Make ListWatch work with a ListFunc and WatchFunc

pkg/client/cache/listwatch.go

@@ -23,33 +23,37 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/watch"
 )
 
+// ListFunc knows how to list resources
+type ListFunc func() (runtime.Object, error)
+
+// WatchFunc knows how to watch resources
+type WatchFunc func(resourceVersion string) (watch.Interface, error)
+
 // ListWatch knows how to list and watch a set of apiserver resources.  It satisfies the ListerWatcher interface.
-// It is a convenience function for users of NewReflector, etc.  Client must not be nil.
+// It is a convenience function for users of NewReflector, etc.
+// ListFunc and WatchFunc must not be nil
 type ListWatch struct {
-	Client        *client.Client
-	FieldSelector labels.Selector
-	Resource      string
-	Namespace     string
+	ListFunc  ListFunc
+	WatchFunc WatchFunc
+}
+
+// ListWatchFromClient creates a new ListWatch from the specified client, resource, namespace and field selector
+func NewListWatchFromClient(client *client.Client, resource string, namespace string, fieldSelector labels.Selector) *ListWatch {
+	listFunc := func() (runtime.Object, error) {
+		return client.Get().Namespace(namespace).Resource(resource).SelectorParam("fields", fieldSelector).Do().Get()
+	}
+	watchFunc := func(resourceVersion string) (watch.Interface, error) {
+		return client.Get().Prefix("watch").Namespace(namespace).Resource(resource).SelectorParam("fields", fieldSelector).Param("resourceVersion", resourceVersion).Watch()
+	}
+	return &ListWatch{ListFunc: listFunc, WatchFunc: watchFunc}
 }
 
-// ListWatch knows how to list and watch a set of apiserver resources.
+// List a set of apiserver resources
 func (lw *ListWatch) List() (runtime.Object, error) {
-	return lw.Client.
-		Get().
-		Namespace(lw.Namespace).
-		Resource(lw.Resource).
-		SelectorParam("fields", lw.FieldSelector).
-		Do().
-		Get()
+	return lw.ListFunc()
 }
 
+// Watch a set of apiserver resources
 func (lw *ListWatch) Watch(resourceVersion string) (watch.Interface, error) {
-	return lw.Client.
-		Get().
-		Prefix("watch").
-		Namespace(lw.Namespace).
-		Resource(lw.Resource).
-		SelectorParam("fields", lw.FieldSelector).
-		Param("resourceVersion", resourceVersion).
-		Watch()
+	return lw.WatchFunc(resourceVersion)
 }

pkg/client/cache/listwatch_test.go

@@ -72,33 +72,31 @@ func buildLocation(resourcePath string, query url.Values) string {
 
