Merge pull request #62901 from hzxuzhonghu/eventratelimit-aggregate-errors

Automatic merge from submit-queue (batch tested with PRs 62901, 66562, 66938, 66927, 66926). 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>.

Eventratelimit aggregates all reject errors

Previously, Eventratelimit validates event by each limiter but only returns the last reject error. Which is not accurate, so here I aggregate each error.

**Release note**:

```release-note
NONE
```

plugin/pkg/admission/eventratelimit/BUILD

@@ -46,6 +46,7 @@ go_library(
         "//staging/src/k8s.io/apimachinery/pkg/api/errors:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/runtime:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/runtime/serializer:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/util/errors:go_default_library",
         "//staging/src/k8s.io/apiserver/pkg/admission:go_default_library",
         "//staging/src/k8s.io/client-go/util/flowcontrol:go_default_library",
         "//vendor/github.com/hashicorp/golang-lru:go_default_library",

plugin/pkg/admission/eventratelimit/admission.go

@@ -19,6 +19,8 @@ package eventratelimit
 import (
 	"io"
 
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	utilerrors "k8s.io/apimachinery/pkg/util/errors"
 	"k8s.io/apiserver/pkg/admission"
 	"k8s.io/client-go/util/flowcontrol"
 	api "k8s.io/kubernetes/pkg/apis/core"
@@ -85,13 +87,17 @@ func (a *Plugin) Validate(attr admission.Attributes) (err error) {
 		return nil
 	}
 
-	var rejectionError error
+	var errors []error
 	// give each limit enforcer a chance to reject the event
 	for _, enforcer := range a.limitEnforcers {
 		if err := enforcer.accept(attr); err != nil {
-			rejectionError = err
+			errors = append(errors, err)
 		}
 	}
 
-	return rejectionError
+	if aggregatedErr := utilerrors.NewAggregate(errors); aggregatedErr != nil {
+		return apierrors.NewTooManyRequestsError(aggregatedErr.Error())
+	}
+
+	return nil
 }

plugin/pkg/admission/eventratelimit/limitenforcer.go

@@ -22,7 +22,6 @@ import (
 
 	"github.com/hashicorp/golang-lru"
 
-	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apiserver/pkg/admission"
 	"k8s.io/client-go/util/flowcontrol"
 	api "k8s.io/kubernetes/pkg/apis/core"
@@ -99,7 +98,7 @@ func (enforcer *limitEnforcer) accept(attr admission.Attributes) error {
 	allow := rateLimiter.TryAccept()
 
 	if !allow {
-		return apierrors.NewTooManyRequestsError(fmt.Sprintf("limit reached on type %v for key %v", enforcer.limitType, key))
+		return fmt.Errorf("limit reached on type %v for key %v", enforcer.limitType, key)
 	}
 
 	return nil