New etcd client modifications part 1 (context support)

This commit plumbs contexts which are needed for the new client.

pkg/api/context.go

@@ -18,14 +18,32 @@ package api
 
 import (
 	stderrs "errors"
+	"time"
 
 	"golang.org/x/net/context"
 	"k8s.io/kubernetes/pkg/auth/user"
 )
 
 // Context carries values across API boundaries.
+// This context matches the context.Context interface
+// (https://blog.golang.org/context), for the purposes
+// of passing the api.Context through to the storage tier.
+// TODO: Determine the extent that this abstraction+interface
+// is used by the api, and whether we can remove.
 type Context interface {
+	// Value returns the value associated with key or nil if none.
 	Value(key interface{}) interface{}
+
+	// Deadline returns the time when this Context will be canceled, if any.
+	Deadline() (deadline time.Time, ok bool)
+
+	// Done returns a channel that is closed when this Context is canceled
+	// or times out.
+	Done() <-chan struct{}
+
+	// Err indicates why this context was canceled, after the Done channel
+	// is closed.
+	Err() error
 }
 
 // The key type is unexported to prevent collisions

pkg/master/master.go

@@ -90,6 +90,7 @@ import (
 	"github.com/emicklei/go-restful/swagger"
 	"github.com/golang/glog"
 	"github.com/prometheus/client_golang/prometheus"
+	"golang.org/x/net/context"
 	"k8s.io/kubernetes/pkg/registry/service/allocator"
 	"k8s.io/kubernetes/pkg/registry/service/portallocator"
 )
@@ -152,13 +153,13 @@ func (s *StorageDestinations) backends() []string {
 	backends := sets.String{}
 	for _, group := range s.APIGroups {
 		if group.Default != nil {
-			for _, backend := range group.Default.Backends() {
+			for _, backend := range group.Default.Backends(context.TODO()) {
 				backends.Insert(backend)
 			}
 		}
 		if group.Overrides != nil {
 			for _, storage := range group.Overrides {
-				for _, backend := range storage.Backends() {
+				for _, backend := range storage.Backends(context.TODO()) {
 					backends.Insert(backend)
 				}
 			}

pkg/registry/generic/etcd/etcd.go

@@ -156,7 +156,7 @@ func (e *Etcd) ListPredicate(ctx api.Context, m generic.Matcher) (runtime.Object
 	if name, ok := m.MatchesSingle(); ok {
 		if key, err := e.KeyFunc(ctx, name); err == nil {
 			trace.Step("About to read single object")
-			err := e.Storage.GetToList(key, filterFunc, list)
+			err := e.Storage.GetToList(ctx, key, filterFunc, list)
 			trace.Step("Object extracted")
 			if err != nil {
 				return nil, err
@@ -167,7 +167,7 @@ func (e *Etcd) ListPredicate(ctx api.Context, m generic.Matcher) (runtime.Object
 	}
 
 	trace.Step("About to list directory")
-	err := e.Storage.List(e.KeyRootFunc(ctx), filterFunc, list)
+	err := e.Storage.List(ctx, e.KeyRootFunc(ctx), filterFunc, list)
 	trace.Step("List extracted")
 	if err != nil {
 		return nil, err
@@ -196,7 +196,7 @@ func (e *Etcd) Create(ctx api.Context, obj runtime.Object) (runtime.Object, erro
 	}
 	trace.Step("About to create object")
 	out := e.NewFunc()
-	if err := e.Storage.Create(key, obj, out, ttl); err != nil {
+	if err := e.Storage.Create(ctx, key, obj, out, ttl); err != nil {
 		err = etcderr.InterpretCreateError(err, e.EndpointName, name)
 		err = rest.CheckGeneratedNameError(e.CreateStrategy, err, obj)
 		return nil, err
@@ -240,7 +240,7 @@ func (e *Etcd) Update(ctx api.Context, obj runtime.Object) (runtime.Object, bool
 	// TODO: expose TTL
 	creating := false
 	out := e.NewFunc()
-	err = e.Storage.GuaranteedUpdate(key, out, true, func(existing runtime.Object, res storage.ResponseMeta) (runtime.Object, *uint64, error) {
+	err = e.Storage.GuaranteedUpdate(ctx, key, out, true, func(existing runtime.Object, res storage.ResponseMeta) (runtime.Object, *uint64, error) {
 		version, err := e.Storage.Versioner().ObjectResourceVersion(existing)
 		if err != nil {
 			return nil, nil, err
@@ -330,7 +330,7 @@ func (e *Etcd) Get(ctx api.Context, name string) (runtime.Object, error) {
 		return nil, err
 	}
 	trace.Step("About to read object")
-	if err := e.Storage.Get(key, obj, false); err != nil {
+	if err := e.Storage.Get(ctx, key, obj, false); err != nil {
 		return nil, etcderr.InterpretGetError(err, e.EndpointName, name)
 	}
 	trace.Step("Object read")
@@ -358,7 +358,7 @@ func (e *Etcd) Delete(ctx api.Context, name string, options *api.DeleteOptions)
 	trace := util.NewTrace("Delete " + reflect.TypeOf(obj).String())
 	defer trace.LogIfLong(time.Second)
 	trace.Step("About to read object")
-	if err := e.Storage.Get(key, obj, false); err != nil {
+	if err := e.Storage.Get(ctx, key, obj, false); err != nil {
 		return nil, etcderr.InterpretDeleteError(err, e.EndpointName, name)
 	}
 
@@ -378,7 +378,7 @@ func (e *Etcd) Delete(ctx api.Context, name string, options *api.DeleteOptions)
 		out := e.NewFunc()
 		lastGraceful := int64(0)
 		err := e.Storage.GuaranteedUpdate(
-			key, out, false,
+			ctx, key, out, false,
 			storage.SimpleUpdate(func(existing runtime.Object) (runtime.Object, error) {
 				graceful, pendingGraceful, err := rest.BeforeDelete(e.DeleteStrategy, ctx, existing, options)
 				if err != nil {
@@ -413,7 +413,7 @@ func (e *Etcd) Delete(ctx api.Context, name string, options *api.DeleteOptions)
 	// delete immediately, or no graceful deletion supported
 	out := e.NewFunc()
 	trace.Step("About to delete object")
-	if err := e.Storage.Delete(key, out); err != nil {
+	if err := e.Storage.Delete(ctx, key, out); err != nil {
 		return nil, etcderr.InterpretDeleteError(err, e.EndpointName, name)
 	}
 	return e.finalizeDelete(out, true)
@@ -457,12 +457,12 @@ func (e *Etcd) WatchPredicate(ctx api.Context, m generic.Matcher, resourceVersio
 			if err != nil {
 				return nil, err
 			}
-			return e.Storage.Watch(key, version, filterFunc)
+			return e.Storage.Watch(ctx, key, version, filterFunc)
 		}
 		// if we cannot extract a key based on the current context, the optimization is skipped
 	}
 
