mirror of
https://github.com/kubernetes/client-go.git
synced 2025-06-26 15:12:06 +00:00
client-go/rest: introduce watchlist
Kubernetes-commit: ad3d138cda76fc0267da5131fa3ff7906e2ddf76
This commit is contained in:
Lukasz Szaszkiewicz
Kubernetes Publisher
parent
47f558294c
commit
a1be94abc3
146
rest/request.go
146
rest/request.go
@ -37,12 +37,15 @@ import (
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"golang.org/x/net/http2"
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"k8s.io/apimachinery/pkg/api/errors"
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"k8s.io/apimachinery/pkg/api/meta"
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metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
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"k8s.io/apimachinery/pkg/conversion"
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"k8s.io/apimachinery/pkg/runtime"
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"k8s.io/apimachinery/pkg/runtime/schema"
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"k8s.io/apimachinery/pkg/runtime/serializer/streaming"
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"k8s.io/apimachinery/pkg/util/net"
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"k8s.io/apimachinery/pkg/watch"
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clientfeatures "k8s.io/client-go/features"
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restclientwatch "k8s.io/client-go/rest/watch"
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"k8s.io/client-go/tools/metrics"
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"k8s.io/client-go/util/flowcontrol"
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@ -768,6 +771,142 @@ func (r *Request) Watch(ctx context.Context) (watch.Interface, error) {
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}
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}
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type WatchListResult struct {
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// err holds any errors we might have received
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// during streaming.
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err error
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// items hold the collected data
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items []runtime.Object
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// initialEventsEndBookmarkRV holds the resource version
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// extracted from the bookmark event that marks
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// the end of the stream.
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initialEventsEndBookmarkRV string
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// gv represents the API version
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// it is used to construct the final list response
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// normally this information is filled by the server
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gv schema.GroupVersion
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}
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func (r WatchListResult) Into(obj runtime.Object) error {
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if r.err != nil {
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return r.err
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}
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listPtr, err := meta.GetItemsPtr(obj)
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if err != nil {
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return err
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}
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listVal, err := conversion.EnforcePtr(listPtr)
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if err != nil {
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return err
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}
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if listVal.Kind() != reflect.Slice {
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return fmt.Errorf("need a pointer to slice, got %v", listVal.Kind())
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}
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if len(r.items) == 0 {
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listVal.Set(reflect.MakeSlice(listVal.Type(), 0, 0))
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} else {
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listVal.Set(reflect.MakeSlice(listVal.Type(), len(r.items), len(r.items)))
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for i, o := range r.items {
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if listVal.Type().Elem() != reflect.TypeOf(o).Elem() {
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return fmt.Errorf("received object type = %v at index = %d, doesn't match the list item type = %v", reflect.TypeOf(o).Elem(), i, listVal.Type().Elem())
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}
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listVal.Index(i).Set(reflect.ValueOf(o).Elem())
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}
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}
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listMeta, err := meta.ListAccessor(obj)
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if err != nil {
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return err
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}
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listMeta.SetResourceVersion(r.initialEventsEndBookmarkRV)
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typeMeta, err := meta.TypeAccessor(obj)
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if err != nil {
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return err
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}
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version := r.gv.String()
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typeMeta.SetAPIVersion(version)
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typeMeta.SetKind(reflect.TypeOf(obj).Elem().Name())
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return nil
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}
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// WatchList establishes a stream to get a consistent snapshot of data
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// from the server as described in https://github.com/kubernetes/enhancements/tree/master/keps/sig-api-machinery/3157-watch-list#proposal
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//
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// Note that the watchlist requires properly setting the ListOptions
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// otherwise it just establishes a regular watch with the server.
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// Check the documentation https://kubernetes.io/docs/reference/using-api/api-concepts/#streaming-lists
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// to see what parameters are currently required.
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func (r *Request) WatchList(ctx context.Context) WatchListResult {
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if !clientfeatures.FeatureGates().Enabled(clientfeatures.WatchListClient) {
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return WatchListResult{err: fmt.Errorf("%q feature gate is not enabled", clientfeatures.WatchListClient)}
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}
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// TODO(#115478): consider validating request parameters (i.e sendInitialEvents).
