Manage sessionSecretsFile

pkg/controller/sessionsecret/session_secret_controller.go

@@ -0,0 +1,227 @@
+package sessionsecret
+
+import (
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/json"
+	"fmt"
+	"time"
+
+	"github.com/golang/glog"
+
+	"k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
+	"k8s.io/apimachinery/pkg/util/wait"
+	informers "k8s.io/client-go/informers/core/v1"
+	kcoreclient "k8s.io/client-go/kubernetes/typed/core/v1"
+	listers "k8s.io/client-go/listers/core/v1"
+	"k8s.io/client-go/tools/cache"
+	"k8s.io/client-go/util/workqueue"
+
+	"github.com/openshift/library-go/pkg/operator/events"
+)
+
+const (
+	sessionSecretNamespace = "openshift-kube-apiserver"
+	sessionSecretName      = "session-secret"
+)
+
+// SessionSecrets struct is copied from github.com/openshift/api/legacyconfig/v1 so we can manually encode and not rely
+// on that package.
+type SessionSecrets struct {
+	metav1.TypeMeta `json:",inline"`
+
+	// Secrets is a list of secrets
+	// New sessions are signed and encrypted using the first secret.
+	// Existing sessions are decrypted/authenticated by each secret until one succeeds. This allows rotating secrets.
+	Secrets []SessionSecret `json:"secrets"`
+}
+
+// SessionSecret is a secret used to authenticate/decrypt cookie-based sessions
+type SessionSecret struct {
+	// Authentication is used to authenticate sessions using HMAC. Recommended to use a secret with 32 or 64 bytes.
+	Authentication string `json:"authentication"`
+	// Encryption is used to encrypt sessions. Must be 16, 24, or 32 characters long, to select AES-128, AES-
+	Encryption string `json:"encryption"`
+}
+
+// Taken from origin but could be moved to library-go
+const (
+	sha256KeyLenBits = sha256.BlockSize * 8 // max key size with HMAC SHA256
+	aes256KeyLenBits = 256                  // max key size with AES (AES-256)
+)
+
+func randomAuthKeyBits() []byte {
+	return randomBits(sha256KeyLenBits)
+}
+
+func randomEncKeyBits() []byte {
+	return randomBits(aes256KeyLenBits)
+}
+
+// randomBits returns a random byte slice with at least the requested bits of entropy.
+// Callers should avoid using a value less than 256 unless they have a very good reason.
+func randomBits(bits int) []byte {
+	size := bits / 8
+	if bits%8 != 0 {
+		size++
+	}
+	b := make([]byte, size)
+	if _, err := rand.Read(b); err != nil {
+		panic(err) // rand should never fail
+	}
+	return b
+}
+
+type SessionSecretController struct {
+	secretLister listers.SecretLister
+	secretClient kcoreclient.SecretsGetter
+
+	secretsHasSynced cache.InformerSynced
+	syncHandler      func(serviceKey string) error
+
+	secretsQueue  workqueue.RateLimitingInterface
+	eventRecorder events.Recorder
+}
+
+func NewSessionSecretController(secrets informers.SecretInformer, secretsClient kcoreclient.SecretsGetter, resyncInterval time.Duration, eventRecorder events.Recorder) *SessionSecretController {
+	sc := &SessionSecretController{
+		secretsQueue: workqueue.NewRateLimitingQueue(workqueue.DefaultControllerRateLimiter()),
+	}
+
+	sc.secretLister = secrets.Lister()
+
+	secrets.Informer().AddEventHandlerWithResyncPeriod(
+		cache.FilteringResourceEventHandler{
+			FilterFunc: isSessionSecret,
+			Handler: cache.ResourceEventHandlerFuncs{