-	return e.Storage.WatchList(e.KeyRootFunc(ctx), version, filterFunc)
+	return e.Storage.WatchList(ctx, e.KeyRootFunc(ctx), version, filterFunc)
 }
 
 func (e *Etcd) filterAndDecorateFunction(m generic.Matcher) func(runtime.Object) bool {

pkg/registry/pod/etcd/etcd.go

@@ -160,7 +160,7 @@ func (r *BindingREST) setPodHostAndAnnotations(ctx api.Context, podID, oldMachin
 	if err != nil {
 		return nil, err
 	}
-	err = r.store.Storage.GuaranteedUpdate(podKey, &api.Pod{}, false, storage.SimpleUpdate(func(obj runtime.Object) (runtime.Object, error) {
+	err = r.store.Storage.GuaranteedUpdate(ctx, podKey, &api.Pod{}, false, storage.SimpleUpdate(func(obj runtime.Object) (runtime.Object, error) {
 		pod, ok := obj.(*api.Pod)
 		if !ok {
 			return nil, fmt.Errorf("unexpected object: %#v", obj)

pkg/registry/service/allocator/etcd/etcd.go

@@ -29,6 +29,8 @@ import (
 	"k8s.io/kubernetes/pkg/runtime"
 	"k8s.io/kubernetes/pkg/storage"
 	etcdstorage "k8s.io/kubernetes/pkg/storage/etcd"
+
+	"golang.org/x/net/context"
 )
 
 var (
@@ -141,7 +143,7 @@ func (e *Etcd) Release(item int) error {
 
 // tryUpdate performs a read-update to persist the latest snapshot state of allocation.
 func (e *Etcd) tryUpdate(fn func() error) error {
-	err := e.storage.GuaranteedUpdate(e.baseKey, &api.RangeAllocation{}, true,
+	err := e.storage.GuaranteedUpdate(context.TODO(), e.baseKey, &api.RangeAllocation{}, true,
 		storage.SimpleUpdate(func(input runtime.Object) (output runtime.Object, err error) {
 			existing := input.(*api.RangeAllocation)
 			if len(existing.ResourceVersion) == 0 {
@@ -171,7 +173,7 @@ func (e *Etcd) Refresh() (*api.RangeAllocation, error) {
 	defer e.lock.Unlock()
 
 	existing := &api.RangeAllocation{}
-	if err := e.storage.Get(e.baseKey, existing, false); err != nil {
+	if err := e.storage.Get(context.TODO(), e.baseKey, existing, false); err != nil {
 		if etcdstorage.IsEtcdNotFound(err) {
 			return nil, nil
 		}
@@ -185,7 +187,7 @@ func (e *Etcd) Refresh() (*api.RangeAllocation, error) {
 // etcd. If the key does not exist, the object will have an empty ResourceVersion.
 func (e *Etcd) Get() (*api.RangeAllocation, error) {
 	existing := &api.RangeAllocation{}
-	if err := e.storage.Get(e.baseKey, existing, true); err != nil {
+	if err := e.storage.Get(context.TODO(), e.baseKey, existing, true); err != nil {
 		return nil, etcderr.InterpretGetError(err, e.kind, "")
 	}
 	return existing, nil
@@ -198,7 +200,7 @@ func (e *Etcd) CreateOrUpdate(snapshot *api.RangeAllocation) error {
 	defer e.lock.Unlock()
 
 	last := ""
-	err := e.storage.GuaranteedUpdate(e.baseKey, &api.RangeAllocation{}, true,
+	err := e.storage.GuaranteedUpdate(context.TODO(), e.baseKey, &api.RangeAllocation{}, true,
 		storage.SimpleUpdate(func(input runtime.Object) (output runtime.Object, err error) {
 			existing := input.(*api.RangeAllocation)
 			switch {

pkg/registry/service/allocator/etcd/etcd_test.go

@@ -27,6 +27,8 @@ import (
 	"k8s.io/kubernetes/pkg/runtime"
 	"k8s.io/kubernetes/pkg/tools"
 	"k8s.io/kubernetes/pkg/tools/etcdtest"
+
+	"golang.org/x/net/context"
 )
 
 func newStorage(t *testing.T) (*Etcd, *tools.FakeEtcdClient, allocator.Interface) {
@@ -84,7 +86,7 @@ func TestStore(t *testing.T) {
 	other := allocator.NewAllocationMap(100, "rangeSpecValue")
 
 	allocation := &api.RangeAllocation{}
-	if err := storage.storage.Get(key(), allocation, false); err != nil {
+	if err := storage.storage.Get(context.TODO(), key(), allocation, false); err != nil {
 		t.Fatal(err)
 	}
 	if allocation.ResourceVersion != "2" {

pkg/storage/cacher.go

@@ -31,6 +31,7 @@ import (
 	"k8s.io/kubernetes/pkg/watch"
 
 	"github.com/golang/glog"
+	"golang.org/x/net/context"
 )
 
 // CacherConfig contains the configuration for a given Cache.
@@ -152,8 +153,8 @@ func (c *Cacher) startCaching(stopChannel <-chan struct{}) {
 }
 
 // Implements storage.Interface.
-func (c *Cacher) Backends() []string {
+func (c *Cacher) Backends(ctx context.Context) []string {
-	return c.storage.Backends()
+	return c.storage.Backends(ctx)
 }
 
 // Implements storage.Interface.
@@ -162,22 +163,22 @@ func (c *Cacher) Versioner() Versioner {
 }
 
 // Implements storage.Interface.
-func (c *Cacher) Create(key string, obj, out runtime.Object, ttl uint64) error {
+func (c *Cacher) Create(ctx context.Context, key string, obj, out runtime.Object, ttl uint64) error {
-	return c.storage.Create(key, obj, out, ttl)
+	return c.storage.Create(ctx, key, obj, out, ttl)
 }
 
 // Implements storage.Interface.
-func (c *Cacher) Set(key string, obj, out runtime.Object, ttl uint64) error {
+func (c *Cacher) Set(ctx context.Context, key string, obj, out runtime.Object, ttl uint64) error {
-	return c.storage.Set(key, obj, out, ttl)
+	return c.storage.Set(ctx, key, obj, out, ttl)
 }
 
 // Implements storage.Interface.
-func (c *Cacher) Delete(key string, out runtime.Object) error {
+func (c *Cacher) Delete(ctx context.Context, key string, out runtime.Object) error {
-	return c.storage.Delete(key, out)
+	return c.storage.Delete(ctx, key, out)
 }
 
 // Implements storage.Interface.
-func (c *Cacher) Watch(key string, resourceVersion uint64, filter FilterFunc) (watch.Interface, error) {
+func (c *Cacher) Watch(ctx context.Context, key string, resourceVersion uint64, filter FilterFunc) (watch.Interface, error) {
 	// Do NOT allow Watch to start when the underlying structures are not propagated.
 	c.usable.RLock()
 	defer c.usable.RUnlock()
@@ -203,23 +204,23 @@ func (c *Cacher) Watch(key string, resourceVersion uint64, filter FilterFunc) (w
 }
 