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// Most users use the generated client, which handles the proper setting of parameters.
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// We don't have validation for other methods (e.g., the Watch)
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// thus, for symmetry, we haven't added additional checks for the WatchList method.
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w, err := r.Watch(ctx)
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if err != nil {
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return WatchListResult{err: err}
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}
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return r.handleWatchList(ctx, w)
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}
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// handleWatchList holds the actual logic for easier unit testing.
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// Note that this function will close the passed watch.
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func (r *Request) handleWatchList(ctx context.Context, w watch.Interface) WatchListResult {
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defer w.Stop()
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var lastKey string
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var items []runtime.Object
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for {
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select {
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case <-ctx.Done():
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return WatchListResult{err: ctx.Err()}
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case event, ok := <-w.ResultChan():
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if !ok {
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return WatchListResult{err: fmt.Errorf("unexpected watch close")}
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}
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if event.Type == watch.Error {
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return WatchListResult{err: errors.FromObject(event.Object)}
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}
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meta, err := meta.Accessor(event.Object)
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if err != nil {
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return WatchListResult{err: fmt.Errorf("failed to parse watch event: %#v", event)}
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}
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switch event.Type {
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case watch.Added:
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// the following check ensures that the response is ordered.
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// earlier servers had a bug that caused them to not sort the output.
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// in such cases, return an error which can trigger fallback logic.
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key := objectKeyFromMeta(meta)
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if len(lastKey) > 0 && lastKey > key {
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return WatchListResult{err: fmt.Errorf("cannot add the obj (%#v) with the key = %s, as it violates the ordering guarantees provided by the watchlist feature in beta phase, lastInsertedKey was = %s", event.Object, key, lastKey)}
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}
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items = append(items, event.Object)
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lastKey = key
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case watch.Bookmark:
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if meta.GetAnnotations()[metav1.InitialEventsAnnotationKey] == "true" {
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return WatchListResult{
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items: items,
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initialEventsEndBookmarkRV: meta.GetResourceVersion(),
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gv: r.c.content.GroupVersion,
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}
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}
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default:
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return WatchListResult{err: fmt.Errorf("unexpected watch event %#v, expected to only receive watch.Added and watch.Bookmark events", event)}
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}
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}
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}
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}
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func (r *Request) newStreamWatcher(resp *http.Response) (watch.Interface, error) {
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contentType := resp.Header.Get("Content-Type")
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mediaType, params, err := mime.ParseMediaType(contentType)
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@ -1470,3 +1609,10 @@ func ValidatePathSegmentName(name string, prefix bool) []string {
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}
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return IsValidPathSegmentName(name)
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}
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func objectKeyFromMeta(objMeta metav1.Object) string {
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if len(objMeta.GetNamespace()) > 0 {
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return fmt.Sprintf("%s/%s", objMeta.GetNamespace(), objMeta.GetName())
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}
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return objMeta.GetName()
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}
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356
rest/request_watchlist_test.go
Normal file
356
rest/request_watchlist_test.go
Normal file
@ -0,0 +1,356 @@
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/*
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Copyright 2024 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package rest
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import (
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"context"
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"fmt"
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"regexp"
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"testing"
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"github.com/google/go-cmp/cmp"
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v1 "k8s.io/api/core/v1"
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apiequality "k8s.io/apimachinery/pkg/api/equality"
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apierrors "k8s.io/apimachinery/pkg/api/errors"
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metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
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"k8s.io/apimachinery/pkg/runtime"
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"k8s.io/apimachinery/pkg/runtime/schema"
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"k8s.io/apimachinery/pkg/watch"
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)
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func TestWatchListResult(t *testing.T) {
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scenarios := []struct {
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name string
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target WatchListResult
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result runtime.Object
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expectedResult *v1.PodList
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expectedErr error
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}{
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{
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name: "not a pointer",
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result: fakeObj{},
