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Commit 8e552205 authored by wojtekt's avatar wojtekt
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Refactor cachingSecretManager

parent 8eb7eeef
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Showing with 244 additions and 201 deletions
pkg/kubelet/secret/BUILD
View file @ 8e552205
......@@ -8,7 +8,7 @@ load(
go_test(
name = "go_default_test",
srcs = ["secret_manager_test.go"],
srcs = ["caching_secret_manager_test.go"],
embed = [":go_default_library"],
deps = [
"//vendor/github.com/stretchr/testify/assert:go_default_library",
......@@ -25,6 +25,7 @@ go_test(
go_library(
name = "go_default_library",
srcs = [
"caching_secret_manager.go",
"fake_manager.go",
"secret_manager.go",
],
......
pkg/kubelet/secret/caching_secret_manager.go 0 → 100644
View file @ 8e552205
/*
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 secret
import (
"fmt"
"strconv"
"sync"
"time"
"k8s.io/api/core/v1"
storageetcd "k8s.io/apiserver/pkg/storage/etcd"
clientset "k8s.io/client-go/kubernetes"
"k8s.io/kubernetes/pkg/kubelet/util"
apierrors "k8s.io/apimachinery/pkg/api/errors"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/util/clock"
)
const (
defaultTTL = time.Minute
)
type GetObjectTTLFunc func() (time.Duration, bool)
// secretStoreItems is a single item stored in secretStore.
type secretStoreItem struct {
refCount int
secret *secretData
}
type secretData struct {
sync.Mutex
secret *v1.Secret
err error
lastUpdateTime time.Time
}
// secretStore is a local cache of secrets.
type secretStore struct {
kubeClient clientset.Interface
clock clock.Clock
lock sync.Mutex
items map[objectKey]*secretStoreItem
defaultTTL time.Duration
getTTL GetObjectTTLFunc
}
func newSecretStore(kubeClient clientset.Interface, clock clock.Clock, getTTL GetObjectTTLFunc, ttl time.Duration) *secretStore {
return &secretStore{
kubeClient: kubeClient,
clock: clock,
items: make(map[objectKey]*secretStoreItem),
defaultTTL: ttl,
getTTL: getTTL,
}
}
func isSecretOlder(newSecret, oldSecret *v1.Secret) bool {
if newSecret == nil || oldSecret == nil {
return false
}
newVersion, _ := storageetcd.Versioner.ObjectResourceVersion(newSecret)
oldVersion, _ := storageetcd.Versioner.ObjectResourceVersion(oldSecret)
return newVersion < oldVersion
}
func (s *secretStore) Add(namespace, name string) {
key := objectKey{namespace: namespace, name: name}
// Add is called from RegisterPod, thus it needs to be efficient.
// Thus Add() is only increasing refCount and generation of a given secret.
// Then Get() is responsible for fetching if needed.
s.lock.Lock()
defer s.lock.Unlock()
item, exists := s.items[key]
if !exists {
item = &secretStoreItem{
refCount: 0,
secret: &secretData{},
}
s.items[key] = item
}
item.refCount++
// This will trigger fetch on the next Get() operation.
item.secret = nil
}
func (s *secretStore) Delete(namespace, name string) {
key := objectKey{namespace: namespace, name: name}
s.lock.Lock()
defer s.lock.Unlock()
if item, ok := s.items[key]; ok {
item.refCount--
if item.refCount == 0 {
delete(s.items, key)
}
}
}
func GetObjectTTLFromNodeFunc(getNode func() (*v1.Node, error)) GetObjectTTLFunc {
return func() (time.Duration, bool) {
node, err := getNode()
if err != nil {
return time.Duration(0), false
}
if node != nil && node.Annotations != nil {
if value, ok := node.Annotations[v1.ObjectTTLAnnotationKey]; ok {
if intValue, err := strconv.Atoi(value); err == nil {
return time.Duration(intValue) * time.Second, true
}
}
}
return time.Duration(0), false
}
}
func (s *secretStore) isSecretFresh(data *secretData) bool {
secretTTL := s.defaultTTL
if ttl, ok := s.getTTL(); ok {
secretTTL = ttl
}
return s.clock.Now().Before(data.lastUpdateTime.Add(secretTTL))
}
func (s *secretStore) Get(namespace, name string) (*v1.Secret, error) {
key := objectKey{namespace: namespace, name: name}
data := func() *secretData {
s.lock.Lock()
defer s.lock.Unlock()
item, exists := s.items[key]
if !exists {
return nil
}
if item.secret == nil {
item.secret = &secretData{}
}
return item.secret
}()
if data == nil {
return nil, fmt.Errorf("secret %q/%q not registered", namespace, name)
}
// After updating data in secretStore, lock the data, fetch secret if
// needed and return data.
