Upgrade ListWatchUntil

pull/564/head
Tomas Nozicka 2019-02-18 18:20:23 +01:00
parent 09af8485f2
commit 603dd254ac
2 changed files with 24 additions and 24 deletions

View File

@ -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)
}

View File

@ -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...)
}