 // Implements storage.Interface.
-func (c *Cacher) WatchList(key string, resourceVersion uint64, filter FilterFunc) (watch.Interface, error) {
+func (c *Cacher) WatchList(ctx context.Context, key string, resourceVersion uint64, filter FilterFunc) (watch.Interface, error) {
-	return c.Watch(key, resourceVersion, filter)
+	return c.Watch(ctx, key, resourceVersion, filter)
 }
 
 // Implements storage.Interface.
-func (c *Cacher) Get(key string, objPtr runtime.Object, ignoreNotFound bool) error {
+func (c *Cacher) Get(ctx context.Context, key string, objPtr runtime.Object, ignoreNotFound bool) error {
-	return c.storage.Get(key, objPtr, ignoreNotFound)
+	return c.storage.Get(ctx, key, objPtr, ignoreNotFound)
 }
 
 // Implements storage.Interface.
-func (c *Cacher) GetToList(key string, filter FilterFunc, listObj runtime.Object) error {
+func (c *Cacher) GetToList(ctx context.Context, key string, filter FilterFunc, listObj runtime.Object) error {
-	return c.storage.GetToList(key, filter, listObj)
+	return c.storage.GetToList(ctx, key, filter, listObj)
 }
 
 // Implements storage.Interface.
-func (c *Cacher) List(key string, filter FilterFunc, listObj runtime.Object) error {
+func (c *Cacher) List(ctx context.Context, key string, filter FilterFunc, listObj runtime.Object) error {
-	return c.storage.List(key, filter, listObj)
+	return c.storage.List(ctx, key, filter, listObj)
 }
 
 // ListFromMemory implements list operation (the same signature as List method)
@@ -263,8 +264,8 @@ func (c *Cacher) ListFromMemory(key string, listObj runtime.Object) error {
 }
 
 // Implements storage.Interface.
-func (c *Cacher) GuaranteedUpdate(key string, ptrToType runtime.Object, ignoreNotFound bool, tryUpdate UpdateFunc) error {
+func (c *Cacher) GuaranteedUpdate(ctx context.Context, key string, ptrToType runtime.Object, ignoreNotFound bool, tryUpdate UpdateFunc) error {
-	return c.storage.GuaranteedUpdate(key, ptrToType, ignoreNotFound, tryUpdate)
+	return c.storage.GuaranteedUpdate(ctx, key, ptrToType, ignoreNotFound, tryUpdate)
 }
 
 // Implements storage.Interface.
@@ -343,7 +344,7 @@ func newCacherListerWatcher(storage Interface, resourcePrefix string, newListFun
 // Implements cache.ListerWatcher interface.
 func (lw *cacherListerWatcher) List() (runtime.Object, error) {
 	list := lw.newListFunc()
-	if err := lw.storage.List(lw.resourcePrefix, Everything, list); err != nil {
+	if err := lw.storage.List(context.TODO(), lw.resourcePrefix, Everything, list); err != nil {
 		return nil, err
 	}
 	return list, nil
@@ -355,7 +356,7 @@ func (lw *cacherListerWatcher) Watch(resourceVersion string) (watch.Interface, e
 	if err != nil {
 		return nil, err
 	}
-	return lw.storage.WatchList(lw.resourcePrefix, version, Everything)
+	return lw.storage.WatchList(context.TODO(), lw.resourcePrefix, version, Everything)
 }
 
 // cacherWatch implements watch.Interface

pkg/storage/cacher_test.go

@@ -39,6 +39,8 @@ import (
 	"k8s.io/kubernetes/pkg/util/sets"
 	"k8s.io/kubernetes/pkg/util/wait"
 	"k8s.io/kubernetes/pkg/watch"
+
+	"golang.org/x/net/context"
 )
 
 func newTestCacher(client tools.EtcdClient) *storage.Cacher {
@@ -250,7 +252,7 @@ func TestWatch(t *testing.T) {
 	}
 
 	// Set up Watch for object "podFoo".
-	watcher, err := cacher.Watch("pods/ns/foo", 2, storage.Everything)
+	watcher, err := cacher.Watch(context.TODO(), "pods/ns/foo", 2, storage.Everything)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
@@ -273,13 +275,13 @@ func TestWatch(t *testing.T) {
 	}
 
 	// Check whether we get too-old error.
-	_, err = cacher.Watch("pods/ns/foo", 1, storage.Everything)
+	_, err = cacher.Watch(context.TODO(), "pods/ns/foo", 1, storage.Everything)
 	if err == nil {
 		t.Errorf("exepcted 'error too old' error")
 	}
 
 	// Now test watch with initial state.
-	initialWatcher, err := cacher.Watch("pods/ns/foo", 2, storage.Everything)
+	initialWatcher, err := cacher.Watch(context.TODO(), "pods/ns/foo", 2, storage.Everything)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
@@ -300,7 +302,7 @@ func TestWatch(t *testing.T) {
 	}
 
 	// Now test watch from "now".
-	nowWatcher, err := cacher.Watch("pods/ns/foo", 0, storage.Everything)
+	nowWatcher, err := cacher.Watch(context.TODO(), "pods/ns/foo", 0, storage.Everything)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
@@ -450,7 +452,7 @@ func TestFiltering(t *testing.T) {
 		}
 		return selector.Matches(labels.Set(metadata.Labels()))
 	}
-	watcher, err := cacher.Watch("pods/ns/foo", 1, filter)
+	watcher, err := cacher.Watch(context.TODO(), "pods/ns/foo", 1, filter)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
@@ -485,7 +487,7 @@ func TestStorageError(t *testing.T) {
 	podFoo := makeTestPod("foo")
 
 	// Set up Watch for object "podFoo".
-	watcher, err := cacher.Watch("pods/ns/foo", 1, storage.Everything)
+	watcher, err := cacher.Watch(context.TODO(), "pods/ns/foo", 1, storage.Everything)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}

pkg/storage/etcd/etcd_helper.go

@@ -35,6 +35,7 @@ import (
 	"k8s.io/kubernetes/pkg/watch"
 
 	"github.com/golang/glog"
+	"golang.org/x/net/context"
 )
 
 func NewEtcdStorage(client tools.EtcdClient, codec runtime.Codec, prefix string) storage.Interface {
@@ -78,7 +79,10 @@ func (h *etcdHelper) Codec() runtime.Codec {
 }
 
 // Implements storage.Interface.
-func (h *etcdHelper) Backends() []string {
+func (h *etcdHelper) Backends(ctx context.Context) []string {
+	if ctx == nil {
+		glog.Errorf("Context is nil")
+	}
 	return h.client.GetCluster()
 }
 
@@ -88,7 +92,10 @@ func (h *etcdHelper) Versioner() storage.Versioner {
 }
 
 // Implements storage.Interface.
-func (h *etcdHelper) Create(key string, obj, out runtime.Object, ttl uint64) error {
+func (h *etcdHelper) Create(ctx context.Context, key string, obj, out runtime.Object, ttl uint64) error {
+	if ctx == nil {
+		glog.Errorf("Context is nil")
+	}
 	key = h.prefixEtcdKey(key)
 	data, err := h.codec.Encode(obj)
 	if err != nil {
@@ -116,7 +123,10 @@ func (h *etcdHelper) Create(key string, obj, out runtime.Object, ttl uint64) err
 }
 
