Remove warning log for merging meta and scale type

staging/src/k8s.io/apiextensions-apiserver/pkg/controller/openapi/builder/merge.go

@@ -17,12 +17,17 @@ limitations under the License.
 package builder
 
 import (
-	"k8s.io/klog/v2"
+	"fmt"
+	"strings"
+
 	"k8s.io/kube-openapi/pkg/aggregator"
 	"k8s.io/kube-openapi/pkg/spec3"
 	"k8s.io/kube-openapi/pkg/validation/spec"
 )
 
+const metadataGV = "io.k8s.apimachinery.pkg.apis.meta.v1"
+const autoscalingGV = "io.k8s.api.autoscaling.v1"
+
 // MergeSpecs aggregates all OpenAPI specs, reusing the metadata of the first, static spec as the basis.
 // The static spec has the highest priority, and its paths and definitions won't get overlapped by
 // user-defined CRDs. None of the input is mutated, but input and output share data structures.
@@ -83,28 +88,29 @@ func mergeSpec(dest, source *spec.Swagger) {
 }
 
 // MergeSpecsV3 merges OpenAPI v3 specs for CRDs
-// For V3, the static spec is never merged with the individual CRD specs so no conflict resolution is necessary
+// Conflicts belonging to the meta.v1 or autoscaling.v1 group versions are skipped as all CRDs reference those types
+// Other conflicts will result in an error
 func MergeSpecsV3(crdSpecs ...*spec3.OpenAPI) (*spec3.OpenAPI, error) {
-	// create shallow copy of staticSpec, but replace paths and definitions because we modify them.
 	crdSpec := &spec3.OpenAPI{}
 	if len(crdSpecs) > 0 {
 		crdSpec.Version = crdSpecs[0].Version
 		crdSpec.Info = crdSpecs[0].Info
 	}
 	for _, s := range crdSpecs {
-		// merge specs without checking conflicts, since the naming controller prevents
+		err := mergeSpecV3(crdSpec, s)
-		// conflicts between user-defined CRDs
+		if err != nil {
-		mergeSpecV3(crdSpec, s)
+			return nil, err
+		}
 	}
-
 	return crdSpec, nil
 }
 
 // mergeSpecV3 copies paths and definitions from source to dest, mutating dest, but not source.
-// We assume that conflicts do not matter.
+// Conflicts belonging to the meta.v1 or autoscaling.v1 group versions are skipped as all CRDs reference those types
-func mergeSpecV3(dest, source *spec3.OpenAPI) {
+// Other conflicts will result in an error
+func mergeSpecV3(dest, source *spec3.OpenAPI) error {
 	if source == nil || source.Paths == nil {
-		return
+		return nil
 	}
 	if dest.Paths == nil {
 		dest.Paths = &spec3.Paths{}
@@ -118,7 +124,10 @@ func mergeSpecV3(dest, source *spec3.OpenAPI) {
 			dest.Components.Schemas = map[string]*spec.Schema{}
 		}
 		if _, exists := dest.Components.Schemas[k]; exists {
-			klog.Warningf("Should not happen: OpenAPI V3 merge schema conflict on %s", k)
+			if strings.HasPrefix(k, metadataGV) || strings.HasPrefix(k, autoscalingGV) {
+				continue
+			}
+			return fmt.Errorf("OpenAPI V3 merge schema conflict on %s", k)
 		}
 		dest.Components.Schemas[k] = v
 	}
@@ -128,4 +137,5 @@ func mergeSpecV3(dest, source *spec3.OpenAPI) {
 		}
 		dest.Paths.Paths[k] = v
 	}
+	return nil
 }

staging/src/k8s.io/apiextensions-apiserver/pkg/controller/openapi/builder/merge_test.go

