🐛 Return NoResourceMatchError when appropriate for backwards compatibility.

pkg/client/apiutil/errors.go

@@ -0,0 +1,54 @@
+/*
+Copyright 2023 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 apiutil
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apimachinery/pkg/api/meta"
+
+	"k8s.io/apimachinery/pkg/runtime/schema"
+)
+
+// ErrResourceDiscoveryFailed is returned if the RESTMapper cannot discover supported resources for some GroupVersions.
+// It wraps the errors encountered, except "NotFound" errors are replaced with meta.NoResourceMatchError, for
+// backwards compatibility with code that uses meta.IsNoMatchError() to check for unsupported APIs.
+type ErrResourceDiscoveryFailed map[schema.GroupVersion]error
+
+// Error implements the error interface.
+func (e *ErrResourceDiscoveryFailed) Error() string {
+	subErrors := []string{}
+	for k, v := range *e {
+		subErrors = append(subErrors, fmt.Sprintf("%s: %v", k, v))
+	}
+	sort.Strings(subErrors)
+	return fmt.Sprintf("unable to retrieve the complete list of server APIs: %s", strings.Join(subErrors, ", "))
+}
+
+func (e *ErrResourceDiscoveryFailed) Unwrap() []error {
+	subErrors := []error{}
+	for gv, err := range *e {
+		if apierrors.IsNotFound(err) {
+			err = &meta.NoResourceMatchError{PartialResource: gv.WithResource("")}
+		}
+		subErrors = append(subErrors, err)
+	}
+	return subErrors
+}

pkg/client/apiutil/restmapper.go

@@ -286,7 +286,8 @@ func (m *mapper) fetchGroupVersionResources(groupName string, versions ...string
 	}
 
 	if len(failedGroups) > 0 {
-		return nil, &discovery.ErrGroupDiscoveryFailed{Groups: failedGroups}
+		err := ErrResourceDiscoveryFailed(failedGroups)
+		return nil, &err
 	}
 
 	return groupVersionResources, nil

pkg/client/apiutil/restmapper_test.go

@@ -21,6 +21,8 @@ import (
 	"net/http"
 	"testing"
 
+	"k8s.io/apimachinery/pkg/api/meta"
+
 	_ "github.com/onsi/ginkgo/v2"
 	gmg "github.com/onsi/gomega"
 
@@ -303,26 +305,32 @@ func TestLazyRestMapperProvider(t *testing.T) {
 
 		_, err = lazyRestMapper.RESTMapping(schema.GroupKind{Group: "INVALID1"}, "v1")
 		g.Expect(err).To(gmg.HaveOccurred())
+		g.Expect(meta.IsNoMatchError(err)).To(gmg.BeTrue())
 		g.Expect(crt.GetRequestCount()).To(gmg.Equal(1))
 
 		_, err = lazyRestMapper.RESTMappings(schema.GroupKind{Group: "INVALID2"}, "v1")
 		g.Expect(err).To(gmg.HaveOccurred())
+		g.Expect(meta.IsNoMatchError(err)).To(gmg.BeTrue())
 		g.Expect(crt.GetRequestCount()).To(gmg.Equal(2))
 
 		_, err = lazyRestMapper.KindFor(schema.GroupVersionResource{Group: "INVALID3", Version: "v1"})
 		g.Expect(err).To(gmg.HaveOccurred())
+		g.Expect(meta.IsNoMatchError(err)).To(gmg.BeTrue())
 		g.Expect(crt.GetRequestCount()).To(gmg.Equal(3))
 
 		_, err = lazyRestMapper.KindsFor(schema.GroupVersionResource{Group: "INVALID4", Version: "v1"})
 		g.Expect(err).To(gmg.HaveOccurred())
+		g.Expect(meta.IsNoMatchError(err)).To(gmg.BeTrue())
 		g.Expect(crt.GetRequestCount()).To(gmg.Equal(4))
 
 		_, err = lazyRestMapper.ResourceFor(schema.GroupVersionResource{Group: "INVALID5", Version: "v1"})
 		g.Expect(err).To(gmg.HaveOccurred())
+		g.Expect(meta.IsNoMatchError(err)).To(gmg.BeTrue())
 		g.Expect(crt.GetRequestCount()).To(gmg.Equal(5))
 
 		_, err = lazyRestMapper.ResourcesFor(schema.GroupVersionResource{Group: "INVALID6", Version: "v1"})
 		g.Expect(err).To(gmg.HaveOccurred())
+		g.Expect(meta.IsNoMatchError(err)).To(gmg.BeTrue())
 		g.Expect(crt.GetRequestCount()).To(gmg.Equal(6))
 	})
 