 // Implements storage.Interface.
-func (h *etcdHelper) Set(key string, obj, out runtime.Object, ttl uint64) error {
+func (h *etcdHelper) Set(ctx context.Context, key string, obj, out runtime.Object, ttl uint64) error {
+	if ctx == nil {
+		glog.Errorf("Context is nil")
+	}
 	var response *etcd.Response
 	data, err := h.codec.Encode(obj)
 	if err != nil {
@@ -157,7 +167,10 @@ func (h *etcdHelper) Set(key string, obj, out runtime.Object, ttl uint64) error
 }
 
 // Implements storage.Interface.
-func (h *etcdHelper) Delete(key string, out runtime.Object) error {
+func (h *etcdHelper) Delete(ctx context.Context, key string, out runtime.Object) error {
+	if ctx == nil {
+		glog.Errorf("Context is nil")
+	}
 	key = h.prefixEtcdKey(key)
 	if _, err := conversion.EnforcePtr(out); err != nil {
 		panic("unable to convert output object to pointer")
@@ -176,7 +189,10 @@ func (h *etcdHelper) Delete(key string, out runtime.Object) error {
 }
 
 // Implements storage.Interface.
-func (h *etcdHelper) Watch(key string, resourceVersion uint64, filter storage.FilterFunc) (watch.Interface, error) {
+func (h *etcdHelper) Watch(ctx context.Context, key string, resourceVersion uint64, filter storage.FilterFunc) (watch.Interface, error) {
+	if ctx == nil {
+		glog.Errorf("Context is nil")
+	}
 	key = h.prefixEtcdKey(key)
 	w := newEtcdWatcher(false, nil, filter, h.codec, h.versioner, nil, h)
 	go w.etcdWatch(h.client, key, resourceVersion)
@@ -184,7 +200,10 @@ func (h *etcdHelper) Watch(key string, resourceVersion uint64, filter storage.Fi
 }
 
 // Implements storage.Interface.
-func (h *etcdHelper) WatchList(key string, resourceVersion uint64, filter storage.FilterFunc) (watch.Interface, error) {
+func (h *etcdHelper) WatchList(ctx context.Context, key string, resourceVersion uint64, filter storage.FilterFunc) (watch.Interface, error) {
+	if ctx == nil {
+		glog.Errorf("Context is nil")
+	}
 	key = h.prefixEtcdKey(key)
 	w := newEtcdWatcher(true, exceptKey(key), filter, h.codec, h.versioner, nil, h)
 	go w.etcdWatch(h.client, key, resourceVersion)
@@ -192,15 +211,21 @@ func (h *etcdHelper) WatchList(key string, resourceVersion uint64, filter storag
 }
 
 // Implements storage.Interface.
-func (h *etcdHelper) Get(key string, objPtr runtime.Object, ignoreNotFound bool) error {
+func (h *etcdHelper) Get(ctx context.Context, key string, objPtr runtime.Object, ignoreNotFound bool) error {
+	if ctx == nil {
+		glog.Errorf("Context is nil")
+	}
 	key = h.prefixEtcdKey(key)
-	_, _, _, err := h.bodyAndExtractObj(key, objPtr, ignoreNotFound)
+	_, _, _, err := h.bodyAndExtractObj(ctx, key, objPtr, ignoreNotFound)
 	return err
 }
 
 // bodyAndExtractObj performs the normal Get path to etcd, returning the parsed node and response for additional information
 // about the response, like the current etcd index and the ttl.
-func (h *etcdHelper) bodyAndExtractObj(key string, objPtr runtime.Object, ignoreNotFound bool) (body string, node *etcd.Node, res *etcd.Response, err error) {
+func (h *etcdHelper) bodyAndExtractObj(ctx context.Context, key string, objPtr runtime.Object, ignoreNotFound bool) (body string, node *etcd.Node, res *etcd.Response, err error) {
+	if ctx == nil {
+		glog.Errorf("Context is nil")
+	}
 	startTime := time.Now()
 	response, err := h.client.Get(key, false, false)
 	metrics.RecordEtcdRequestLatency("get", getTypeName(objPtr), startTime)
@@ -243,7 +268,10 @@ func (h *etcdHelper) extractObj(response *etcd.Response, inErr error, objPtr run
 }
 
 // Implements storage.Interface.
-func (h *etcdHelper) GetToList(key string, filter storage.FilterFunc, listObj runtime.Object) error {
+func (h *etcdHelper) GetToList(ctx context.Context, key string, filter storage.FilterFunc, listObj runtime.Object) error {
+	if ctx == nil {
+		glog.Errorf("Context is nil")
+	}
 	trace := util.NewTrace("GetToList " + getTypeName(listObj))
 	listPtr, err := runtime.GetItemsPtr(listObj)
 	if err != nil {
@@ -321,7 +349,10 @@ func (h *etcdHelper) decodeNodeList(nodes []*etcd.Node, filter storage.FilterFun
 }
 
 // Implements storage.Interface.
-func (h *etcdHelper) List(key string, filter storage.FilterFunc, listObj runtime.Object) error {
+func (h *etcdHelper) List(ctx context.Context, key string, filter storage.FilterFunc, listObj runtime.Object) error {
+	if ctx == nil {
+		glog.Errorf("Context is nil")
+	}
 	trace := util.NewTrace("List " + getTypeName(listObj))
 	defer trace.LogIfLong(time.Second)
 	listPtr, err := runtime.GetItemsPtr(listObj)
@@ -331,7 +362,7 @@ func (h *etcdHelper) List(key string, filter storage.FilterFunc, listObj runtime
 	key = h.prefixEtcdKey(key)
 	startTime := time.Now()
 	trace.Step("About to list etcd node")
-	nodes, index, err := h.listEtcdNode(key)
+	nodes, index, err := h.listEtcdNode(ctx, key)
 	metrics.RecordEtcdRequestLatency("list", getTypeName(listPtr), startTime)
 	trace.Step("Etcd node listed")
 	if err != nil {
@@ -349,7 +380,10 @@ func (h *etcdHelper) List(key string, filter storage.FilterFunc, listObj runtime
 	return nil
 }
 
-func (h *etcdHelper) listEtcdNode(key string) ([]*etcd.Node, uint64, error) {
+func (h *etcdHelper) listEtcdNode(ctx context.Context, key string) ([]*etcd.Node, uint64, error) {
+	if ctx == nil {
+		glog.Errorf("Context is nil")
+	}
 	result, err := h.client.Get(key, true, true)
 	if err != nil {
 		index, ok := etcdErrorIndex(err)
@@ -367,7 +401,10 @@ func (h *etcdHelper) listEtcdNode(key string) ([]*etcd.Node, uint64, error) {
 }
 