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expectedErr: fmt.Errorf("rest.fakeObj is not a list: expected pointer, but got rest.fakeObj type"),
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},
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{
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name: "nil input won't panic",
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result: nil,
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expectedErr: fmt.Errorf("<nil> is not a list: expected pointer, but got invalid kind"),
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},
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{
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name: "not a list",
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result: &v1.Pod{},
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expectedErr: fmt.Errorf("*v1.Pod is not a list: no Items field in this object"),
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},
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{
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name: "an err is always returned",
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result: nil,
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target: WatchListResult{err: fmt.Errorf("dummy err")},
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expectedErr: fmt.Errorf("dummy err"),
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},
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{
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name: "empty list",
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result: &v1.PodList{},
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expectedResult: &v1.PodList{
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TypeMeta: metav1.TypeMeta{Kind: "PodList"},
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Items: []v1.Pod{},
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},
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},
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{
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name: "gv is applied",
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result: &v1.PodList{},
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target: WatchListResult{gv: schema.GroupVersion{Group: "g", Version: "v"}},
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expectedResult: &v1.PodList{
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TypeMeta: metav1.TypeMeta{Kind: "PodList", APIVersion: "g/v"},
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Items: []v1.Pod{},
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},
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},
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{
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name: "gv is applied, empty group",
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result: &v1.PodList{},
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target: WatchListResult{gv: schema.GroupVersion{Version: "v"}},
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expectedResult: &v1.PodList{
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TypeMeta: metav1.TypeMeta{Kind: "PodList", APIVersion: "v"},
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Items: []v1.Pod{},
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},
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},
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{
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name: "rv is applied",
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result: &v1.PodList{},
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target: WatchListResult{initialEventsEndBookmarkRV: "100"},
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expectedResult: &v1.PodList{
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TypeMeta: metav1.TypeMeta{Kind: "PodList"},
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ListMeta: metav1.ListMeta{ResourceVersion: "100"},
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Items: []v1.Pod{},
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},
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},
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{
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name: "items are applied",
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result: &v1.PodList{},
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target: WatchListResult{items: []runtime.Object{makePod(1), makePod(2)}},
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expectedResult: &v1.PodList{
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TypeMeta: metav1.TypeMeta{Kind: "PodList"},
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Items: []v1.Pod{*makePod(1), *makePod(2)},
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},
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},
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{
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name: "type mismatch",
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result: &v1.PodList{},
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target: WatchListResult{items: []runtime.Object{makeNamespace("1")}},
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expectedErr: fmt.Errorf("received object type = v1.Namespace at index = 0, doesn't match the list item type = v1.Pod"),
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},
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}
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for _, scenario := range scenarios {
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t.Run(scenario.name, func(t *testing.T) {
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err := scenario.target.Into(scenario.result)
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if scenario.expectedErr != nil && err == nil {
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t.Fatalf("expected an error = %v, got nil", scenario.expectedErr)
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}
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if scenario.expectedErr == nil && err != nil {
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t.Fatalf("didn't expect an error, got = %v", err)
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}
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if err != nil {
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if scenario.expectedErr.Error() != err.Error() {
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t.Fatalf("unexpected err = %v, expected = %v", err, scenario.expectedErr)
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}
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return
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}
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if !apiequality.Semantic.DeepEqual(scenario.expectedResult, scenario.result) {
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t.Errorf("diff: %v", cmp.Diff(scenario.expectedResult, scenario.result))
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}
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})
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}
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}
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func TestWatchListSuccess(t *testing.T) {
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scenarios := []struct {
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name string
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gv schema.GroupVersion
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watchEvents []watch.Event
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expectedResult *v1.PodList
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}{
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{
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name: "happy path",
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// Note that the APIVersion for the core API group is "v1" (not "core/v1").
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// We fake "core/v1" here to test if the Group part is properly
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// recognized and set on the resulting object.