+				AddFunc: sc.enqueueSecret,
+			},
+		},
+		resyncInterval,
+	)
+
+	sc.secretClient = secretsClient
+	sc.secretsHasSynced = secrets.Informer().HasSynced
+
+	sc.syncHandler = sc.syncSecret
+	sc.eventRecorder = eventRecorder
+
+	return sc
+}
+
+// Run begins watching and syncing.
+func (sc *SessionSecretController) Run(workers int, stopCh <-chan struct{}) {
+	defer utilruntime.HandleCrash()
+	defer sc.secretsQueue.ShutDown()
+
+	// Wait for the stores to fill
+	if !cache.WaitForCacheSync(stopCh, sc.secretsHasSynced) {
+		return
+	}
+
+	glog.V(4).Infof("Starting workers for SessionSecretController")
+	for i := 0; i < workers; i++ {
+		go wait.Until(sc.runWorker, time.Second, stopCh)
+	}
+
+	// Add a queue item to trigger initial creation of the secret
+	sc.enqueueSecret(nil)
+
+	<-stopCh
+	glog.V(4).Infof("Shutting down SessionSecretController")
+}
+
+// processNextWorkItem deals with one key off the secretsQueue.  It returns false when it's time to quit.
+func (sc *SessionSecretController) processNextWorkItem() bool {
+	key, quit := sc.secretsQueue.Get()
+	if quit {
+		return false
+	}
+	defer sc.secretsQueue.Done(key)
+
+	err := sc.syncHandler(key.(string))
+	if err != nil {
+		utilruntime.HandleError(fmt.Errorf("%v failed with : %v", key, err))
+		sc.eventRecorder.Warningf("CreateSessionSecretFailure", "%v failed with : %v", key, err)
+		sc.secretsQueue.AddRateLimited(key)
+		return true
+	}
+
+	sc.secretsQueue.Forget(key)
+	return true
+}
+
+func (sc *SessionSecretController) runWorker() {
+	for sc.processNextWorkItem() {
+	}
+}
+
+func newSessionSecretsJSON() ([]byte, error) {
+	secrets := &SessionSecrets{
+		TypeMeta: metav1.TypeMeta{
+			Kind:       "SessionSecrets",
+			APIVersion: "v1",
+		},
+		Secrets: []SessionSecret{
+			{
+				Authentication: string(randomAuthKeyBits()),
+				Encryption:     string(randomEncKeyBits()),
+			},
+		},
+	}
+	return json.Marshal(secrets)
+}
+
+func (sc *SessionSecretController) createSessionSecret() error {
+	secretsBytes, err := newSessionSecretsJSON()
+	if err != nil {
+		return err
+	}
+	secret := &v1.Secret{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      sessionSecretName,
+			Namespace: sessionSecretNamespace,
+		},
+		Data: map[string][]byte{
+			"secrets": secretsBytes,
+		},
+	}
+	_, err = sc.secretClient.Secrets(secret.Namespace).Create(secret)
+	if errors.IsAlreadyExists(err) {
+		return nil
+	}
+	return err
+}
+
+// syncSecret creates the session secret if it doesn't exist.
+func (sc *SessionSecretController) syncSecret(key string) error {
+	namespace, name, err := cache.SplitMetaNamespaceKey(key)
+	if err != nil {
+		return err
+	}
+
+	_, err = sc.secretLister.Secrets(namespace).Get(name)
+	if errors.IsNotFound(err) {
+		glog.V(4).Infof("creating secret %s/%s", namespace, name)
+		return sc.createSessionSecret()
+	}
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (sc *SessionSecretController) enqueueSecret(obj interface{}) {
+	sc.secretsQueue.Add(sessionSecretNamespace + "/" + sessionSecretName)
+}
+
+func isSessionSecret(obj interface{}) bool {
+	secret, ok := obj.(*v1.Secret)
+	if !ok {
+		return false
+	}
+	return secret.Namespace == sessionSecretNamespace && secret.Name == sessionSecretName
+}