 // Implements storage.Interface.
-func (h *etcdHelper) GuaranteedUpdate(key string, ptrToType runtime.Object, ignoreNotFound bool, tryUpdate storage.UpdateFunc) error {
+func (h *etcdHelper) GuaranteedUpdate(ctx context.Context, key string, ptrToType runtime.Object, ignoreNotFound bool, tryUpdate storage.UpdateFunc) error {
+	if ctx == nil {
+		glog.Errorf("Context is nil")
+	}
 	v, err := conversion.EnforcePtr(ptrToType)
 	if err != nil {
 		// Panic is appropriate, because this is a programming error.
@@ -376,7 +413,7 @@ func (h *etcdHelper) GuaranteedUpdate(key string, ptrToType runtime.Object, igno
 	key = h.prefixEtcdKey(key)
 	for {
 		obj := reflect.New(v.Type()).Interface().(runtime.Object)
-		origBody, node, res, err := h.bodyAndExtractObj(key, obj, ignoreNotFound)
+		origBody, node, res, err := h.bodyAndExtractObj(ctx, key, obj, ignoreNotFound)
 		if err != nil {
 			return err
 		}

pkg/storage/etcd/etcd_helper_test.go

@@ -32,6 +32,7 @@ import (
 
 	"github.com/coreos/go-etcd/etcd"
 	"github.com/stretchr/testify/assert"
+	"golang.org/x/net/context"
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/api/testapi"
 	apitesting "k8s.io/kubernetes/pkg/api/testing"
@@ -144,7 +145,7 @@ func TestList(t *testing.T) {
 	}
 
 	var got api.PodList
-	err := helper.List("/some/key", storage.Everything, &got)
+	err := helper.List(context.TODO(), "/some/key", storage.Everything, &got)
 	if err != nil {
 		t.Errorf("Unexpected error %v", err)
 	}
@@ -201,7 +202,7 @@ func TestListFiltered(t *testing.T) {
 	}
 
 	var got api.PodList
-	err := helper.List("/some/key", filter, &got)
+	err := helper.List(context.TODO(), "/some/key", filter, &got)
 	if err != nil {
 		t.Errorf("Unexpected error %v", err)
 	}
@@ -276,7 +277,7 @@ func TestListAcrossDirectories(t *testing.T) {
 	}
 
 	var got api.PodList
-	err := helper.List("/some/key", storage.Everything, &got)
+	err := helper.List(context.TODO(), "/some/key", storage.Everything, &got)
 	if err != nil {
 		t.Errorf("Unexpected error %v", err)
 	}
@@ -338,7 +339,7 @@ func TestListExcludesDirectories(t *testing.T) {
 	}
 
 	var got api.PodList
-	err := helper.List("/some/key", storage.Everything, &got)
+	err := helper.List(context.TODO(), "/some/key", storage.Everything, &got)
 	if err != nil {
 		t.Errorf("Unexpected error %v", err)
 	}
@@ -357,7 +358,7 @@ func TestGet(t *testing.T) {
 	}
 	fakeClient.Set(key, runtime.EncodeOrDie(testapi.Default.Codec(), &expect), 0)
 	var got api.Pod
-	err := helper.Get("/some/key", &got, false)
+	err := helper.Get(context.TODO(), "/some/key", &got, false)
 	if err != nil {
 		t.Errorf("Unexpected error %#v", err)
 	}
@@ -394,11 +395,11 @@ func TestGetNotFoundErr(t *testing.T) {
 	}
 	try := func(key string) {
 		var got api.Pod
-		err := helper.Get(key, &got, false)
+		err := helper.Get(context.TODO(), key, &got, false)
 		if err == nil {
 			t.Errorf("%s: wanted error but didn't get one", key)
 		}
-		err = helper.Get(key, &got, true)
+		err = helper.Get(context.TODO(), key, &got, true)
 		if err != nil {
 			t.Errorf("%s: didn't want error but got %#v", key, err)
 		}
@@ -414,7 +415,7 @@ func TestCreate(t *testing.T) {
 	fakeClient := tools.NewFakeEtcdClient(t)
 	helper := newEtcdHelper(fakeClient, testapi.Default.Codec(), etcdtest.PathPrefix())
 	returnedObj := &api.Pod{}
-	err := helper.Create("/some/key", obj, returnedObj, 5)
+	err := helper.Create(context.TODO(), "/some/key", obj, returnedObj, 5)
 	if err != nil {
 		t.Errorf("Unexpected error %#v", err)
 	}
@@ -439,7 +440,7 @@ func TestCreateNilOutParam(t *testing.T) {
 	obj := &api.Pod{ObjectMeta: api.ObjectMeta{Name: "foo"}}
 	fakeClient := tools.NewFakeEtcdClient(t)
 	helper := newEtcdHelper(fakeClient, testapi.Default.Codec(), etcdtest.PathPrefix())
-	err := helper.Create("/some/key", obj, nil, 5)
+	err := helper.Create(context.TODO(), "/some/key", obj, nil, 5)
 	if err != nil {
 		t.Errorf("Unexpected error %#v", err)
 	}
@@ -450,7 +451,7 @@ func TestSet(t *testing.T) {
 	fakeClient := tools.NewFakeEtcdClient(t)
 	helper := newEtcdHelper(fakeClient, testapi.Default.Codec(), etcdtest.PathPrefix())
 	returnedObj := &api.Pod{}
-	err := helper.Set("/some/key", obj, returnedObj, 5)
+	err := helper.Set(context.TODO(), "/some/key", obj, returnedObj, 5)
 	if err != nil {
 		t.Errorf("Unexpected error %#v", err)
 	}
@@ -477,7 +478,7 @@ func TestSetFailCAS(t *testing.T) {
 	fakeClient := tools.NewFakeEtcdClient(t)
 	fakeClient.CasErr = fakeClient.NewError(123)
 	helper := newEtcdHelper(fakeClient, testapi.Default.Codec(), etcdtest.PathPrefix())
-	err := helper.Set("/some/key", obj, nil, 5)
+	err := helper.Set(context.TODO(), "/some/key", obj, nil, 5)
 	if err == nil {
 		t.Errorf("Expecting error.")
 	}
@@ -499,7 +500,7 @@ func TestSetWithVersion(t *testing.T) {
 	}
 