 func TestListWatchesCanList(t *testing.T) {
 	table := []struct {
-		location string
-		lw       ListWatch
+		location      string
+		resource      string
+		namespace     string
+		fieldSelector labels.Selector
 	}{
 		// Minion
 		{
-			location: buildLocation(buildResourcePath("", api.NamespaceAll, "minions"), buildQueryValues(api.NamespaceAll, nil)),
-			lw: ListWatch{
-				FieldSelector: parseSelectorOrDie(""),
-				Resource:      "minions",
-			},
+			location:      buildLocation(buildResourcePath("", api.NamespaceAll, "minions"), buildQueryValues(api.NamespaceAll, nil)),
+			resource:      "minions",
+			namespace:     api.NamespaceAll,
+			fieldSelector: parseSelectorOrDie(""),
 		},
 		// pod with "assigned" field selector.
 		{
-			location: buildLocation(buildResourcePath("", api.NamespaceAll, "pods"), buildQueryValues(api.NamespaceAll, url.Values{"fields": []string{"DesiredState.Host="}})),
-			lw: ListWatch{
-				FieldSelector: labels.Set{"DesiredState.Host": ""}.AsSelector(),
-				Resource:      "pods",
-			},
+			location:      buildLocation(buildResourcePath("", api.NamespaceAll, "pods"), buildQueryValues(api.NamespaceAll, url.Values{"fields": []string{"DesiredState.Host="}})),
+			resource:      "pods",
+			namespace:     api.NamespaceAll,
+			fieldSelector: labels.Set{"DesiredState.Host": ""}.AsSelector(),
 		},
 		// pod in namespace "foo"
 		{
-			location: buildLocation(buildResourcePath("", "foo", "pods"), buildQueryValues("foo", url.Values{"fields": []string{"DesiredState.Host="}})),
-			lw: ListWatch{
-				FieldSelector: labels.Set{"DesiredState.Host": ""}.AsSelector(),
-				Resource:      "pods",
-				Namespace:     "foo",
-			},
+			location:      buildLocation(buildResourcePath("", "foo", "pods"), buildQueryValues("foo", url.Values{"fields": []string{"DesiredState.Host="}})),
+			resource:      "pods",
+			namespace:     "foo",
+			fieldSelector: labels.Set{"DesiredState.Host": ""}.AsSelector(),
 		},
 	}
 	for _, item := range table {
@@ -109,54 +107,52 @@ func TestListWatchesCanList(t *testing.T) {
 		}
 		server := httptest.NewServer(&handler)
 		defer server.Close()
-		item.lw.Client = client.NewOrDie(&client.Config{Host: server.URL, Version: testapi.Version()})
+		client := client.NewOrDie(&client.Config{Host: server.URL, Version: testapi.Version()})
+		lw := NewListWatchFromClient(client, item.resource, item.namespace, item.fieldSelector)
 		// This test merely tests that the correct request is made.
-		item.lw.List()
+		lw.List()
 		handler.ValidateRequest(t, item.location, "GET", nil)
 	}
 }
 
 func TestListWatchesCanWatch(t *testing.T) {
 	table := []struct {
-		rv       string
-		location string
-		lw       ListWatch
+		rv            string
+		location      string
+		resource      string
+		namespace     string
+		fieldSelector labels.Selector
 	}{
 		// Minion
 		{
-			location: buildLocation(buildResourcePath("watch", api.NamespaceAll, "minions"), buildQueryValues(api.NamespaceAll, url.Values{"resourceVersion": []string{""}})),
-			rv:       "",
-			lw: ListWatch{
-				FieldSelector: parseSelectorOrDie(""),
-				Resource:      "minions",
-			},
+			location:      buildLocation(buildResourcePath("watch", api.NamespaceAll, "minions"), buildQueryValues(api.NamespaceAll, url.Values{"resourceVersion": []string{""}})),
+			rv:            "",
+			resource:      "minions",
+			namespace:     api.NamespaceAll,
+			fieldSelector: parseSelectorOrDie(""),
 		},
 		{
-			location: buildLocation(buildResourcePath("watch", api.NamespaceAll, "minions"), buildQueryValues(api.NamespaceAll, url.Values{"resourceVersion": []string{"42"}})),
-			rv:       "42",
-			lw: ListWatch{
-				FieldSelector: parseSelectorOrDie(""),
-				Resource:      "minions",
-			},
+			location:      buildLocation(buildResourcePath("watch", api.NamespaceAll, "minions"), buildQueryValues(api.NamespaceAll, url.Values{"resourceVersion": []string{"42"}})),
+			rv:            "42",
+			resource:      "minions",
+			namespace:     api.NamespaceAll,
+			fieldSelector: parseSelectorOrDie(""),
 		},
 		// pod with "assigned" field selector.
 		{
-			location: buildLocation(buildResourcePath("watch", api.NamespaceAll, "pods"), buildQueryValues(api.NamespaceAll, url.Values{"fields": []string{"DesiredState.Host="}, "resourceVersion": []string{"0"}})),
-			rv:       "0",
-			lw: ListWatch{
-				FieldSelector: labels.Set{"DesiredState.Host": ""}.AsSelector(),
-				Resource:      "pods",
-			},
+			location:      buildLocation(buildResourcePath("watch", api.NamespaceAll, "pods"), buildQueryValues(api.NamespaceAll, url.Values{"fields": []string{"DesiredState.Host="}, "resourceVersion": []string{"0"}})),
+			rv:            "0",
+			resource:      "pods",
+			namespace:     api.NamespaceAll,
+			fieldSelector: labels.Set{"DesiredState.Host": ""}.AsSelector(),
 		},
 		// pod with namespace foo and assigned field selector
 		{
-			location: buildLocation(buildResourcePath("watch", "foo", "pods"), buildQueryValues("foo", url.Values{"fields": []string{"DesiredState.Host="}, "resourceVersion": []string{"0"}})),
-			rv:       "0",
-			lw: ListWatch{
-				FieldSelector: labels.Set{"DesiredState.Host": ""}.AsSelector(),
-				Resource:      "pods",
-				Namespace:     "foo",
-			},
+			location:      buildLocation(buildResourcePath("watch", "foo", "pods"), buildQueryValues("foo", url.Values{"fields": []string{"DesiredState.Host="}, "resourceVersion": []string{"0"}})),
+			rv:            "0",
+			resource:      "pods",
+			namespace:     "foo",
+			fieldSelector: labels.Set{"DesiredState.Host": ""}.AsSelector(),
 		},
 	}
 