pkg/operator/configobservation/authconfig/observe_sessionsecret.go

@@ -0,0 +1,71 @@
+package authconfig
+
+import (
+	"github.com/golang/glog"
+
+	"k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+
+	"github.com/openshift/cluster-kube-apiserver-operator/pkg/operator/configobservation"
+	"github.com/openshift/library-go/pkg/operator/configobserver"
+	"github.com/openshift/library-go/pkg/operator/events"
+)
+
+const (
+	sessionSecretNamespace = "openshift-kube-apiserver"
+	sessionSecretName      = "session-secret"
+	sessionSecretPath      = "/etc/kubernetes/static-pod-resources/secrets/session-secret/secret"
+)
+
+// ObserveSessionSecret sets/unsets the oauthConfig sessionSecretsFile depending on if session-secret exists.
+func ObserveSessionSecret(genericListers configobserver.Listers, recorder events.Recorder, existingConfig map[string]interface{}) (map[string]interface{}, []error) {
+	listers := genericListers.(configobservation.Listers)
+	errs := []error{}
+	prevObservedConfig := map[string]interface{}{}
+
+	oauthConfigSessionSecretsFilePath := []string{"oauthConfig", "sessionConfig", "sessionSecretsFile"}
+	currentSessionSecretsFilePath, _, err := unstructured.NestedString(existingConfig, oauthConfigSessionSecretsFilePath...)
+	if err != nil {
+		errs = append(errs, err)
+	}
+	if len(currentSessionSecretsFilePath) > 0 {
+		if err := unstructured.SetNestedField(prevObservedConfig, currentSessionSecretsFilePath, oauthConfigSessionSecretsFilePath...); err != nil {
+			errs = append(errs, err)
+		}
+	}
+
+	if !listers.SecretHasSynced() {
+		glog.Warningf("secrets not synced")
+		return prevObservedConfig, errs
+	}
+
+	observedConfig := map[string]interface{}{}
+	_, err = listers.SecretLister.Secrets(sessionSecretNamespace).Get(sessionSecretName)
+	if errors.IsNotFound(err) {
+		glog.Warningf("session secret %s/%s not found", sessionSecretNamespace, sessionSecretName)
+		// Unset the value if we need to.
+		if len(currentSessionSecretsFilePath) > 0 {
+			err := unstructured.SetNestedField(observedConfig, "", oauthConfigSessionSecretsFilePath...)
+			if err != nil {
+				errs = append(errs, err)
+			}
+		}
+		return observedConfig, errs
+	}
+	if err != nil {
+		return prevObservedConfig, errs
+	}
+
+	// Secret is found and sessionSecretPath is already set.
+	if len(currentSessionSecretsFilePath) > 0 {
+		return prevObservedConfig, errs
+	}
+
+	// Set sessionSecretPath
+	err = unstructured.SetNestedField(observedConfig, sessionSecretPath, oauthConfigSessionSecretsFilePath...)
+	if err != nil {
+		errs = append(errs, err)
+	}
+
+	return observedConfig, errs
+}

pkg/operator/configobservation/authconfig/observe_sessionsecret_test.go

@@ -0,0 +1,65 @@
+package authconfig
+
+import (
+	"testing"
+
+	"github.com/openshift/cluster-kube-apiserver-operator/pkg/operator/configobservation"
+
+	"k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	v12 "k8s.io/client-go/listers/core/v1"
+	"k8s.io/client-go/tools/cache"
+)
+
+func TestObserveSessionSecret(t *testing.T) {
+	indexer := cache.NewIndexer(cache.MetaNamespaceKeyFunc, cache.Indexers{})
+	secret := &v1.Secret{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      sessionSecretName,
+			Namespace: sessionSecretNamespace,
+		},
+	}
+	indexer.Add(secret)
+
+	listers := configobservation.Listers{
+		SecretLister: v12.NewSecretLister(indexer),
+	}
+	result, errs := ObserveSessionSecret(listers, nil, map[string]interface{}{})
+	if len(errs) > 0 {
+		t.Error("expected len(errs) == 0")
+	}
+	secretPath, _, err := unstructured.NestedString(result, "oauthConfig", "sessionConfig", "sessionSecretsFile")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if secretPath != sessionSecretPath {
+		t.Errorf("expected oauthConfig.sessionConfig.sessionSecretsFile: %s, got %s", sessionSecretPath, secretPath)
+	}
+}
+
+func TestDeleteSessionSecret(t *testing.T) {
+	indexer := cache.NewIndexer(cache.MetaNamespaceKeyFunc, cache.Indexers{})
+
+	listers := configobservation.Listers{
+		SecretLister: v12.NewSecretLister(indexer),
+	}
+	existingConfig := map[string]interface{}{}
+	oauthConfigSessionSecretsFilePath := []string{"oauthConfig", "sessionConfig", "sessionSecretsFile"}
+
+	err := unstructured.SetNestedField(existingConfig, "foobar", oauthConfigSessionSecretsFilePath...)
+	if err != nil {
+		t.Fatal(err)
+	}
+	result, errs := ObserveSessionSecret(listers, nil, existingConfig)
+	if len(errs) > 0 {
+		t.Error("expected len(errs) == 0")
+	}
+	secretPath, _, err := unstructured.NestedString(result, "oauthConfig", "sessionConfig", "sessionSecretsFile")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(secretPath) > 0 {
+		t.Errorf("expected oauthConfig.sessionConfig.sessionSecretsFile: \"\", got %s", secretPath)
+	}
+}