 	returnedObj := &api.Pod{}
-	err := helper.Set("/some/key", obj, returnedObj, 7)
+	err := helper.Set(context.TODO(), "/some/key", obj, returnedObj, 7)
 	if err != nil {
 		t.Fatalf("Unexpected error %#v", err)
 	}
@@ -526,7 +527,7 @@ func TestSetWithoutResourceVersioner(t *testing.T) {
 	helper := newEtcdHelper(fakeClient, testapi.Default.Codec(), etcdtest.PathPrefix())
 	helper.versioner = nil
 	returnedObj := &api.Pod{}
-	err := helper.Set("/some/key", obj, returnedObj, 3)
+	err := helper.Set(context.TODO(), "/some/key", obj, returnedObj, 3)
 	key := etcdtest.AddPrefix("/some/key")
 	if err != nil {
 		t.Errorf("Unexpected error %#v", err)
@@ -553,7 +554,7 @@ func TestSetNilOutParam(t *testing.T) {
 	fakeClient := tools.NewFakeEtcdClient(t)
 	helper := newEtcdHelper(fakeClient, testapi.Default.Codec(), etcdtest.PathPrefix())
 	helper.versioner = nil
-	err := helper.Set("/some/key", obj, nil, 3)
+	err := helper.Set(context.TODO(), "/some/key", obj, nil, 3)
 	if err != nil {
 		t.Errorf("Unexpected error %#v", err)
 	}
@@ -568,7 +569,7 @@ func TestGuaranteedUpdate(t *testing.T) {
 	// Create a new node.
 	fakeClient.ExpectNotFoundGet(key)
 	obj := &TestResource{ObjectMeta: api.ObjectMeta{Name: "foo"}, Value: 1}
-	err := helper.GuaranteedUpdate("/some/key", &TestResource{}, true, storage.SimpleUpdate(func(in runtime.Object) (runtime.Object, error) {
+	err := helper.GuaranteedUpdate(context.TODO(), "/some/key", &TestResource{}, true, storage.SimpleUpdate(func(in runtime.Object) (runtime.Object, error) {
 		return obj, nil
 	}))
 	if err != nil {
@@ -587,7 +588,7 @@ func TestGuaranteedUpdate(t *testing.T) {
 	// Update an existing node.
 	callbackCalled := false
 	objUpdate := &TestResource{ObjectMeta: api.ObjectMeta{Name: "foo"}, Value: 2}
-	err = helper.GuaranteedUpdate("/some/key", &TestResource{}, true, storage.SimpleUpdate(func(in runtime.Object) (runtime.Object, error) {
+	err = helper.GuaranteedUpdate(context.TODO(), "/some/key", &TestResource{}, true, storage.SimpleUpdate(func(in runtime.Object) (runtime.Object, error) {
 		callbackCalled = true
 
 		if in.(*TestResource).Value != 1 {
@@ -623,7 +624,7 @@ func TestGuaranteedUpdateTTL(t *testing.T) {
 	// Create a new node.
 	fakeClient.ExpectNotFoundGet(key)
 	obj := &TestResource{ObjectMeta: api.ObjectMeta{Name: "foo"}, Value: 1}
-	err := helper.GuaranteedUpdate("/some/key", &TestResource{}, true, func(in runtime.Object, res storage.ResponseMeta) (runtime.Object, *uint64, error) {
+	err := helper.GuaranteedUpdate(context.TODO(), "/some/key", &TestResource{}, true, func(in runtime.Object, res storage.ResponseMeta) (runtime.Object, *uint64, error) {
 		if res.TTL != 0 {
 			t.Fatalf("unexpected response meta: %#v", res)
 		}
@@ -649,7 +650,7 @@ func TestGuaranteedUpdateTTL(t *testing.T) {
 	// Update an existing node.
 	callbackCalled := false
 	objUpdate := &TestResource{ObjectMeta: api.ObjectMeta{Name: "foo"}, Value: 2}
-	err = helper.GuaranteedUpdate("/some/key", &TestResource{}, true, func(in runtime.Object, res storage.ResponseMeta) (runtime.Object, *uint64, error) {
+	err = helper.GuaranteedUpdate(context.TODO(), "/some/key", &TestResource{}, true, func(in runtime.Object, res storage.ResponseMeta) (runtime.Object, *uint64, error) {
 		if res.TTL != 10 {
 			t.Fatalf("unexpected response meta: %#v", res)
 		}
@@ -681,7 +682,7 @@ func TestGuaranteedUpdateTTL(t *testing.T) {
 	// Update an existing node and change ttl
 	callbackCalled = false
 	objUpdate = &TestResource{ObjectMeta: api.ObjectMeta{Name: "foo"}, Value: 3}
-	err = helper.GuaranteedUpdate("/some/key", &TestResource{}, true, func(in runtime.Object, res storage.ResponseMeta) (runtime.Object, *uint64, error) {
+	err = helper.GuaranteedUpdate(context.TODO(), "/some/key", &TestResource{}, true, func(in runtime.Object, res storage.ResponseMeta) (runtime.Object, *uint64, error) {
 		if res.TTL != 10 {
 			t.Fatalf("unexpected response meta: %#v", res)
 		}
@@ -724,7 +725,7 @@ func TestGuaranteedUpdateNoChange(t *testing.T) {
 	// Create a new node.
 	fakeClient.ExpectNotFoundGet(key)
 	obj := &TestResource{ObjectMeta: api.ObjectMeta{Name: "foo"}, Value: 1}
-	err := helper.GuaranteedUpdate("/some/key", &TestResource{}, true, storage.SimpleUpdate(func(in runtime.Object) (runtime.Object, error) {
+	err := helper.GuaranteedUpdate(context.TODO(), "/some/key", &TestResource{}, true, storage.SimpleUpdate(func(in runtime.Object) (runtime.Object, error) {
 		return obj, nil
 	}))
 	if err != nil {
@@ -734,7 +735,7 @@ func TestGuaranteedUpdateNoChange(t *testing.T) {
 	// Update an existing node with the same data
 	callbackCalled := false
 	objUpdate := &TestResource{ObjectMeta: api.ObjectMeta{Name: "foo"}, Value: 1}
-	err = helper.GuaranteedUpdate("/some/key", &TestResource{}, true, storage.SimpleUpdate(func(in runtime.Object) (runtime.Object, error) {
+	err = helper.GuaranteedUpdate(context.TODO(), "/some/key", &TestResource{}, true, storage.SimpleUpdate(func(in runtime.Object) (runtime.Object, error) {
 		fakeClient.Err = errors.New("should not be called")
 		callbackCalled = true
 		return objUpdate, nil
@@ -762,13 +763,13 @@ func TestGuaranteedUpdateKeyNotFound(t *testing.T) {
 	})
 
 	ignoreNotFound := false
-	err := helper.GuaranteedUpdate("/some/key", &TestResource{}, ignoreNotFound, f)
+	err := helper.GuaranteedUpdate(context.TODO(), "/some/key", &TestResource{}, ignoreNotFound, f)
 	if err == nil {
 		t.Errorf("Expected error for key not found.")
 	}
 
 	ignoreNotFound = true
-	err = helper.GuaranteedUpdate("/some/key", &TestResource{}, ignoreNotFound, f)
+	err = helper.GuaranteedUpdate(context.TODO(), "/some/key", &TestResource{}, ignoreNotFound, f)
 	if err != nil {
 		t.Errorf("Unexpected error %v.", err)
 	}
@@ -794,7 +795,7 @@ func TestGuaranteedUpdate_CreateCollision(t *testing.T) {
 			defer wgDone.Done()
 
 			firstCall := true
-			err := helper.GuaranteedUpdate("/some/key", &TestResource{}, true, storage.SimpleUpdate(func(in runtime.Object) (runtime.Object, error) {
+			err := helper.GuaranteedUpdate(context.TODO(), "/some/key", &TestResource{}, true, storage.SimpleUpdate(func(in runtime.Object) (runtime.Object, error) {
 				defer func() { firstCall = false }()
 
 				if firstCall {

pkg/storage/etcd/etcd_watcher_test.go

@@ -31,6 +31,8 @@ import (
 	"k8s.io/kubernetes/pkg/tools/etcdtest"
 	"k8s.io/kubernetes/pkg/util"
 	"k8s.io/kubernetes/pkg/watch"
+
+	"golang.org/x/net/context"
 )
 
 var versioner = APIObjectVersioner{}
@@ -223,7 +225,7 @@ func TestWatchEtcdError(t *testing.T) {
 	fakeClient.WatchImmediateError = fmt.Errorf("immediate error")
 	h := newEtcdHelper(fakeClient, codec, etcdtest.PathPrefix())
 