data.Lock()
defer data.Unlock()
if data.err != nil || !s.isSecretFresh(data) {
opts := metav1.GetOptions{}
if data.secret != nil && data.err == nil {
// This is just a periodic refresh of a secret we successfully fetched previously.
// In this case, server data from apiserver cache to reduce the load on both
// etcd and apiserver (the cache is eventually consistent).
util.FromApiserverCache(&opts)
}
secret, err := s.kubeClient.CoreV1().Secrets(namespace).Get(name, opts)
if err != nil && !apierrors.IsNotFound(err) && data.secret == nil && data.err == nil {
// Couldn't fetch the latest secret, but there is no cached data to return.
// Return the fetch result instead.
return secret, err
}
if (err == nil && !isSecretOlder(secret, data.secret)) || apierrors.IsNotFound(err) {
// If the fetch succeeded with a newer version of the secret, or if the
// secret could not be found in the apiserver, update the cached data to
// reflect the current status.
data.secret = secret
data.err = err
data.lastUpdateTime = s.clock.Now()
}
}
return data.secret, data.err
}
// NewCachingSecretManager creates a manager that keeps a cache of all secrets
// necessary for registered pods.
// It implements the following logic:
// - whenever a pod is created or updated, the cached versions of all its secrets
// are invalidated
// - every GetSecret() call tries to fetch the value from local cache; if it is
// not there, invalidated or too old, we fetch it from apiserver and refresh the
// value in cache; otherwise it is just fetched from cache
func NewCachingSecretManager(kubeClient clientset.Interface, getTTL GetObjectTTLFunc) Manager {
secretStore := newSecretStore(kubeClient, clock.RealClock{}, getTTL, defaultTTL)
return newCacheBasedSecretManager(secretStore)
}
pkg/kubelet/secret/secret_manager_test.go → pkg/kubelet/secret/caching_secret_manager_test.go
View file @ 8e552205
......@@ -345,10 +345,7 @@ func TestCacheInvalidation(t *testing.T) {
fakeClient := &fake.Clientset{}
fakeClock := clock.NewFakeClock(time.Now())
store := newSecretStore(fakeClient, fakeClock, noObjectTTL, time.Minute)
manager := &cachingSecretManager{
secretStore: store,
registeredPods: make(map[objectKey]*v1.Pod),
}
manager := newCacheBasedSecretManager(store)
// Create a pod with some secrets.
s1 := secretsToAttach{
......@@ -403,10 +400,7 @@ func TestCacheRefcounts(t *testing.T) {
fakeClient := &fake.Clientset{}
fakeClock := clock.NewFakeClock(time.Now())
store := newSecretStore(fakeClient, fakeClock, noObjectTTL, time.Minute)
manager := &cachingSecretManager{
secretStore: store,
registeredPods: make(map[objectKey]*v1.Pod),
}
manager := newCacheBasedSecretManager(store)
s1 := secretsToAttach{
imagePullSecretNames: []string{"s1"},
......@@ -490,10 +484,7 @@ func TestCacheRefcounts(t *testing.T) {
func TestCachingSecretManager(t *testing.T) {
fakeClient := &fake.Clientset{}
secretStore := newSecretStore(fakeClient, clock.RealClock{}, noObjectTTL, 0)
manager := &cachingSecretManager{
secretStore: secretStore,
registeredPods: make(map[objectKey]*v1.Pod),
}
manager := newCacheBasedSecretManager(secretStore)
// Create a pod with some secrets.
s1 := secretsToAttach{
......
pkg/kubelet/secret/secret_manager.go
View file @ 8e552205
......@@ -17,27 +17,16 @@ limitations under the License.
package secret
import (
"fmt"
"strconv"
"sync"
"time"
"k8s.io/api/core/v1"
storageetcd "k8s.io/apiserver/pkg/storage/etcd"
clientset "k8s.io/client-go/kubernetes"
podutil "k8s.io/kubernetes/pkg/api/v1/pod"
"k8s.io/kubernetes/pkg/kubelet/util"
apierrors "k8s.io/apimachinery/pkg/api/errors"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/util/clock"
"k8s.io/apimachinery/pkg/util/sets"
)
const (
defaultTTL = time.Minute
)
type Manager interface {
// Get secret by secret namespace and name.