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gv: schema.GroupVersion{Group: "core", Version: "v1"},
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watchEvents: []watch.Event{
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{Type: watch.Added, Object: makePod(1)},
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{Type: watch.Added, Object: makePod(2)},
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{Type: watch.Bookmark, Object: makeBookmarkEvent(5)},
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},
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expectedResult: &v1.PodList{
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TypeMeta: metav1.TypeMeta{
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APIVersion: "core/v1",
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Kind: "PodList",
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},
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ListMeta: metav1.ListMeta{ResourceVersion: "5"},
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Items: []v1.Pod{*makePod(1), *makePod(2)},
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},
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},
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{
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name: "APIVersion with only version provided is properly set",
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gv: schema.GroupVersion{Version: "v1"},
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watchEvents: []watch.Event{
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{Type: watch.Added, Object: makePod(1)},
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{Type: watch.Bookmark, Object: makeBookmarkEvent(5)},
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},
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expectedResult: &v1.PodList{
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TypeMeta: metav1.TypeMeta{
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APIVersion: "v1",
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Kind: "PodList",
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},
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ListMeta: metav1.ListMeta{ResourceVersion: "5"},
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Items: []v1.Pod{*makePod(1)},
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},
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},
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{
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name: "only the bookmark",
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gv: schema.GroupVersion{Version: "v1"},
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watchEvents: []watch.Event{
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{Type: watch.Bookmark, Object: makeBookmarkEvent(5)},
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},
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expectedResult: &v1.PodList{
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TypeMeta: metav1.TypeMeta{
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APIVersion: "v1",
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Kind: "PodList",
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},
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ListMeta: metav1.ListMeta{ResourceVersion: "5"},
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Items: []v1.Pod{},
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},
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},
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}
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for _, scenario := range scenarios {
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t.Run(scenario.name, func(t *testing.T) {
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ctx := context.Background()
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fakeWatcher := watch.NewFake()
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target := &Request{
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c: &RESTClient{
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content: ClientContentConfig{
|
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GroupVersion: scenario.gv,
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},
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},
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}
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go func(watchEvents []watch.Event) {
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for _, watchEvent := range watchEvents {
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fakeWatcher.Action(watchEvent.Type, watchEvent.Object)
|
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}
|
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}(scenario.watchEvents)
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|
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res := target.handleWatchList(ctx, fakeWatcher)
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if res.err != nil {
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t.Fatal(res.err)
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}
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result := &v1.PodList{}
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if err := res.Into(result); err != nil {
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t.Fatal(err)
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}
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if !apiequality.Semantic.DeepEqual(scenario.expectedResult, result) {
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t.Errorf("diff: %v", cmp.Diff(scenario.expectedResult, result))
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}
|
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if !fakeWatcher.IsStopped() {
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t.Fatalf("the watcher wasn't stopped")
|
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}
|
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})
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}
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}
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func TestWatchListFailure(t *testing.T) {
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scenarios := []struct {
|
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name string