-	watching, err := h.Watch("/some/key", 4, storage.Everything)
+	watching, err := h.Watch(context.TODO(), "/some/key", 4, storage.Everything)
 	if err != nil {
 		t.Fatalf("Unexpected error: %v", err)
 	}
@@ -253,7 +255,7 @@ func TestWatch(t *testing.T) {
 	fakeClient.ExpectNotFoundGet(prefixedKey)
 	h := newEtcdHelper(fakeClient, codec, etcdtest.PathPrefix())
 
-	watching, err := h.Watch(key, 0, storage.Everything)
+	watching, err := h.Watch(context.TODO(), key, 0, storage.Everything)
 	if err != nil {
 		t.Fatalf("Unexpected error: %v", err)
 	}
@@ -428,7 +430,7 @@ func TestWatchEtcdState(t *testing.T) {
 		}
 
 		h := newEtcdHelper(fakeClient, codec, etcdtest.PathPrefix())
-		watching, err := h.Watch(baseKey, testCase.From, storage.Everything)
+		watching, err := h.Watch(context.TODO(), baseKey, testCase.From, storage.Everything)
 		if err != nil {
 			t.Fatalf("Unexpected error: %v", err)
 		}
@@ -502,7 +504,7 @@ func TestWatchFromZeroIndex(t *testing.T) {
 		fakeClient.Data[prefixedKey] = testCase.Response
 		h := newEtcdHelper(fakeClient, codec, etcdtest.PathPrefix())
 
-		watching, err := h.Watch(key, 0, storage.Everything)
+		watching, err := h.Watch(context.TODO(), key, 0, storage.Everything)
 		if err != nil {
 			t.Fatalf("Unexpected error: %v", err)
 		}
@@ -563,7 +565,7 @@ func TestWatchListFromZeroIndex(t *testing.T) {
 	}
 	h := newEtcdHelper(fakeClient, codec, etcdtest.PathPrefix())
 
-	watching, err := h.WatchList(key, 0, storage.Everything)
+	watching, err := h.WatchList(context.TODO(), key, 0, storage.Everything)
 	if err != nil {
 		t.Fatalf("Unexpected error: %v", err)
 	}
@@ -603,7 +605,7 @@ func TestWatchListIgnoresRootKey(t *testing.T) {
 	fakeClient := tools.NewFakeEtcdClient(t)
 	h := newEtcdHelper(fakeClient, codec, etcdtest.PathPrefix())
 
-	watching, err := h.WatchList(key, 1, storage.Everything)
+	watching, err := h.WatchList(context.TODO(), key, 1, storage.Everything)
 	if err != nil {
 		t.Fatalf("Unexpected error: %v", err)
 	}
@@ -656,7 +658,7 @@ func TestWatchFromNotFound(t *testing.T) {
 	}
 	h := newEtcdHelper(fakeClient, codec, etcdtest.PathPrefix())
 
-	watching, err := h.Watch(key, 0, storage.Everything)
+	watching, err := h.Watch(context.TODO(), key, 0, storage.Everything)
 	if err != nil {
 		t.Fatalf("Unexpected error: %v", err)
 	}
@@ -683,7 +685,7 @@ func TestWatchFromOtherError(t *testing.T) {
 	}
 	h := newEtcdHelper(fakeClient, codec, etcdtest.PathPrefix())
 
-	watching, err := h.Watch(key, 0, storage.Everything)
+	watching, err := h.Watch(context.TODO(), key, 0, storage.Everything)
 	if err != nil {
 		t.Fatalf("Unexpected error: %v", err)
 	}
@@ -719,7 +721,7 @@ func TestWatchPurposefulShutdown(t *testing.T) {
 	fakeClient.ExpectNotFoundGet(prefixedKey)
 
 	// Test purposeful shutdown
-	watching, err := h.Watch(key, 0, storage.Everything)
+	watching, err := h.Watch(context.TODO(), key, 0, storage.Everything)
 	if err != nil {
 		t.Fatalf("Unexpected error: %v", err)
 	}

pkg/storage/interfaces.go

@@ -19,6 +19,7 @@ package storage
 import (
 	"time"
 
+	"golang.org/x/net/context"
 	"k8s.io/kubernetes/pkg/runtime"
 	"k8s.io/kubernetes/pkg/watch"
 )
@@ -74,7 +75,7 @@ type Interface interface {
 	// Returns list of servers addresses of the underyling database.
 	// TODO: This method is used only in a single place. Consider refactoring and getting rid
 	// of this method from the interface.
-	Backends() []string
+	Backends(ctx context.Context) []string
 
 	// Returns Versioner associated with this interface.
 	Versioner() Versioner
@@ -82,40 +83,40 @@ type Interface interface {
 	// Create adds a new object at a key unless it already exists. 'ttl' is time-to-live
 	// in seconds (0 means forever). If no error is returned and out is not nil, out will be
 	// set to the read value from database.
-	Create(key string, obj, out runtime.Object, ttl uint64) error
+	Create(ctx context.Context, key string, obj, out runtime.Object, ttl uint64) error
 
 	// Set marshals obj via json and stores in database under key. Will do an atomic update
 	// if obj's ResourceVersion field is set. 'ttl' is time-to-live in seconds (0 means forever).
 	// If no error is returned and out is not nil, out will be set to the read value from database.
-	Set(key string, obj, out runtime.Object, ttl uint64) error
+	Set(ctx context.Context, key string, obj, out runtime.Object, ttl uint64) error
 
 	// Delete removes the specified key and returns the value that existed at that spot.
-	Delete(key string, out runtime.Object) error
+	Delete(ctx context.Context, key string, out runtime.Object) error
 
 	// Watch begins watching the specified key. Events are decoded into API objects,
 	// and any items passing 'filter' are sent down to returned watch.Interface.
 	// resourceVersion may be used to specify what version to begin watching
 	// (e.g. reconnecting without missing any updates).
-	Watch(key string, resourceVersion uint64, filter FilterFunc) (watch.Interface, error)
+	Watch(ctx context.Context, key string, resourceVersion uint64, filter FilterFunc) (watch.Interface, error)
 
