Merge pull request #62734 from liggitt/log-malformed-webhook

Automatic merge from submit-queue (batch tested with PRs 62378, 62734). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Log webhook request error

Fixed https://github.com/kubernetes/kubernetes/issues/26606

```release-note
NONE
```

staging/src/k8s.io/apiserver/plugin/pkg/authenticator/token/webhook/BUILD

@@ -26,6 +26,7 @@ go_library(
     srcs = ["webhook.go"],
     importpath = "k8s.io/apiserver/plugin/pkg/authenticator/token/webhook",
     deps = [
+        "//vendor/github.com/golang/glog:go_default_library",
         "//vendor/k8s.io/api/authentication/v1beta1:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/apimachinery/registered:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/runtime/schema:go_default_library",

staging/src/k8s.io/apiserver/plugin/pkg/authenticator/token/webhook/webhook.go

@@ -21,6 +21,8 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/golang/glog"
+
 	authentication "k8s.io/api/authentication/v1beta1"
 	"k8s.io/apimachinery/pkg/apimachinery/registered"
 	"k8s.io/apimachinery/pkg/runtime/schema"
@@ -84,6 +86,8 @@ func (w *WebhookTokenAuthenticator) AuthenticateToken(token string) (user.Info,
 			return err
 		})
 		if err != nil {
+			// An error here indicates bad configuration or an outage. Log for debugging.
+			glog.Errorf("Failed to make webhook authenticator request: %v", err)
 			return nil, false, err
 		}
 		r.Status = result.Status