@@ -0,0 +1,170 @@
+/*
+Copyright 2022 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 builder
+
+import (
+	"reflect"
+	"testing"
+
+	"k8s.io/kube-openapi/pkg/spec3"
+	"k8s.io/kube-openapi/pkg/validation/spec"
+)
+
+func TestMergeSpecV3(t *testing.T) {
+	tests := []struct {
+		name     string
+		specs    []*spec3.OpenAPI
+		expected *spec3.OpenAPI
+	}{
+		{
+			name: "oneCRD",
+			specs: []*spec3.OpenAPI{{
+				Paths: &spec3.Paths{
+					Paths: map[string]*spec3.Path{
+						"/apis/stable.example.com/v1/crd1": {},
+					},
+				},
+				Components: &spec3.Components{
+					Schemas: map[string]*spec.Schema{
+						"io.k8s.apimachinery.pkg.apis.meta.v1.ObjectMeta": {},
+					},
+				},
+			},
+			},
+			expected: &spec3.OpenAPI{
+				Paths: &spec3.Paths{
+					Paths: map[string]*spec3.Path{
+						"/apis/stable.example.com/v1/crd1": {},
+					},
+				},
+				Components: &spec3.Components{
+					Schemas: map[string]*spec.Schema{
+						"io.k8s.apimachinery.pkg.apis.meta.v1.ObjectMeta": {},
+					},
+				},
+			},
+		},
+		{
+			name: "two CRDs same gv",
+			specs: []*spec3.OpenAPI{{
+				Paths: &spec3.Paths{
+					Paths: map[string]*spec3.Path{
+						"/apis/stable.example.com/v1/crd1": {},
+					},
+				},
+				Components: &spec3.Components{
+					Schemas: map[string]*spec.Schema{
+						"com.example.stable.v1.CRD1": {},
+
+						"io.k8s.apimachinery.pkg.apis.meta.v1.ObjectMeta": {},
+					},
+				},
+			},
+				{
+					Paths: &spec3.Paths{
+						Paths: map[string]*spec3.Path{
+							"/apis/stable.example.com/v1/crd2": {},
+						},
+					},
+					Components: &spec3.Components{
+						Schemas: map[string]*spec.Schema{
+							"com.example.stable.v1.CRD2":                      {},
+							"io.k8s.apimachinery.pkg.apis.meta.v1.ObjectMeta": {},
+						},
+					},
+				},
+			},
+			expected: &spec3.OpenAPI{
+				Paths: &spec3.Paths{
+					Paths: map[string]*spec3.Path{
+						"/apis/stable.example.com/v1/crd1": {},
+						"/apis/stable.example.com/v1/crd2": {},
+					},
+				},
+				Components: &spec3.Components{
+					Schemas: map[string]*spec.Schema{
+						"io.k8s.apimachinery.pkg.apis.meta.v1.ObjectMeta": {},
+						"com.example.stable.v1.CRD1":                      {},
+						"com.example.stable.v1.CRD2":                      {},
+					},
+				},
+			},
+		},
+		{
+			name: "two CRDs with scale",
+			specs: []*spec3.OpenAPI{{
+				Paths: &spec3.Paths{
+					Paths: map[string]*spec3.Path{
+						"/apis/stable.example.com/v1/crd1": {},
+					},
+				},
+				Components: &spec3.Components{
+					Schemas: map[string]*spec.Schema{
+						"com.example.stable.v1.CRD1": {},
+
+						"io.k8s.apimachinery.pkg.apis.meta.v1.ObjectMeta": {},
+						"io.k8s.api.autoscaling.v1.Scale":                 {},
+					},
+				},
+			},
+				{
+					Paths: &spec3.Paths{
+						Paths: map[string]*spec3.Path{
+							"/apis/stable.example.com/v1/crd2": {},
+						},
+					},
+					Components: &spec3.Components{
+						Schemas: map[string]*spec.Schema{
+							"com.example.stable.v1.CRD2":                      {},
+							"io.k8s.apimachinery.pkg.apis.meta.v1.ObjectMeta": {},
+							"io.k8s.api.autoscaling.v1.Scale":                 {},
+						},
+					},
+				},
+			},
+			expected: &spec3.OpenAPI{
+				Paths: &spec3.Paths{
+					Paths: map[string]*spec3.Path{
+						"/apis/stable.example.com/v1/crd1": {},
+						"/apis/stable.example.com/v1/crd2": {},
+					},
+				},
+				Components: &spec3.Components{
+					Schemas: map[string]*spec.Schema{
+						"io.k8s.apimachinery.pkg.apis.meta.v1.ObjectMeta": {},
+						"com.example.stable.v1.CRD1":                      {},
+						"com.example.stable.v1.CRD2":                      {},
+						"io.k8s.api.autoscaling.v1.Scale":                 {},
+					},
+				},
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			merged, err := MergeSpecsV3(tt.specs...)
+			if err != nil {
+				t.Error(err)
+			}
+			if !reflect.DeepEqual(merged, tt.expected) {
+				t.Error("Merged spec is different from expected spec")
+			}
+
+		})
+	}
+}