dynamic client: add support for API streaming

Kubernetes-commit: d778356bc6a057ae41bee4577e568293a25fce9b

dynamic/client_test.go

@@ -27,6 +27,8 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/google/go-cmp/cmp"
+
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 	"k8s.io/apimachinery/pkg/runtime"
@@ -34,6 +36,8 @@ import (
 	"k8s.io/apimachinery/pkg/runtime/serializer/streaming"
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/apimachinery/pkg/watch"
+	clientfeatures "k8s.io/client-go/features"
+	clientfeaturestesting "k8s.io/client-go/features/testing"
 	restclient "k8s.io/client-go/rest"
 	restclientwatch "k8s.io/client-go/rest/watch"
 )
@@ -148,6 +152,171 @@ func TestList(t *testing.T) {
 	}
 }
 
+func TestWatchList(t *testing.T) {
+	clientfeaturestesting.SetFeatureDuringTest(t, clientfeatures.WatchListClient, true)
+
+	type requestParam struct {
+		Path  string
+		Query string
+	}
+
+	scenarios := []struct {
+		name          string
+		namespace     string
+		watchResponse []watch.Event
+		listResponse  []byte
+
+		expectedRequestParams []requestParam
+		expectedList          *unstructured.UnstructuredList
+	}{
+		{
+			name: "watch-list request for cluster wide resource",
+			watchResponse: []watch.Event{
+				{Type: watch.Added, Object: getObject("gtest/vTest", "rTest", "item1")},
+				{Type: watch.Added, Object: getObject("gtest/vTest", "rTest", "item2")},
+				{Type: watch.Bookmark, Object: func() runtime.Object {
+					obj := getObject("gtest/vTest", "rTest", "item2")
+					obj.SetResourceVersion("10")
+					obj.SetAnnotations(map[string]string{metav1.InitialEventsAnnotationKey: "true"})
+					return obj
+				}()},
+			},
+			expectedRequestParams: []requestParam{
+				{
+					Path:  "/apis/gtest/vtest/rtest",
+					Query: "allowWatchBookmarks=true&resourceVersionMatch=NotOlderThan&sendInitialEvents=true&watch=true",
+				},
+			},
+			expectedList: &unstructured.UnstructuredList{
+				Object: map[string]interface{}{
+					"apiVersion": "",
+					"kind":       "UnstructuredList",
+					"metadata": map[string]interface{}{
+						"resourceVersion": "10",
+					},
+				},
+				Items: []unstructured.Unstructured{
+					*getObject("gtest/vTest", "rTest", "item1"),
+					*getObject("gtest/vTest", "rTest", "item2"),
+				},
+			},
+		},
+		{
+			name:      "watch-list request for namespaced watch resource",
+			namespace: "nstest",
+			watchResponse: []watch.Event{
+				{Type: watch.Added, Object: getObject("gtest/vTest", "rTest", "item1")},
+				{Type: watch.Bookmark, Object: func() runtime.Object {
+					obj := getObject("gtest/vTest", "rTest", "item2")
+					obj.SetResourceVersion("39")
+					obj.SetAnnotations(map[string]string{metav1.InitialEventsAnnotationKey: "true"})
+					return obj
+				}()},
+			},
+			expectedRequestParams: []requestParam{
+				{
+					Path:  "/apis/gtest/vtest/namespaces/nstest/rtest",
+					Query: "allowWatchBookmarks=true&resourceVersionMatch=NotOlderThan&sendInitialEvents=true&watch=true",
+				},
+			},
+			expectedList: &unstructured.UnstructuredList{
+				Object: map[string]interface{}{
+					"apiVersion": "",
+					"kind":       "UnstructuredList",
+					"metadata": map[string]interface{}{
+						"resourceVersion": "39",
+					},
+				},
+				Items: []unstructured.Unstructured{
+					*getObject("gtest/vTest", "rTest", "item1"),
+				},
+			},
+		},
+		{
+			name:      "watch-list request falls back to standard list on any error",
+			namespace: "nstest",
+			// watchList method in client-go expect only watch.Add and watch.Bookmark events
+			// receiving watch.Error will cause this method to report an error which will
+			// trigger the fallback logic
+			watchResponse: []watch.Event{
+				{Type: watch.Error, Object: getObject("gtest/vTest", "rTest", "item1")},
+			},
+			listResponse: getListJSON("vTest", "UnstructuredList",
+				getJSON("gtest/vTest", "rTest", "item1"),
+				getJSON("gtest/vTest", "rTest", "item2")),
+			expectedRequestParams: []requestParam{
+				// a watch-list request first
+				{
+					Path:  "/apis/gtest/vtest/namespaces/nstest/rtest",
+					Query: "allowWatchBookmarks=true&resourceVersionMatch=NotOlderThan&sendInitialEvents=true&watch=true",
+				},
+				// a standard list request second
+				{
+					Path: "/apis/gtest/vtest/namespaces/nstest/rtest",
+				},
+			},
+			expectedList: &unstructured.UnstructuredList{
+				Object: map[string]interface{}{
+					"apiVersion": "vTest",
+					"kind":       "UnstructuredList",
+				},
+				Items: []unstructured.Unstructured{
+					*getObject("gtest/vTest", "rTest", "item1"),
+					*getObject("gtest/vTest", "rTest", "item2"),
+				},
+			},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			var actualRequestParams []requestParam
+			resource := schema.GroupVersionResource{Group: "gtest", Version: "vtest", Resource: "rtest"}
+			cl, srv, err := getClientServer(func(w http.ResponseWriter, r *http.Request) {
+				if r.Method != "GET" {
+					t.Errorf("unexpected HTTP method %s. expected GET", r.Method)
+				}
+				actualRequestParams = append(actualRequestParams, requestParam{
+					Path:  r.URL.Path,
+					Query: r.URL.RawQuery,
+				})
+
+				w.Header().Set("Content-Type", runtime.ContentTypeJSON)
+				// handle LIST response
+				if len(scenario.listResponse) > 0 {
+					if _, err := w.Write(scenario.listResponse); err != nil {
+						t.Fatal(err)
+					}
+					return
+				}
+
+				// handle WATCH response
+				enc := restclientwatch.NewEncoder(streaming.NewEncoder(w, unstructured.UnstructuredJSONScheme), unstructured.UnstructuredJSONScheme)
+				for _, e := range scenario.watchResponse {
+					if err := enc.Encode(&e); err != nil {
+						t.Fatal(err)
+					}
+				}
+			})
+			if err != nil {
+				t.Fatalf("unexpected error when creating test client and server: %v", err)
+			}
+			defer srv.Close()
+
+			actualList, err := cl.Resource(resource).Namespace(scenario.namespace).List(context.TODO(), metav1.ListOptions{})
+			if err != nil {
+				t.Fatalf("unexpected error: %v", err)
+			}
+
+			if !cmp.Equal(scenario.expectedRequestParams, actualRequestParams) {
+				t.Fatalf("unexpected request params: %v", cmp.Diff(scenario.expectedRequestParams, actualRequestParams))
+			}
+			if !cmp.Equal(scenario.expectedList, actualList) {
+				t.Errorf("received expected list, diff: %s", cmp.Diff(scenario.expectedList, actualList))
+			}
+		})
+	}
+}
+
 func TestGet(t *testing.T) {
 	tcs := []struct {
 		resource    string

