From 603dd254ac91b3581f9b431ff91a95d929a97e04 Mon Sep 17 00:00:00 2001
From: Tomas Nozicka <tnozicka@gmail.com>
Date: Mon, 18 Feb 2019 18:20:23 +0100
Subject: [PATCH] Upgrade ListWatchUntil

---
 pkg/client/tests/listwatch_test.go            | 19 +++++++++---
 .../src/k8s.io/client-go/tools/watch/until.go | 29 ++++++-------------
 2 files changed, 24 insertions(+), 24 deletions(-)

diff --git a/pkg/client/tests/listwatch_test.go b/pkg/client/tests/listwatch_test.go
index 35a8a256e44..1adaf67adbf 100644
--- a/pkg/client/tests/listwatch_test.go
+++ b/pkg/client/tests/listwatch_test.go
@@ -17,6 +17,7 @@ limitations under the License.
 package tests
 
 import (
+	"context"
 	"net/http/httptest"
 	"net/url"
 	"testing"
@@ -194,11 +195,20 @@ func (w lw) Watch(options metav1.ListOptions) (watch.Interface, error) {
 func TestListWatchUntil(t *testing.T) {
 	fw := watch.NewFake()
 	go func() {
-		var obj *v1.Pod
+		obj := &v1.Pod{
+			ObjectMeta: metav1.ObjectMeta{
+				ResourceVersion: "2",
+			},
+		}
 		fw.Modify(obj)
 	}()
 	listwatch := lw{
-		list:  &v1.PodList{Items: []v1.Pod{{}}},
+		list: &v1.PodList{
+			ListMeta: metav1.ListMeta{
+				ResourceVersion: "1",
+			},
+			Items: []v1.Pod{{}},
+		},
 		watch: fw,
 	}
 
@@ -213,8 +223,9 @@ func TestListWatchUntil(t *testing.T) {
 		},
 	}
 
-	timeout := 10 * time.Second
-	lastEvent, err := watchtools.ListWatchUntil(timeout, listwatch, conditions...)
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	lastEvent, err := watchtools.ListWatchUntil(ctx, listwatch, conditions...)
 	if err != nil {
 		t.Fatalf("expected nil error, got %#v", err)
 	}
diff --git a/staging/src/k8s.io/client-go/tools/watch/until.go b/staging/src/k8s.io/client-go/tools/watch/until.go
index 0a341a444fc..e12d82aca48 100644
--- a/staging/src/k8s.io/client-go/tools/watch/until.go
+++ b/staging/src/k8s.io/client-go/tools/watch/until.go
@@ -168,13 +168,14 @@ func ContextWithOptionalTimeout(parent context.Context, timeout time.Duration) (
 	return context.WithTimeout(parent, timeout)
 }
 
-// ListWatchUntil checks the provided conditions against the items returned by the list watcher, returning wait.ErrWaitTimeout
-// if timeout is exceeded without all conditions returning true, or an error if an error occurs.
-// TODO: check for watch expired error and retry watch from latest point?  Same issue exists for Until.
-// TODO: remove when no longer used
-//
-// Deprecated: Use UntilWithSync instead.
-func ListWatchUntil(timeout time.Duration, lw cache.ListerWatcher, conditions ...ConditionFunc) (*watch.Event, error) {
+// 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
 	}
@@ -231,17 +232,5 @@ func ListWatchUntil(timeout time.Duration, lw cache.ListerWatcher, conditions ..
 	}
 	currResourceVersion := metaObj.GetResourceVersion()
 
-	watchInterface, err := lw.Watch(metav1.ListOptions{ResourceVersion: currResourceVersion})
-	if err != nil {
-		return nil, err
-	}
-
-	ctx, cancel := ContextWithOptionalTimeout(context.Background(), timeout)
-	defer cancel()
-	evt, err := UntilWithoutRetry(ctx, watchInterface, remainingConditions...)
-	if err == ErrWatchClosed {
-		// present a consistent error interface to callers
-		err = wait.ErrWaitTimeout
-	}
-	return evt, err
+	return Until(ctx, currResourceVersion, lw, remainingConditions...)
 }