@@ -168,10 +164,10 @@ func TestListWatchesCanWatch(t *testing.T) {
 		}
 		server := httptest.NewServer(&handler)
 		defer server.Close()
-		item.lw.Client = client.NewOrDie(&client.Config{Host: server.URL, Version: testapi.Version()})
-
+		client := client.NewOrDie(&client.Config{Host: server.URL, Version: testapi.Version()})
+		lw := NewListWatchFromClient(client, item.resource, item.namespace, item.fieldSelector)
 		// This test merely tests that the correct request is made.
-		item.lw.Watch(item.rv)
+		lw.Watch(item.rv)
 		handler.ValidateRequest(t, item.location, "GET", nil)
 	}
 }

pkg/kubelet/config/apiserver.go

@@ -28,11 +28,7 @@ import (
 
 // NewSourceApiserver creates a config source that watches and pulls from the apiserver.
 func NewSourceApiserver(client *client.Client, hostname string, updates chan<- interface{}) {
-	lw := &cache.ListWatch{
-		Client:        client,
-		FieldSelector: labels.OneTermEqualSelector("Status.Host", hostname),
-		Resource:      "pods",
-	}
+	lw := cache.NewListWatchFromClient(client, "pods", api.NamespaceAll, labels.OneTermEqualSelector("Status.Host", hostname))
 	newSourceApiserverFromLW(lw, updates)
 }
 

pkg/kubelet/kubelet.go

@@ -95,7 +95,7 @@ func NewMainKubelet(
 
 	serviceStore := cache.NewStore(cache.MetaNamespaceKeyFunc)
 	if kubeClient != nil {
-		cache.NewReflector(&cache.ListWatch{kubeClient, labels.Everything(), "services", api.NamespaceAll}, &api.Service{}, serviceStore).Run()
+		cache.NewReflector(cache.NewListWatchFromClient(kubeClient, "services", api.NamespaceAll, labels.Everything()), &api.Service{}, serviceStore).Run()
 	}
 	serviceLister := &cache.StoreToServiceLister{serviceStore}
 

plugin/pkg/admission/namespace/autoprovision/admission.go

@@ -26,6 +26,8 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/client"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/client/cache"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/labels"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/runtime"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/watch"
 )
 
 func init() {
@@ -79,9 +81,12 @@ func NewProvision(c client.Interface) admission.Interface {
 	store := cache.NewStore(cache.MetaNamespaceKeyFunc)
 	reflector := cache.NewReflector(
 		&cache.ListWatch{
-			Client:        c.(*client.Client),
-			FieldSelector: labels.Everything(),
-			Resource:      "namespaces",
+			ListFunc: func() (runtime.Object, error) {
+				return c.Namespaces().List(labels.Everything())
+			},
+			WatchFunc: func(resourceVersion string) (watch.Interface, error) {
+				return c.Namespaces().Watch(labels.Everything(), labels.Everything(), resourceVersion)
+			},
 		},
 		&api.Namespace{},
 		store,