dynamic/simple.go

@@ -20,6 +20,7 @@ import (
 	"context"
 	"fmt"
 	"net/http"
+	"time"
 
 	"k8s.io/apimachinery/pkg/api/meta"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -30,6 +31,8 @@ import (
 	"k8s.io/apimachinery/pkg/watch"
 	"k8s.io/client-go/rest"
 	"k8s.io/client-go/util/consistencydetector"
+	"k8s.io/client-go/util/watchlist"
+	"k8s.io/klog/v2"
 )
 
 type DynamicClient struct {
@@ -293,13 +296,22 @@ func (c *dynamicResourceClient) Get(ctx context.Context, name string, opts metav
 	return uncastObj.(*unstructured.Unstructured), nil
 }
 
-func (c *dynamicResourceClient) List(ctx context.Context, opts metav1.ListOptions) (result *unstructured.UnstructuredList, err error) {
+func (c *dynamicResourceClient) List(ctx context.Context, opts metav1.ListOptions) (*unstructured.UnstructuredList, error) {
-	defer func() {
+	if watchListOptions, hasWatchListOptionsPrepared, watchListOptionsErr := watchlist.PrepareWatchListOptionsFromListOptions(opts); watchListOptionsErr != nil {
+		klog.Warningf("Failed preparing watchlist options for %v, falling back to the standard LIST semantics, err = %v", c.resource, watchListOptionsErr)
+	} else if hasWatchListOptionsPrepared {
+		result, err := c.watchList(ctx, watchListOptions)
 		if err == nil {
-			consistencydetector.CheckListFromCacheDataConsistencyIfRequested(ctx, fmt.Sprintf("list request for %v", c.resource), c.list, opts, result)
+			consistencydetector.CheckWatchListFromCacheDataConsistencyIfRequested(ctx, fmt.Sprintf("watchlist request for %v", c.resource), c.list, opts, result)
+			return result, nil
 		}
-	}()
+		klog.Warningf("The watchlist request for %v ended with an error, falling back to the standard LIST semantics, err = %v", c.resource, err)
-	return c.list(ctx, opts)
+	}
+	result, err := c.list(ctx, opts)
+	if err == nil {
+		consistencydetector.CheckListFromCacheDataConsistencyIfRequested(ctx, fmt.Sprintf("list request for %v", c.resource), c.list, opts, result)
+	}
+	return result, err
 }
 
 func (c *dynamicResourceClient) list(ctx context.Context, opts metav1.ListOptions) (*unstructured.UnstructuredList, error) {
@@ -329,6 +341,27 @@ func (c *dynamicResourceClient) list(ctx context.Context, opts metav1.ListOption
 	return list, nil
 }
 
+// watchList establishes a watch stream with the server and returns an unstructured list.
+func (c *dynamicResourceClient) watchList(ctx context.Context, opts metav1.ListOptions) (*unstructured.UnstructuredList, error) {
+	if err := validateNamespaceWithOptionalName(c.namespace); err != nil {
+		return nil, err
+	}
+
+	var timeout time.Duration
+	if opts.TimeoutSeconds != nil {
+		timeout = time.Duration(*opts.TimeoutSeconds) * time.Second
+	}
+
+	result := &unstructured.UnstructuredList{}
+	err := c.client.client.Get().AbsPath(c.makeURLSegments("")...).
+		SpecificallyVersionedParams(&opts, dynamicParameterCodec, versionV1).
+		Timeout(timeout).
+		WatchList(ctx).
+		Into(result)
+
+	return result, err
+}
+
 func (c *dynamicResourceClient) Watch(ctx context.Context, opts metav1.ListOptions) (watch.Interface, error) {
 	opts.Watch = true
 	if err := validateNamespaceWithOptionalName(c.namespace); err != nil {