultManager{}
+
+// NewDefaultManager creates a new DefaultManager.
+func NewDefaultManager() *DefaultManager {
+	s := &DefaultManager{}
+	s.completed.Store(false)
+	s.groupResources = make(map[string]map[string]struct{})
+	s.resources = make(map[*ResourceInfo]struct{})
+	return s
+}
+
+// AddResourceInfo adds ResourceInfo to the manager.
+// This is not thread-safe. It is expected to be called when the apiserver is installing the endpoints, which is done serially.
+func (s *DefaultManager) AddResourceInfo(resources ...*ResourceInfo) {
+	for _, r := range resources {
+		s.resources[r] = struct{}{}
+		s.addGroupResourceFor(r)
+	}
+}
+
+func (s *DefaultManager) addGroupResourceFor(r *ResourceInfo) {
+	gvrs := r.EquivalentResourceMapper.EquivalentResourcesFor(schema.GroupVersionResource{
+		Group:    r.Group,
+		Resource: r.Resource.Name,
+	}, "")
+	for _, gvr := range gvrs {
+		s.addGroupResource(gvr.Group, gvr.Resource)
+	}
+}
+
+func (s *DefaultManager) addGroupResource(group, resource string) {
+	if _, ok := s.groupResources[group]; !ok {
+		s.groupResources[group] = make(map[string]struct{})
+	}
+	s.groupResources[group][resource] = struct{}{}
+}
+
+// RemoveResourceInfo removes ResourceInfo from the manager.
+// It is not safe to call this function concurrently with AddResourceInfo.
+func (s *DefaultManager) RemoveResourceInfo(r *ResourceInfo) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	delete(s.resources, r)
+	s.removeGroupResourceFor(r)
+}
+
+func (s *DefaultManager) removeGroupResourceFor(r *ResourceInfo) {
+	gvrs := r.EquivalentResourceMapper.EquivalentResourcesFor(schema.GroupVersionResource{
+		Group:    r.Group,
+		Resource: r.Resource.Name,
+	}, "")
+	for _, gvr := range gvrs {
+		s.removeGroupResource(gvr.Group, gvr.Version)
+	}
+}
+
+func (s *DefaultManager) removeGroupResource(group, resource string) {
+	if _, ok := s.groupResources[group]; !ok {
+		return
+	}
+	delete(s.groupResources[group], resource)
+	if len(s.groupResources[group]) == 0 {
+		delete(s.groupResources, group)
+	}
+}
+
+// UpdatesPending returns if the StorageVersion of a resource is still wait to be updated.
+func (s *DefaultManager) UpdatesPending(group, resource string) bool {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+	if _, ok := s.groupResources[group]; !ok {
+		return false
+	}
+	_, ok := s.groupResources[group][resource]
+	return ok
+}
+
+// DefaultManager indicates if the aggregator, kube-apiserver, and the
+// apiextensions-apiserver have completed reporting their storage versions.
+type DefaultManager struct {
+	completed atomic.Value
+
+	mu             sync.RWMutex
+	resources      map[*ResourceInfo]struct{}
+	groupResources map[string]map[string]struct{}
+}
+
+// setComplete marks the completion of updating StorageVersions. No write requests need to be blocked anymore.
+func (s *DefaultManager) setComplete() {
+	s.completed.Store(true)
+}
+
+// Completed returns if updating StorageVersions has completed.
+func (s *DefaultManager) Completed() bool {
+	return s.completed.Load().(bool)
+}
+
+func decodableVersions(e runtime.EquivalentResourceRegistry, group string, resource string) []string {
+	var versions []string
+	decodingGVRs := e.EquivalentResourcesFor(schema.GroupVersionResource{
+		Group:    group,
+		Resource: resource,
+	}, "")
+	for _, v := range decodingGVRs {
+		versions = append(versions, v.GroupVersion().String())
+	}
+	return versions
+}
+
+// UpdateStorageVersions updates the StorageVersions. If the updates are
+// successful, following calls to Completed() returns true.
