support workspace resource quota

Signed-off-by: hongming <talonwan@yunify.com>

kube/plugin/pkg/admission/resourcequota/resource_access.go

@@ -0,0 +1,155 @@
+/*
+Copyright 2016 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 resourcequota
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/hashicorp/golang-lru"
+
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/labels"
+	"k8s.io/apiserver/pkg/storage/etcd3"
+	"k8s.io/client-go/kubernetes"
+	corev1listers "k8s.io/client-go/listers/core/v1"
+)
+
+// QuotaAccessor abstracts the get/set logic from the rest of the Evaluator.  This could be a test stub, a straight passthrough,
+// or most commonly a series of deconflicting caches.
+type QuotaAccessor interface {
+	// UpdateQuotaStatus is called to persist final status.  This method should write to persistent storage.
+	// An error indicates that write didn't complete successfully.
+	UpdateQuotaStatus(newQuota *corev1.ResourceQuota) error
+
+	// GetQuotas gets all possible quotas for a given namespace
+	GetQuotas(namespace string) ([]corev1.ResourceQuota, error)
+}
+
+type quotaAccessor struct {
+	client kubernetes.Interface
+
+	// lister can list/get quota objects from a shared informer's cache
+	lister corev1listers.ResourceQuotaLister
+
+	// liveLookups holds the last few live lookups we've done to help ammortize cost on repeated lookup failures.
+	// This lets us handle the case of latent caches, by looking up actual results for a namespace on cache miss/no results.
+	// We track the lookup result here so that for repeated requests, we don't look it up very often.
+	liveLookupCache *lru.Cache
+	liveTTL         time.Duration
+	// updatedQuotas holds a cache of quotas that we've updated.  This is used to pull the "really latest" during back to
+	// back quota evaluations that touch the same quota doc.  This only works because we can compare etcd resourceVersions
+	// for the same resource as integers.  Before this change: 22 updates with 12 conflicts.  after this change: 15 updates with 0 conflicts
+	updatedQuotas *lru.Cache
+}
+
+// newQuotaAccessor creates an object that conforms to the QuotaAccessor interface to be used to retrieve quota objects.
+func newQuotaAccessor() (*quotaAccessor, error) {
+	liveLookupCache, err := lru.New(100)
+	if err != nil {
+		return nil, err
+	}
+	updatedCache, err := lru.New(100)
+	if err != nil {
+		return nil, err
+	}
+
+	// client and lister will be set when SetInternalKubeClientSet and SetInternalKubeInformerFactory are invoked
+	return &quotaAccessor{
+		liveLookupCache: liveLookupCache,
+		liveTTL:         time.Duration(30 * time.Second),
+		updatedQuotas:   updatedCache,
+	}, nil
+}
+
+func (e *quotaAccessor) UpdateQuotaStatus(newQuota *corev1.ResourceQuota) error {
+	updatedQuota, err := e.client.CoreV1().ResourceQuotas(newQuota.Namespace).UpdateStatus(context.TODO(),newQuota,metav1.UpdateOptions{})
+	if err != nil {
+		return err
+	}
+
+	key := newQuota.Namespace + "/" + newQuota.Name
+	e.updatedQuotas.Add(key, updatedQuota)
+	return nil
+}
+
+var etcdVersioner = etcd3.APIObjectVersioner{}
+
+// checkCache compares the passed quota against the value in the look-aside cache and returns the newer
+// if the cache is out of date, it deletes the stale entry.  This only works because of etcd resourceVersions
+// being monotonically increasing integers
+func (e *quotaAccessor) checkCache(quota *corev1.ResourceQuota) *corev1.ResourceQuota {
+	key := quota.Namespace + "/" + quota.Name
+	uncastCachedQuota, ok := e.updatedQuotas.Get(key)
+	if !ok {
+		return quota
+	}
+	cachedQuota := uncastCachedQuota.(*corev1.ResourceQuota)
+
+	if etcdVersioner.CompareResourceVersion(quota, cachedQuota) >= 0 {
+		e.updatedQuotas.Remove(key)
+		return quota
+	}
+	return cachedQuota
+}
+
+func (e *quotaAccessor) GetQuotas(namespace string) ([]corev1.ResourceQuota, error) {
+	// determine if there are any quotas in this namespace
+	// if there are no quotas, we don't need to do anything
+	items, err := e.lister.ResourceQuotas(namespace).List(labels.Everything())
+	if err != nil {
+		return nil, fmt.Errorf("error resolving quota: %v", err)
+	}
+
+	// if there are no items held in our indexer, check our live-lookup LRU, if that misses, do the live lookup to prime it.
+	if len(items) == 0 {
+		lruItemObj, ok := e.liveLookupCache.Get(namespace)
+		if !ok || lruItemObj.(liveLookupEntry).expiry.Before(time.Now()) {
+			// TODO: If there are multiple operations at the same time and cache has just expired,
+			// this may cause multiple List operations being issued at the same time.
+			// If there is already in-flight List() for a given namespace, we should wait until
+			// it is finished and cache is updated instead of doing the same, also to avoid
+			// throttling - see #22422 for details.
+			liveList, err := e.client.CoreV1().ResourceQuotas(namespace).List(context.TODO(),metav1.ListOptions{})
+			if err != nil {
+				return nil, err
+			}
+			newEntry := liveLookupEntry{expiry: time.Now().Add(e.liveTTL)}
+			for i := range liveList.Items {
+				newEntry.items = append(newEntry.items, &liveList.Items[i])
+			}
+			e.liveLookupCache.Add(namespace, newEntry)
+			lruItemObj = newEntry
+		}
+		lruEntry := lruItemObj.(liveLookupEntry)
+		for i := range lruEntry.items {
+			items = append(items, lruEntry.items[i])
+		}
+	}
+
+	resourceQuotas := []corev1.ResourceQuota{}
+	for i := range items {
+		quota := items[i]
+		quota = e.checkCache(quota)
+		// always make a copy.  We're going to muck around with this and we should never mutate the originals
+		resourceQuotas = append(resourceQuotas, *quota)
+	}
+
+	return resourceQuotas, nil
+}