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ctx context.Context
|
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watcher *watch.FakeWatcher
|
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watchEvents []watch.Event
|
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|
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expectedError error
|
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}{
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{
|
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name: "request stop",
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ctx: func() context.Context {
|
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ctx, ctxCancel := context.WithCancel(context.TODO())
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ctxCancel()
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return ctx
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}(),
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watcher: watch.NewFake(),
|
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expectedError: fmt.Errorf("context canceled"),
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},
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{
|
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name: "stop watcher",
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ctx: context.TODO(),
|
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watcher: func() *watch.FakeWatcher {
|
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w := watch.NewFake()
|
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w.Stop()
|
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return w
|
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}(),
|
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expectedError: fmt.Errorf("unexpected watch close"),
|
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},
|
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{
|
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name: "stop on watch.Error",
|
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ctx: context.TODO(),
|
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watcher: watch.NewFake(),
|
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watchEvents: []watch.Event{{Type: watch.Error, Object: &apierrors.NewInternalError(fmt.Errorf("dummy errror")).ErrStatus}},
|
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expectedError: fmt.Errorf("Internal error occurred: dummy errror"),
|
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},
|
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{
|
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name: "incorrect watch type (Deleted)",
|
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ctx: context.TODO(),
|
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watcher: watch.NewFake(),
|
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watchEvents: []watch.Event{{Type: watch.Deleted, Object: makePod(1)}},
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expectedError: fmt.Errorf("unexpected watch event .*, expected to only receive watch.Added and watch.Bookmark events"),
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},
|
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{
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name: "incorrect watch type (Modified)",
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ctx: context.TODO(),
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watcher: watch.NewFake(),
|
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watchEvents: []watch.Event{{Type: watch.Modified, Object: makePod(1)}},
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expectedError: fmt.Errorf("unexpected watch event .*, expected to only receive watch.Added and watch.Bookmark events"),
|
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},
|
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{
|
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name: "unordered input returns an error",
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ctx: context.TODO(),
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||||
watcher: watch.NewFake(),
|
||||
watchEvents: []watch.Event{{Type: watch.Added, Object: makePod(3)}, {Type: watch.Added, Object: makePod(1)}},
|
||||
expectedError: fmt.Errorf("cannot add the obj .* with the key = ns/pod-1, as it violates the ordering guarantees provided by the watchlist feature in beta phase, lastInsertedKey was = ns/pod-3"),
|
||||
},
|
||||
}
|
||||
|
||||
for _, scenario := range scenarios {
|
||||
t.Run(scenario.name, func(t *testing.T) {
|
||||
target := &Request{}
|
||||
go func(w *watch.FakeWatcher, watchEvents []watch.Event) {
|
||||
for _, event := range watchEvents {
|
||||
w.Action(event.Type, event.Object)
|
||||
}
|
||||
}(scenario.watcher, scenario.watchEvents)
|
||||
|
||||
res := target.handleWatchList(scenario.ctx, scenario.watcher)
|
||||
resErr := res.Into(nil)
|
||||
if resErr == nil {
|
||||
t.Fatal("expected to get an error, got nil")
|
||||
}
|
||||
matched, err := regexp.MatchString(scenario.expectedError.Error(), resErr.Error())
|
||||
if err != nil {
|
||||
t.Fatal(err)
|
||||
}
|
||||
if !matched {
|
||||
t.Fatalf("unexpected err = %v, expected = %v", resErr, scenario.expectedError)
|
||||
}
|
||||
if !scenario.watcher.IsStopped() {
|
||||
t.Fatalf("the watcher wasn't stopped")
|
||||
}
|
||||
})
|
||||
}
|
||||
}
|
||||
|
||||
func makePod(rv uint64) *v1.Pod {
|
||||
return &v1.Pod{
|
||||
ObjectMeta: metav1.ObjectMeta{
|
||||
Name: fmt.Sprintf("pod-%d", rv),
|
||||
Namespace: "ns",
|
||||
ResourceVersion: fmt.Sprintf("%d", rv),
|
||||
Annotations: map[string]string{},
|
||||
},
|
||||
}
|
||||
}
|
||||
|
||||
func makeNamespace(name string) *v1.Namespace {
|
||||
return &v1.Namespace{ObjectMeta: metav1.ObjectMeta{Name: name}}
|
||||
}
|
||||
|
||||
func makeBookmarkEvent(rv uint64) *v1.Pod {
|
||||
return &v1.Pod{
|
||||
ObjectMeta: metav1.ObjectMeta{
|
||||
ResourceVersion: fmt.Sprintf("%d", rv),
|
||||
Annotations: map[string]string{metav1.InitialEventsAnnotationKey: "true"},
|
||||
},
|
||||
}
|
||||
}
|
||||
|
||||
type fakeObj struct {
|
||||
}
|
||||
|
||||
func (f fakeObj) GetObjectKind() schema.ObjectKind {
|
||||
return schema.EmptyObjectKind
|
||||
}
|
||||
|
||||
func (f fakeObj) DeepCopyObject() runtime.Object {
|
||||
return fakeObj{}
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user