GetSecret(namespace, name string) (*v1.Secret, error)
......@@ -53,6 +42,11 @@ type Manager interface {
UnregisterPod(pod *v1.Pod)
}
type objectKey struct {
namespace string
name string
}
// simpleSecretManager implements SecretManager interfaces with
// simple operations to apiserver.
type simpleSecretManager struct {
......@@ -73,190 +67,41 @@ func (s *simpleSecretManager) RegisterPod(pod *v1.Pod) {
func (s *simpleSecretManager) UnregisterPod(pod *v1.Pod) {
}
type GetObjectTTLFunc func() (time.Duration, bool)
type objectKey struct {
namespace string
name string
}
// secretStoreItems is a single item stored in secretStore.
type secretStoreItem struct {
refCount int
secret *secretData
}
type secretData struct {
sync.Mutex
secret *v1.Secret
err error
lastUpdateTime time.Time
}
// secretStore is a local cache of secrets.
type secretStore struct {
kubeClient clientset.Interface
clock clock.Clock
lock sync.Mutex
items map[objectKey]*secretStoreItem
defaultTTL time.Duration
getTTL GetObjectTTLFunc
}
func newSecretStore(kubeClient clientset.Interface, clock clock.Clock, getTTL GetObjectTTLFunc, ttl time.Duration) *secretStore {
return &secretStore{
kubeClient: kubeClient,
clock: clock,
items: make(map[objectKey]*secretStoreItem),
defaultTTL: ttl,
getTTL: getTTL,
}
}
func isSecretOlder(newSecret, oldSecret *v1.Secret) bool {
if newSecret == nil || oldSecret == nil {
return false
}
newVersion, _ := storageetcd.Versioner.ObjectResourceVersion(newSecret)
oldVersion, _ := storageetcd.Versioner.ObjectResourceVersion(oldSecret)
return newVersion < oldVersion
}
func (s *secretStore) Add(namespace, name string) {
key := objectKey{namespace: namespace, name: name}
// Add is called from RegisterPod, thus it needs to be efficient.
// Thus Add() is only increasing refCount and generation of a given secret.
// Then Get() is responsible for fetching if needed.
s.lock.Lock()
defer s.lock.Unlock()
item, exists := s.items[key]
if !exists {
item = &secretStoreItem{
refCount: 0,
secret: &secretData{},
}
s.items[key] = item
}
item.refCount++
// This will trigger fetch on the next Get() operation.
item.secret = nil
}
func (s *secretStore) Delete(namespace, name string) {
key := objectKey{namespace: namespace, name: name}
s.lock.Lock()
defer s.lock.Unlock()
if item, ok := s.items[key]; ok {
item.refCount--
if item.refCount == 0 {
delete(s.items, key)
}
}
}
func GetObjectTTLFromNodeFunc(getNode func() (*v1.Node, error)) GetObjectTTLFunc {
return func() (time.Duration, bool) {
node, err := getNode()
if err != nil {
return time.Duration(0), false
}
if node != nil && node.Annotations != nil {
if value, ok := node.Annotations[v1.ObjectTTLAnnotationKey]; ok {
if intValue, err := strconv.Atoi(value); err == nil {
return time.Duration(intValue) * time.Second, true
}
}
}
return time.Duration(0), false
}
}
func (s *secretStore) isSecretFresh(data *secretData) bool {
secretTTL := s.defaultTTL
if ttl, ok := s.getTTL(); ok {
secretTTL = ttl
}
return s.clock.Now().Before(data.lastUpdateTime.Add(secretTTL))
}
func (s *secretStore) Get(namespace, name string) (*v1.Secret, error) {
key := objectKey{namespace: namespace, name: name}
data := func() *secretData {
s.lock.Lock()
defer s.lock.Unlock()
item, exists := s.items[key]
if !exists {
return nil
}
if item.secret == nil {
item.secret = &secretData{}
}
return item.secret
}()
if data == nil {
return nil, fmt.Errorf("secret %q/%q not registered", namespace, name)
}
// After updating data in secretStore, lock the data, fetch secret if
// needed and return data.
data.Lock()
defer data.Unlock()
if data.err != nil || !s.isSecretFresh(data) {
opts := metav1.GetOptions{}
if data.secret != nil && data.err == nil {
// This is just a periodic refresh of a secret we successfully fetched previously.
