vendor update for E2E framework

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

vendor/k8s.io/client-go/tools/watch/until.go

@@ -0,0 +1,236 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package watch
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"time"
+
+	"k8s.io/apimachinery/pkg/api/meta"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/apimachinery/pkg/watch"
+	"k8s.io/client-go/tools/cache"
+	"k8s.io/klog"
+)
+
+// PreconditionFunc returns true if the condition has been reached, false if it has not been reached yet,
+// or an error if the condition failed or detected an error state.
+type PreconditionFunc func(store cache.Store) (bool, error)
+
+// ConditionFunc returns true if the condition has been reached, false if it has not been reached yet,
+// or an error if the condition cannot be checked and should terminate. In general, it is better to define
+// level driven conditions over edge driven conditions (pod has ready=true, vs pod modified and ready changed
+// from false to true).
+type ConditionFunc func(event watch.Event) (bool, error)
+
+// ErrWatchClosed is returned when the watch channel is closed before timeout in UntilWithoutRetry.
+var ErrWatchClosed = errors.New("watch closed before UntilWithoutRetry timeout")
+
+// UntilWithoutRetry reads items from the watch until each provided condition succeeds, and then returns the last watch
+// encountered. The first condition that returns an error terminates the watch (and the event is also returned).
+// If no event has been received, the returned event will be nil.
+// Conditions are satisfied sequentially so as to provide a useful primitive for higher level composition.
+// Waits until context deadline or until context is canceled.
+//
+// Warning: Unless you have a very specific use case (probably a special Watcher) don't use this function!!!
+// Warning: This will fail e.g. on API timeouts and/or 'too old resource version' error.
+// Warning: You are most probably looking for a function *Until* or *UntilWithSync* below,
+// Warning: solving such issues.
+// TODO: Consider making this function private to prevent misuse when the other occurrences in our codebase are gone.
+func UntilWithoutRetry(ctx context.Context, watcher watch.Interface, conditions ...ConditionFunc) (*watch.Event, error) {
+	ch := watcher.ResultChan()
+	defer watcher.Stop()
+	var lastEvent *watch.Event
+	for _, condition := range conditions {
+		// check the next condition against the previous event and short circuit waiting for the next watch
+		if lastEvent != nil {
+			done, err := condition(*lastEvent)
+			if err != nil {
+				return lastEvent, err
+			}
+			if done {
+				continue
+			}
+		}
+	ConditionSucceeded:
+		for {
+			select {
+			case event, ok := <-ch:
+				if !ok {
+					return lastEvent, ErrWatchClosed
+				}
+				lastEvent = &event
+
+				done, err := condition(event)
+				if err != nil {
+					return lastEvent, err
+				}
+				if done {
+					break ConditionSucceeded
+				}
+
+			case <-ctx.Done():
+				return lastEvent, wait.ErrWaitTimeout
+			}
+		}
+	}
+	return lastEvent, nil
+}
+
+// Until wraps the watcherClient's watch function with RetryWatcher making sure that watcher gets restarted in case of errors.
+// The initialResourceVersion will be given to watch method when first called. It shall not be "" or "0"
+// given the underlying WATCH call issues (#74022). If you want the initial list ("", "0") done for you use ListWatchUntil instead.
+// Remaining behaviour is identical to function UntilWithoutRetry. (See above.)
+// Until can deal with API timeouts and lost connections.
+// It guarantees you to see all events and in the order they happened.
+// Due to this guarantee there is no way it can deal with 'Resource version too old error'. It will fail in this case.
+// (See `UntilWithSync` if you'd prefer to recover from all the errors including RV too old by re-listing
+//  those items. In normal code you should care about being level driven so you'd not care about not seeing all the edges.)
+// The most frequent usage for Until would be a test where you want to verify exact order of events ("edges").
+func Until(ctx context.Context, initialResourceVersion string, watcherClient cache.Watcher, conditions ...ConditionFunc) (*watch.Event, error) {
+	w, err := NewRetryWatcher(initialResourceVersion, watcherClient)
+	if err != nil {
+		return nil, err
+	}
+
+	return UntilWithoutRetry(ctx, w, conditions...)
+}
+
+// UntilWithSync creates an informer from lw, optionally checks precondition when the store is synced,
