[release-0.15] 🐛 fix unspecified KindsFor version (#2347)

* Fix unspecified KindsFor version

* Dont allocate empty list

Co-authored-by: Alvaro Aleman <alvaroaleman@users.noreply.github.com>

* Test all four relevant interface methods, and do not assert count

* Attempt to format correctly in web editor

* Remove request count asserts

* Remove non-version item asserts

---------

Co-authored-by: Amund Tenstad <github@amund.io>
Co-authored-by: Alvaro Aleman <alvaroaleman@users.noreply.github.com>

pkg/client/apiutil/restmapper.go

@@ -152,6 +152,12 @@ func (m *mapper) getMapper() meta.RESTMapper {
 // addKnownGroupAndReload reloads the mapper with updated information about missing API group.
 // versions can be specified for partial updates, for instance for v1beta1 version only.
 func (m *mapper) addKnownGroupAndReload(groupName string, versions ...string) error {
+	// versions will here be [""] if the forwarded Version value of
+	// GroupVersionResource (in calling method) was not specified.
+	if len(versions) == 1 && versions[0] == "" {
+		versions = nil
+	}
+
 	// If no specific versions are set by user, we will scan all available ones for the API group.
 	// This operation requires 2 requests: /api and /apis, but only once. For all subsequent calls
 	// this data will be taken from cache.

pkg/client/apiutil/restmapper_test.go

@@ -404,6 +404,34 @@ func TestLazyRestMapperProvider(t *testing.T) {
 		g.Expect(crt.GetRequestCount()).To(gmg.Equal(6))
 	})
 
+	t.Run("LazyRESTMapper should work correctly if the version isn't specified", func(t *testing.T) {
+		g := gmg.NewWithT(t)
+
+		httpClient, err := rest.HTTPClientFor(restCfg)
+		g.Expect(err).NotTo(gmg.HaveOccurred())
+
+		lazyRestMapper, err := apiutil.NewDynamicRESTMapper(restCfg, httpClient)
+		g.Expect(err).NotTo(gmg.HaveOccurred())
+
+		kind, err := lazyRestMapper.KindFor(schema.GroupVersionResource{Group: "networking.k8s.io", Resource: "ingress"})
+		g.Expect(err).NotTo(gmg.HaveOccurred())
+		g.Expect(kind.Version).ToNot(gmg.BeEmpty())
+
+		kinds, err := lazyRestMapper.KindsFor(schema.GroupVersionResource{Group: "authentication.k8s.io", Resource: "tokenreviews"})
+		g.Expect(err).NotTo(gmg.HaveOccurred())
+		g.Expect(kinds).ToNot(gmg.BeEmpty())
+		g.Expect(kinds[0].Version).ToNot(gmg.BeEmpty())
+
+		resorce, err := lazyRestMapper.ResourceFor(schema.GroupVersionResource{Group: "scheduling.k8s.io", Resource: "priorityclasses"})
+		g.Expect(err).NotTo(gmg.HaveOccurred())
+		g.Expect(resorce.Version).ToNot(gmg.BeEmpty())
+
+		resorces, err := lazyRestMapper.ResourcesFor(schema.GroupVersionResource{Group: "policy", Resource: "poddisruptionbudgets"})
+		g.Expect(err).NotTo(gmg.HaveOccurred())
+		g.Expect(kinds).ToNot(gmg.BeEmpty())
+		g.Expect(resorces[0].Version).ToNot(gmg.BeEmpty())
+	})
+
 	t.Run("LazyRESTMapper can fetch CRDs if they were created at runtime", func(t *testing.T) {
 		g := gmg.NewWithT(t)