// In this case, server data from apiserver cache to reduce the load on both
// etcd and apiserver (the cache is eventually consistent).
util.FromApiserverCache(&opts)
}
secret, err := s.kubeClient.CoreV1().Secrets(namespace).Get(name, opts)
if err != nil && !apierrors.IsNotFound(err) && data.secret == nil && data.err == nil {
// Couldn't fetch the latest secret, but there is no cached data to return.
// Return the fetch result instead.
return secret, err
}
if (err == nil && !isSecretOlder(secret, data.secret)) || apierrors.IsNotFound(err) {
// If the fetch succeeded with a newer version of the secret, or if the
// secret could not be found in the apiserver, update the cached data to
// reflect the current status.
data.secret = secret
data.err = err
data.lastUpdateTime = s.clock.Now()
}
}
return data.secret, data.err
}
// cachingSecretManager keeps a cache of all secrets necessary for registered pods.
// It implements the following logic:
// - whenever a pod is created or updated, the cached versions of all its secrets
// are invalidated
// - every GetSecret() call tries to fetch the value from local cache; if it is
// not there, invalidated or too old, we fetch it from apiserver and refresh the
// value in cache; otherwise it is just fetched from cache
type cachingSecretManager struct {
secretStore *secretStore
// store is the interface for a secrets cache that
// can be used by cacheBasedSecretManager.
type store interface {
// Add a secret to the store.
// Note that multiple additions to the store has to be allowed
// in the implementations and effectively treated as refcounted.
Add(namespace, name string)
// Delete a secret from the store.
// Note that secret should be deleted only when there was a
// corresponding Delete call for each of Add calls (effectively
// when refcount was reduced to zero).
Delete(namespace, name string)
// Get a secret from a store.
Get(namespace, name string) (*v1.Secret, error)
}
// cachingBasedSecretManager keeps a store with secrets necessary
// for registered pods. Different implementations of the store
// may result in different semantics for freshness of secrets
// (e.g. ttl-based implementation vs watch-based implementation).
type cacheBasedSecretManager struct {
secretStore store
lock sync.Mutex
registeredPods map[objectKey]*v1.Pod
}
func NewCachingSecretManager(kubeClient clientset.Interface, getTTL GetObjectTTLFunc) Manager {
csm := &cachingSecretManager{
secretStore: newSecretStore(kubeClient, clock.RealClock{}, getTTL, defaultTTL),
func newCacheBasedSecretManager(secretStore store) Manager {
return &cacheBasedSecretManager{
secretStore: secretStore,
registeredPods: make(map[objectKey]*v1.Pod),
}
return csm
}
func (c *cachingSecretManager) GetSecret(namespace, name string) (*v1.Secret, error) {
func (c *cacheBasedSecretManager) GetSecret(namespace, name string) (*v1.Secret, error) {
return c.secretStore.Get(namespace, name)
}
......@@ -269,7 +114,7 @@ func getSecretNames(pod *v1.Pod) sets.String {
return result
}
func (c *cachingSecretManager) RegisterPod(pod *v1.Pod) {
func (c *cacheBasedSecretManager) RegisterPod(pod *v1.Pod) {
names := getSecretNames(pod)
c.lock.Lock()
defer c.lock.Unlock()
......@@ -292,7 +137,7 @@ func (c *cachingSecretManager) RegisterPod(pod *v1.Pod) {
}
}
func (c *cachingSecretManager) UnregisterPod(pod *v1.Pod) {
func (c *cacheBasedSecretManager) UnregisterPod(pod *v1.Pod) {
var prev *v1.Pod
key := objectKey{namespace: pod.Namespace, name: pod.Name}
c.lock.Lock()
......
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