+func (s *DefaultManager) UpdateStorageVersions(loopbackClientConfig *rest.Config, serverID string) {
+	cfg := rest.AddUserAgent(loopbackClientConfig, "system:kube-apiserver")
+	clientset, err := apiserverclientset.NewForConfig(cfg)
+	if err != nil {
+		klog.Fatalf("failed to get clientset: %v", err)
+		return
+	}
+	sc := clientset.InternalV1alpha1().StorageVersions()
+
+	s.mu.RLock()
+	resources := s.resources
+	s.mu.RUnlock()
+	for r := range resources {
+		r.DecodableVersions = decodableVersions(r.EquivalentResourceMapper, r.Group, r.Resource.Name)
+		if err := updateStorageVersionFor(sc, serverID, r.Group+"."+r.Resource.Name, r.EncodingVersion, r.DecodableVersions); err != nil {
+			klog.Fatalf("failed to update storage version for %v", r.Resource.Name)
+			return
+		}
+		klog.V(2).Infof("successfully updated storage version for %v", r.Resource.Name)
+		s.RemoveResourceInfo(r)
+	}
+	klog.V(2).Infof("storage version updates complete")
+	s.setComplete()
+}

staging/src/k8s.io/apiserver/pkg/storageversion/updater.go

@@ -0,0 +1,116 @@
+/*
+Copyright 2019 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 storageversion
+
+import (
+	"context"
+	"time"
+
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apiserver/pkg/apis/apiserverinternal/v1alpha1"
+	"k8s.io/klog"
+)
+
+// Client has the methods required to update the storage version.
+type Client interface {
+	Create(context.Context, *v1alpha1.StorageVersion, metav1.CreateOptions) (*v1alpha1.StorageVersion, error)
+	Update(context.Context, *v1alpha1.StorageVersion, metav1.UpdateOptions) (*v1alpha1.StorageVersion, error)
+	Get(context.Context, string, metav1.GetOptions) (*v1alpha1.StorageVersion, error)
+}
+
+func setAgreedEncodingVersion(sv *v1alpha1.StorageVersion) {
+	if len(sv.Status.ServerStorageVersions) == 0 {
+		return
+	}
+	firstVersion := sv.Status.ServerStorageVersions[0].EncodingVersion
+	agreed := true
+	for _, ssv := range sv.Status.ServerStorageVersions {
+		if ssv.EncodingVersion != firstVersion {
+			agreed = false
+		}
+	}
+	if agreed {
+		sv.Status.AgreedEncodingVersion = &firstVersion
+	} else {
+		sv.Status.AgreedEncodingVersion = nil
+	}
+}
+
+// updateStorageVersionFor updates the storage version object for the resource.
+// resource is of the format "<group>.<resource>".
+// TODO: split the resource parameter to two.
+func updateStorageVersionFor(c Client, apiserverID string, resource string, encodingVersion string, decodableVersions []string) error {
+	retries := 3
+	var retry int
+	var err error
+	for retry < retries {
+		err = singleUpdate(c, apiserverID, resource, encodingVersion, decodableVersions)
+		if err == nil {
+			return nil
+		}
+		if apierrors.IsAlreadyExists(err) || apierrors.IsConflict(err) {
+			time.Sleep(1 * time.Second)
+			continue
+		}
+		if err != nil {
+			klog.Errorf("retry %d, failed to update storage version for %s: %v", retry, resource, err)
+			retry++
+			time.Sleep(1 * time.Second)
+		}
+	}
+	return err
+}
+
+func singleUpdate(c Client, apiserverID, resource, encodingVersion string, decodableVersions []string) error {
+	shouldCreate := false
+	sv, err := c.Get(context.TODO(), resource, metav1.GetOptions{})
+	if err != nil && !apierrors.IsNotFound(err) {
+		return err
+	}
+	if err != nil && apierrors.IsNotFound(err) {
+		shouldCreate = true
+		sv = &v1alpha1.StorageVersion{}
+		sv.ObjectMeta.Name = resource
+	}
+	localUpdateStorageVersion(sv, apiserverID, encodingVersion, decodableVersions)
+	if shouldCreate {
+		_, err := c.Create(context.TODO(), sv, metav1.CreateOptions{})
+		return err
+	}
+	_, err = c.Update(context.TODO(), sv, metav1.UpdateOptions{})
+	return err
+}
+
+func localUpdateStorageVersion(sv *v1alpha1.StorageVersion, apiserverID, encodingVersion string, decodableVersions []string) {
+	newSSV := v1alpha1.ServerStorageVersion{
+		APIServerID:       apiserverID,
+		EncodingVersion:   encodingVersion,
+		DecodableVersions: decodableVersions,
+	}
+	foundSSV := false
+	for i, ssv := range sv.Status.ServerStorageVersions {
+		if ssv.APIServerID == apiserverID {
+			sv.Status.ServerStorageVersions[i] = newSSV
+			foundSSV = true
+		}
+	}
+	if !foundSSV {
+		sv.Status.ServerStorageVersions = append(sv.Status.ServerStorageVersions, newSSV)
+	}
+	setAgreedEncodingVersion(sv)
+}