kubectl explain should work for both cluster and namespace resources and without a GET method

Kubernetes-commit: 7f4c187ab26fc8b96a091068ee9c84fa447b9291

pkg/explain/v2/funcs.go

@@ -185,6 +185,9 @@ func WithBuiltinTemplateFuncs(tmpl *template.Template) *template.Template {
 
 			return copyDict, nil
 		},
+		"list": func(values ...any) ([]any, error) {
+			return values, nil
+		},
 		"add": func(value, operand int) int {
 			return value + operand
 		},

pkg/explain/v2/templates/plaintext.tmpl

@@ -2,13 +2,33 @@
 {{- $prefix := (ternary "/api" (join "" "/apis/" $.GVR.Group) (not $.GVR.Group)) -}}
 
 {{- /* Search both cluster-scoped and namespaced-scoped paths for the GVR to find its GVK */ -}}
-{{- /* Looks for path /apis/<group>/<version>/<resource> or /apis/<group>/<version>/<version>/namespaces/{namespace}/<resource> */ -}}
+{{- /* Also search for paths with {name} component in case the list path is missing */ -}}
+{{- /* Looks for the following paths: */ -}}
+{{- /* /apis/<group>/<version>/<resource> */ -}}
+{{- /* /apis/<group>/<version>/<resource>/{name} */ -}}
+{{- /* /apis/<group>/<version>/namespaces/{namespace}/<resource> */ -}}
+{{- /* /apis/<group>/<version>/namespaces/{namespace}/<resource>/{name} */ -}}
+{{- /* Also search for get verb paths in case list verb is missing */ -}}
 {{- $clusterScopedSearchPath :=  join "/" $prefix $.GVR.Version $.GVR.Resource -}}
-{{- $namespaceScopedSearchPath := join "/" $prefix $.GVR.Version "namespaces" "\\{namespace\\}" $.GVR.Resource -}}
+{{- $clusterScopedNameSearchPath :=  join "/" $prefix $.GVR.Version $.GVR.Resource "{name}" -}}
-{{- $path := or (index $.Document "paths" $clusterScopedSearchPath) (index $.Document "paths" $clusterScopedSearchPath) -}}
+{{- $namespaceScopedSearchPath := join "/" $prefix $.GVR.Version "namespaces" "{namespace}" $.GVR.Resource -}}
+{{- $namespaceScopedNameSearchPath := join "/" $prefix $.GVR.Version "namespaces" "{namespace}" $.GVR.Resource "{name}" -}}
+{{- $gvk := "" -}}
 
 {{- /* Pull GVK from operation */ -}}
-{{- with $gvk := and $path (index $path "get" "x-kubernetes-group-version-kind") -}}
+{{- range $index, $searchPath := (list $clusterScopedSearchPath $clusterScopedNameSearchPath $namespaceScopedSearchPath $namespaceScopedNameSearchPath) -}}
+    {{- with $resourcePathElement := index $.Document "paths" $searchPath -}}
+        {{- range $methodIndex, $method := (list "get" "post" "put" "patch" "delete") -}}
+            {{- with $resourceMethodPathElement := index $resourcePathElement $method -}}
+                {{- with $gvk = index $resourceMethodPathElement "x-kubernetes-group-version-kind" -}}
+                    {{- break -}}
+                {{- end -}}
+            {{- end -}}
+        {{- end -}}
+    {{- end -}}
+{{- end -}}
+
+{{- with $gvk -}}
     {{- if $gvk.group -}}
         GROUP:      {{ $gvk.group }}{{"\n" -}}
     {{- end -}}

pkg/explain/v2/templates/plaintext_test.go

@@ -41,17 +41,46 @@ var (
 	//go:embed apiextensions.k8s.io_v1.json
 	apiextensionsJSON string
 
+	//go:embed batch.k8s.io_v1.json
+	batchJSON string
+
 	apiExtensionsV1OpenAPI map[string]interface{} = func() map[string]interface{} {
 		var res map[string]interface{}
 		utilruntime.Must(json.Unmarshal([]byte(apiextensionsJSON), &res))
 		return res
 	}()
 