plugin/pkg/admission/namespace/exists/admission.go

@@ -28,6 +28,8 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/client"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/client/cache"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/labels"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/runtime"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/watch"
 )
 
 func init() {
@@ -83,9 +85,12 @@ func NewExists(c client.Interface) admission.Interface {
 	// TODO: look into a list/watch that can work with client.Interface, maybe pass it a ListFunc and a WatchFunc
 	reflector := cache.NewReflector(
 		&cache.ListWatch{
-			Client:        c.(*client.Client),
-			FieldSelector: labels.Everything(),
-			Resource:      "namespaces",
+			ListFunc: func() (runtime.Object, error) {
+				return c.Namespaces().List(labels.Everything())
+			},
+			WatchFunc: func(resourceVersion string) (watch.Interface, error) {
+				return c.Namespaces().Watch(labels.Everything(), labels.Everything(), resourceVersion)
+			},
 		},
 		&api.Namespace{},
 		store,

plugin/pkg/scheduler/factory/factory.go

@@ -143,11 +143,7 @@ func (f *ConfigFactory) CreateFromKeys(predicateKeys, priorityKeys util.StringSe
 // createUnassignedPodLW returns a cache.ListWatch that finds all pods that need to be
 // scheduled.
 func (factory *ConfigFactory) createUnassignedPodLW() *cache.ListWatch {
-	return &cache.ListWatch{
-		Client:        factory.Client,
-		FieldSelector: labels.Set{"DesiredState.Host": ""}.AsSelector(),
-		Resource:      "pods",
-	}
+	return cache.NewListWatchFromClient(factory.Client, "pods", api.NamespaceAll, labels.Set{"DesiredState.Host": ""}.AsSelector())
 }
 
 func parseSelectorOrDie(s string) labels.Selector {
@@ -162,20 +158,12 @@ func parseSelectorOrDie(s string) labels.Selector {
 // already scheduled.
 // TODO: return a ListerWatcher interface instead?
 func (factory *ConfigFactory) createAssignedPodLW() *cache.ListWatch {
-	return &cache.ListWatch{
-		Client:        factory.Client,
-		FieldSelector: parseSelectorOrDie("DesiredState.Host!="),
-		Resource:      "pods",
-	}
+	return cache.NewListWatchFromClient(factory.Client, "pods", api.NamespaceAll, parseSelectorOrDie("DesiredState.Host!="))
 }
 
 // createMinionLW returns a cache.ListWatch that gets all changes to minions.
 func (factory *ConfigFactory) createMinionLW() *cache.ListWatch {
-	return &cache.ListWatch{
-		Client:        factory.Client,
-		FieldSelector: parseSelectorOrDie(""),
-		Resource:      "minions",
-	}
+	return cache.NewListWatchFromClient(factory.Client, "minions", api.NamespaceAll, parseSelectorOrDie(""))
 }
 
 // pollMinions lists all minions and filter out unhealthy ones, then returns
@@ -215,11 +203,7 @@ func (factory *ConfigFactory) pollMinions() (cache.Enumerator, error) {
 
 // createServiceLW returns a cache.ListWatch that gets all changes to services.
 func (factory *ConfigFactory) createServiceLW() *cache.ListWatch {
-	return &cache.ListWatch{
-		Client:        factory.Client,
-		FieldSelector: parseSelectorOrDie(""),
-		Resource:      "services",
-	}
+	return cache.NewListWatchFromClient(factory.Client, "services", api.NamespaceAll, parseSelectorOrDie(""))
 }
 
 func (factory *ConfigFactory) makeDefaultErrorFunc(backoff *podBackoff, podQueue *cache.FIFO) func(pod *api.Pod, err error) {