 	// WatchList begins watching the specified key's items. Items are decoded into API
 	// objects and any item passing 'filter' are sent down to returned watch.Interface.
 	// resourceVersion may be used to specify what version to begin watching
 	// (e.g. reconnecting without missing any updates).
-	WatchList(key string, resourceVersion uint64, filter FilterFunc) (watch.Interface, error)
+	WatchList(ctx context.Context, key string, resourceVersion uint64, filter FilterFunc) (watch.Interface, error)
 
 	// Get unmarshals json found at key into objPtr. On a not found error, will either
 	// return a zero object of the requested type, or an error, depending on ignoreNotFound.
 	// Treats empty responses and nil response nodes exactly like a not found error.
-	Get(key string, objPtr runtime.Object, ignoreNotFound bool) error
+	Get(ctx context.Context, key string, objPtr runtime.Object, ignoreNotFound bool) error
 
 	// GetToList unmarshals json found at key and opaque it into *List api object
 	// (an object that satisfies the runtime.IsList definition).
-	GetToList(key string, filter FilterFunc, listObj runtime.Object) error
+	GetToList(ctx context.Context, key string, filter FilterFunc, listObj runtime.Object) error
 
 	// List unmarshalls jsons found at directory defined by key and opaque them
 	// into *List api object (an object that satisfies runtime.IsList definition).
-	List(key string, filter FilterFunc, listObj runtime.Object) error
+	List(ctx context.Context, key string, filter FilterFunc, listObj runtime.Object) error
 
 	// GuaranteedUpdate keeps calling 'tryUpdate()' to update key 'key' (of type 'ptrToType')
 	// retrying the update until success if there is index conflict.
@@ -141,7 +142,7 @@ type Interface interface {
 	//       return cur, nil, nil
 	//    }
 	// })
-	GuaranteedUpdate(key string, ptrToType runtime.Object, ignoreNotFound bool, tryUpdate UpdateFunc) error
+	GuaranteedUpdate(ctx context.Context, key string, ptrToType runtime.Object, ignoreNotFound bool, tryUpdate UpdateFunc) error
 
 	// Codec provides access to the underlying codec being used by the implementation.
 	Codec() runtime.Codec

test/integration/etcd_tools_test.go

@@ -30,14 +30,17 @@ import (
 	"k8s.io/kubernetes/pkg/tools/etcdtest"
 	"k8s.io/kubernetes/pkg/watch"
 	"k8s.io/kubernetes/test/integration/framework"
+
+	"golang.org/x/net/context"
 )
 
 func TestSet(t *testing.T) {
 	client := framework.NewEtcdClient()
 	etcdStorage := etcd.NewEtcdStorage(client, testapi.Default.Codec(), "")
+	ctx := context.TODO()
 	framework.WithEtcdKey(func(key string) {
 		testObject := api.ServiceAccount{ObjectMeta: api.ObjectMeta{Name: "foo"}}
-		if err := etcdStorage.Set(key, &testObject, nil, 0); err != nil {
+		if err := etcdStorage.Set(ctx, key, &testObject, nil, 0); err != nil {
 			t.Fatalf("unexpected error: %v", err)
 		}
 		resp, err := client.Get(key, false, false)
@@ -58,6 +61,7 @@ func TestSet(t *testing.T) {
 func TestGet(t *testing.T) {
 	client := framework.NewEtcdClient()
 	etcdStorage := etcd.NewEtcdStorage(client, testapi.Default.Codec(), "")
+	ctx := context.TODO()
 	framework.WithEtcdKey(func(key string) {
 		testObject := api.ServiceAccount{ObjectMeta: api.ObjectMeta{Name: "foo"}}
 		coded, err := testapi.Default.Codec().Encode(&testObject)
@@ -69,7 +73,7 @@ func TestGet(t *testing.T) {
 			t.Fatalf("unexpected error: %v", err)
 		}
 		result := api.ServiceAccount{}
-		if err := etcdStorage.Get(key, &result, false); err != nil {
+		if err := etcdStorage.Get(ctx, key, &result, false); err != nil {
 			t.Fatalf("unexpected error: %v", err)
 		}
 		// Propagate ResourceVersion (it is set automatically).
@@ -83,13 +87,14 @@ func TestGet(t *testing.T) {
 func TestWriteTTL(t *testing.T) {
 	client := framework.NewEtcdClient()
 	etcdStorage := etcd.NewEtcdStorage(client, testapi.Default.Codec(), "")
+	ctx := context.TODO()
 	framework.WithEtcdKey(func(key string) {
 		testObject := api.ServiceAccount{ObjectMeta: api.ObjectMeta{Name: "foo"}}
-		if err := etcdStorage.Set(key, &testObject, nil, 0); err != nil {
+		if err := etcdStorage.Set(ctx, key, &testObject, nil, 0); err != nil {
 			t.Fatalf("unexpected error: %v", err)
 		}
 		result := &api.ServiceAccount{}
-		err := etcdStorage.GuaranteedUpdate(key, result, false, func(obj runtime.Object, res storage.ResponseMeta) (runtime.Object, *uint64, error) {
+		err := etcdStorage.GuaranteedUpdate(ctx, key, result, false, func(obj runtime.Object, res storage.ResponseMeta) (runtime.Object, *uint64, error) {
 			if in, ok := obj.(*api.ServiceAccount); !ok || in.Name != "foo" {
 				t.Fatalf("unexpected existing object: %v", obj)
 			}
@@ -111,7 +116,7 @@ func TestWriteTTL(t *testing.T) {
 		}
 
 		result = &api.ServiceAccount{}
-		err = etcdStorage.GuaranteedUpdate(key, result, false, func(obj runtime.Object, res storage.ResponseMeta) (runtime.Object, *uint64, error) {
+		err = etcdStorage.GuaranteedUpdate(ctx, key, result, false, func(obj runtime.Object, res storage.ResponseMeta) (runtime.Object, *uint64, error) {
 			if in, ok := obj.(*api.ServiceAccount); !ok || in.Name != "out" {
 				t.Fatalf("unexpected existing object: %v", obj)
 			}
@@ -136,6 +141,7 @@ func TestWriteTTL(t *testing.T) {
 func TestWatch(t *testing.T) {
 	client := framework.NewEtcdClient()
 	etcdStorage := etcd.NewEtcdStorage(client, testapi.Default.Codec(), etcdtest.PathPrefix())
+	ctx := context.TODO()
 	framework.WithEtcdKey(func(key string) {
 		key = etcdtest.AddPrefix(key)
 		resp, err := client.Set(key, runtime.EncodeOrDie(testapi.Default.Codec(), &api.Pod{ObjectMeta: api.ObjectMeta{Name: "foo"}}), 0)
@@ -145,7 +151,7 @@ func TestWatch(t *testing.T) {
 		expectedVersion := resp.Node.ModifiedIndex
 
 		// watch should load the object at the current index
-		w, err := etcdStorage.Watch(key, 0, storage.Everything)
+		w, err := etcdStorage.Watch(ctx, key, 0, storage.Everything)
 		if err != nil {
 			t.Fatalf("Unexpected error: %v", err)
 		}