+	apiExtensionsV1OpenAPIWithoutListVerb map[string]interface{} = func() map[string]interface{} {
+		var res map[string]interface{}
+		utilruntime.Must(json.Unmarshal([]byte(apiextensionsJSON), &res))
+		paths := res["paths"].(map[string]interface{})
+		delete(paths, "/apis/apiextensions.k8s.io/v1/customresourcedefinitions")
+		return res
+	}()
+
 	apiExtensionsV1OpenAPISpec spec3.OpenAPI = func() spec3.OpenAPI {
 		var res spec3.OpenAPI
 		utilruntime.Must(json.Unmarshal([]byte(apiextensionsJSON), &res))
 		return res
 	}()
+
+	batchV1OpenAPI map[string]interface{} = func() map[string]interface{} {
+		var res map[string]interface{}
+		utilruntime.Must(json.Unmarshal([]byte(batchJSON), &res))
+		return res
+	}()
+
+	batchV1OpenAPIWithoutListVerb map[string]interface{} = func() map[string]interface{} {
+		var res map[string]interface{}
+		utilruntime.Must(json.Unmarshal([]byte(batchJSON), &res))
+		paths := res["paths"].(map[string]interface{})
+		delete(paths, "/apis/batch/v1/jobs")
+		delete(paths, "/apis/batch/v1/namespaces/{namespace}/jobs")
+
+		delete(paths, "/apis/batch/v1/cronjobs")
+		delete(paths, "/apis/batch/v1/namespaces/{namespace}/cronjobs/{name}")
+		return res
+	}()
 )
 
 type testCase struct {
@@ -143,6 +172,74 @@ func TestPlaintext(t *testing.T) {
 				checkContains("CustomResourceDefinition represents a resource that should be exposed"),
 			},
 		},
+		{
+			// Test basic ability to find a namespaced GVR and print its description
+			Name: "SchemaFoundNamespaced",
+			Context: v2.TemplateContext{
+				Document: batchV1OpenAPI,
+				GVR: schema.GroupVersionResource{
+					Group:    "batch",
+					Version:  "v1",
+					Resource: "jobs",
+				},
+				FieldPath: nil,
+				Recursive: false,
+			},
+			Checks: []check{
+				checkContains("Job represents the configuration of a single job"),
+			},
+		},
+		{
+			// Test basic ability to find a GVR without a list verb and print its description
+			Name: "SchemaFoundWithoutListVerb",
+			Context: v2.TemplateContext{
+				Document: apiExtensionsV1OpenAPIWithoutListVerb,
+				GVR: schema.GroupVersionResource{
+					Group:    "apiextensions.k8s.io",
+					Version:  "v1",
+					Resource: "customresourcedefinitions",
+				},
+				FieldPath: nil,
+				Recursive: false,
+			},
+			Checks: []check{
+				checkContains("CustomResourceDefinition represents a resource that should be exposed"),
+			},
+		},
+		{
+			// Test basic ability to find a namespaced GVR without a list verb and print its description
+			Name: "SchemaFoundNamespacedWithoutListVerb",
+			Context: v2.TemplateContext{
+				Document: batchV1OpenAPIWithoutListVerb,
+				GVR: schema.GroupVersionResource{
+					Group:    "batch",
+					Version:  "v1",
+					Resource: "jobs",
+				},
+				FieldPath: nil,
+				Recursive: false,
+			},
+			Checks: []check{
+				checkContains("Job represents the configuration of a single job"),
+			},
+		},
+		{
+			// Test basic ability to find a namespaced GVR without a top level list verb and print its description
+			Name: "SchemaFoundNamespacedWithoutTopLevelListVerb",
+			Context: v2.TemplateContext{
+				Document: batchV1OpenAPIWithoutListVerb,
+				GVR: schema.GroupVersionResource{
+					Group:    "batch",
+					Version:  "v1",
+					Resource: "cronjobs",
+				},
+				FieldPath: nil,
+				Recursive: false,
+			},
+			Checks: []check{
+				checkContains("CronJob represents the configuration of a single cron job"),
+			},
+		},
 		{
 			// Test that shows trying to find a non-existent field path of an existing
 			// schema