+// and watches the output until each provided condition succeeds, in a way that is identical
+// to function UntilWithoutRetry. (See above.)
+// UntilWithSync can deal with all errors like API timeout, lost connections and 'Resource version too old'.
+// It is the only function that can recover from 'Resource version too old', Until and UntilWithoutRetry will
+// just fail in that case. On the other hand it can't provide you with guarantees as strong as using simple
+// Watch method with Until. It can skip some intermediate events in case of watch function failing but it will
+// re-list to recover and you always get an event, if there has been a change, after recovery.
+// Also with the current implementation based on DeltaFIFO, order of the events you receive is guaranteed only for
+// particular object, not between more of them even it's the same resource.
+// The most frequent usage would be a command that needs to watch the "state of the world" and should't fail, like:
+// waiting for object reaching a state, "small" controllers, ...
+func UntilWithSync(ctx context.Context, lw cache.ListerWatcher, objType runtime.Object, precondition PreconditionFunc, conditions ...ConditionFunc) (*watch.Event, error) {
+	indexer, informer, watcher, done := NewIndexerInformerWatcher(lw, objType)
+	// We need to wait for the internal informers to fully stop so it's easier to reason about
+	// and it works with non-thread safe clients.
+	defer func() { <-done }()
+	// Proxy watcher can be stopped multiple times so it's fine to use defer here to cover alternative branches and
+	// let UntilWithoutRetry to stop it
+	defer watcher.Stop()
+
+	if precondition != nil {
+		if !cache.WaitForCacheSync(ctx.Done(), informer.HasSynced) {
+			return nil, fmt.Errorf("UntilWithSync: unable to sync caches: %v", ctx.Err())
+		}
+
+		done, err := precondition(indexer)
+		if err != nil {
+			return nil, err
+		}
+
+		if done {
+			return nil, nil
+		}
+	}
+
+	return UntilWithoutRetry(ctx, watcher, conditions...)
+}
+
+// ContextWithOptionalTimeout wraps context.WithTimeout and handles infinite timeouts expressed as 0 duration.
+func ContextWithOptionalTimeout(parent context.Context, timeout time.Duration) (context.Context, context.CancelFunc) {
+	if timeout < 0 {
+		// This should be handled in validation
+		klog.Errorf("Timeout for context shall not be negative!")
+		timeout = 0
+	}
+
+	if timeout == 0 {
+		return context.WithCancel(parent)
+	}
+
+	return context.WithTimeout(parent, timeout)
+}
+
+// ListWatchUntil first lists objects, converts them into synthetic ADDED events
+// and checks conditions for those synthetic events. If the conditions have not been reached so far
+// it continues by calling Until which establishes a watch from resourceVersion of the list call
+// to evaluate those conditions based on new events.
+// ListWatchUntil provides the same guarantees as Until and replaces the old WATCH from RV "" (or "0")
+// which was mixing list and watch calls internally and having severe design issues. (see #74022)
+// There is no resourceVersion order guarantee for the initial list and those synthetic events.
+func ListWatchUntil(ctx context.Context, lw cache.ListerWatcher, conditions ...ConditionFunc) (*watch.Event, error) {
+	if len(conditions) == 0 {
+		return nil, nil
+	}
+
+	list, err := lw.List(metav1.ListOptions{})
+	if err != nil {
+		return nil, err
+	}
+	initialItems, err := meta.ExtractList(list)
+	if err != nil {
+		return nil, err
+	}
+
+	// use the initial items as simulated "adds"
+	var lastEvent *watch.Event
+	currIndex := 0
+	passedConditions := 0
+	for _, condition := range conditions {
+		// check the next condition against the previous event and short circuit waiting for the next watch
+		if lastEvent != nil {
+			done, err := condition(*lastEvent)
+			if err != nil {
+				return lastEvent, err
+			}
+			if done {
+				passedConditions = passedConditions + 1
+				continue
+			}
+		}
+
+	ConditionSucceeded:
+		for currIndex < len(initialItems) {
+			lastEvent = &watch.Event{Type: watch.Added, Object: initialItems[currIndex]}
+			currIndex++
+
+			done, err := condition(*lastEvent)
+			if err != nil {
+				return lastEvent, err
+			}
+			if done {
+				passedConditions = passedConditions + 1
+				break ConditionSucceeded
+			}
+		}
+	}
+	if passedConditions == len(conditions) {
+		return lastEvent, nil
+	}
+	remainingConditions := conditions[passedConditions:]
+
+	metaObj, err := meta.ListAccessor(list)
+	if err != nil {
+		return nil, err
+	}
+	currResourceVersion := metaObj.GetResourceVersion()
+
+	return Until(ctx, currResourceVersion, lw, remainingConditions...)
+}