@@ -342,26 +350,32 @@ func TestLazyRestMapperProvider(t *testing.T) {
 
 		_, err = lazyRestMapper.RESTMapping(schema.GroupKind{Group: "apps", Kind: "INVALID"}, "v1")
 		g.Expect(err).To(gmg.HaveOccurred())
+		g.Expect(meta.IsNoMatchError(err)).To(gmg.BeTrue())
 		g.Expect(crt.GetRequestCount()).To(gmg.Equal(1))
 
 		_, err = lazyRestMapper.RESTMappings(schema.GroupKind{Group: "", Kind: "INVALID"}, "v1")
 		g.Expect(err).To(gmg.HaveOccurred())
+		g.Expect(meta.IsNoMatchError(err)).To(gmg.BeTrue())
 		g.Expect(crt.GetRequestCount()).To(gmg.Equal(2))
 
 		_, err = lazyRestMapper.KindFor(schema.GroupVersionResource{Group: "networking.k8s.io", Version: "v1", Resource: "INVALID"})
 		g.Expect(err).To(gmg.HaveOccurred())
+		g.Expect(meta.IsNoMatchError(err)).To(gmg.BeTrue())
 		g.Expect(crt.GetRequestCount()).To(gmg.Equal(3))
 
 		_, err = lazyRestMapper.KindsFor(schema.GroupVersionResource{Group: "authentication.k8s.io", Version: "v1", Resource: "INVALID"})
 		g.Expect(err).To(gmg.HaveOccurred())
+		g.Expect(meta.IsNoMatchError(err)).To(gmg.BeTrue())
 		g.Expect(crt.GetRequestCount()).To(gmg.Equal(4))
 
 		_, err = lazyRestMapper.ResourceFor(schema.GroupVersionResource{Group: "scheduling.k8s.io", Version: "v1", Resource: "INVALID"})
 		g.Expect(err).To(gmg.HaveOccurred())
+		g.Expect(meta.IsNoMatchError(err)).To(gmg.BeTrue())
 		g.Expect(crt.GetRequestCount()).To(gmg.Equal(5))
 
 		_, err = lazyRestMapper.ResourcesFor(schema.GroupVersionResource{Group: "policy", Version: "v1", Resource: "INVALID"})
 		g.Expect(err).To(gmg.HaveOccurred())
+		g.Expect(meta.IsNoMatchError(err)).To(gmg.BeTrue())
 		g.Expect(crt.GetRequestCount()).To(gmg.Equal(6))
 	})
 
@@ -381,26 +395,32 @@ func TestLazyRestMapperProvider(t *testing.T) {
 
 		_, err = lazyRestMapper.RESTMapping(schema.GroupKind{Group: "apps", Kind: "deployment"}, "INVALID")
 		g.Expect(err).To(gmg.HaveOccurred())
+		g.Expect(meta.IsNoMatchError(err)).To(gmg.BeTrue())
 		g.Expect(crt.GetRequestCount()).To(gmg.Equal(1))
 
 		_, err = lazyRestMapper.RESTMappings(schema.GroupKind{Group: "", Kind: "pod"}, "INVALID")
 		g.Expect(err).To(gmg.HaveOccurred())
+		g.Expect(meta.IsNoMatchError(err)).To(gmg.BeTrue())
 		g.Expect(crt.GetRequestCount()).To(gmg.Equal(2))
 
 		_, err = lazyRestMapper.KindFor(schema.GroupVersionResource{Group: "networking.k8s.io", Version: "INVALID", Resource: "ingresses"})
 		g.Expect(err).To(gmg.HaveOccurred())
+		g.Expect(meta.IsNoMatchError(err)).To(gmg.BeTrue())
 		g.Expect(crt.GetRequestCount()).To(gmg.Equal(3))
 
 		_, err = lazyRestMapper.KindsFor(schema.GroupVersionResource{Group: "authentication.k8s.io", Version: "INVALID", Resource: "tokenreviews"})
 		g.Expect(err).To(gmg.HaveOccurred())
+		g.Expect(meta.IsNoMatchError(err)).To(gmg.BeTrue())
 		g.Expect(crt.GetRequestCount()).To(gmg.Equal(4))
 
 		_, err = lazyRestMapper.ResourceFor(schema.GroupVersionResource{Group: "scheduling.k8s.io", Version: "INVALID", Resource: "priorityclasses"})
 		g.Expect(err).To(gmg.HaveOccurred())
+		g.Expect(meta.IsNoMatchError(err)).To(gmg.BeTrue())
 		g.Expect(crt.GetRequestCount()).To(gmg.Equal(5))
 
 		_, err = lazyRestMapper.ResourcesFor(schema.GroupVersionResource{Group: "policy", Version: "INVALID", Resource: "poddisruptionbudgets"})
 		g.Expect(err).To(gmg.HaveOccurred())
+		g.Expect(meta.IsNoMatchError(err)).To(gmg.BeTrue())
 		g.Expect(crt.GetRequestCount()).To(gmg.Equal(6))
 	})