kubectl OpenAPI support

Kubernetes-commit: 212c2a3a7217ff7e0a7c895582c7a25d03ac7f8c

discovery/discovery_client.go

@@ -25,6 +25,8 @@ import (
 
 	"github.com/emicklei/go-restful/swagger"
 
+	"github.com/go-openapi/loads"
+	"github.com/go-openapi/spec"
 	"k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
@@ -47,6 +49,7 @@ type DiscoveryInterface interface {
 	ServerResourcesInterface
 	ServerVersionInterface
 	SwaggerSchemaInterface
+	OpenAPISchemaInterface
 }
 
 // CachedDiscoveryInterface is a DiscoveryInterface with cache invalidation and freshness.
@@ -91,6 +94,12 @@ type SwaggerSchemaInterface interface {
 	SwaggerSchema(version schema.GroupVersion) (*swagger.ApiDeclaration, error)
 }
 
+// OpenAPISchemaInterface has a method to retrieve the open API schema.
+type OpenAPISchemaInterface interface {
+	// OpenAPISchema retrieves and parses the swagger API schema the server supports.
+	OpenAPISchema() (*spec.Swagger, error)
+}
+
 // DiscoveryClient implements the functions that discover server-supported API groups,
 // versions and resources.
 type DiscoveryClient struct {
@@ -332,6 +341,7 @@ func (d *DiscoveryClient) ServerVersion() (*version.Info, error) {
 }
 
 // SwaggerSchema retrieves and parses the swagger API schema the server supports.
+// TODO: Replace usages with Open API.  Tracked in https://github.com/kubernetes/kubernetes/issues/44589
 func (d *DiscoveryClient) SwaggerSchema(version schema.GroupVersion) (*swagger.ApiDeclaration, error) {
 	if version.Empty() {
 		return nil, fmt.Errorf("groupVersion cannot be empty")
@@ -365,6 +375,21 @@ func (d *DiscoveryClient) SwaggerSchema(version schema.GroupVersion) (*swagger.A
 	return &schema, nil
 }
 
+// OpenAPISchema fetches the open api schema using a rest client and parses the json.
+// Warning: this is very expensive (~1.2s)
+func (d *DiscoveryClient) OpenAPISchema() (*spec.Swagger, error) {
+	data, err := d.restClient.Get().AbsPath("/swagger.json").Do().Raw()
+	if err != nil {
+		return nil, err
+	}
+	msg := json.RawMessage(data)
+	doc, err := loads.Analyzed(msg, "")
+	if err != nil {
+		return nil, err
+	}
+	return doc.Spec(), err
+}
+
 // withRetries retries the given recovery function in case the groups supported by the server change after ServerGroup() returns.
 func withRetries(maxRetries int, f func(failEarly bool) ([]*metav1.APIResourceList, error)) ([]*metav1.APIResourceList, error) {
 	var result []*metav1.APIResourceList

discovery/discovery_client_test.go

@@ -18,6 +18,7 @@ package discovery_test
 
 import (
 	"encoding/json"
+	"fmt"
 	"net/http"
 	"net/http/httptest"
 	"reflect"
@@ -25,6 +26,7 @@ import (
 
 	"github.com/emicklei/go-restful/swagger"
 
+	"github.com/go-openapi/spec"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/apimachinery/pkg/util/sets"
@@ -325,6 +327,81 @@ func TestGetSwaggerSchemaFail(t *testing.T) {
 	}
 }
 
+var returnedOpenAPI = spec.Swagger{
+	SwaggerProps: spec.SwaggerProps{
+		Definitions: spec.Definitions{
+			"fake.type.1": spec.Schema{
+				SchemaProps: spec.SchemaProps{
+					Properties: map[string]spec.Schema{
+						"count": {
+							SchemaProps: spec.SchemaProps{
+								Type: []string{"integer"},
+							},
+						},
+					},
+				},
+			},
+			"fake.type.2": spec.Schema{
+				SchemaProps: spec.SchemaProps{
+					Properties: map[string]spec.Schema{
+						"count": {
+							SchemaProps: spec.SchemaProps{
+								Type: []string{"array"},
+								Items: &spec.SchemaOrArray{
+									Schema: &spec.Schema{
+										SchemaProps: spec.SchemaProps{
+											Type: []string{"string"},
+										},
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	},
+}
+
+func openapiSchemaFakeServer() (*httptest.Server, error) {
+	var sErr error
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+		if req.URL.Path != "/swagger.json" {
+			sErr = fmt.Errorf("Unexpected url %v", req.URL)
+		}
+		if req.Method != "GET" {
+			sErr = fmt.Errorf("Unexpected method %v", req.Method)
+		}
+
+		output, err := json.Marshal(returnedOpenAPI)
+		if err != nil {
+			sErr = err
+			return
+		}
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+		w.Write(output)
+	}))
+	return server, sErr
+}
+
+func TestGetOpenAPISchema(t *testing.T) {
+	server, err := openapiSchemaFakeServer()
+	if err != nil {
+		t.Errorf("unexpected error starting fake server: %v", err)
+	}
+	defer server.Close()
+
+	client := NewDiscoveryClientForConfigOrDie(&restclient.Config{Host: server.URL})
+	got, err := client.OpenAPISchema()
+	if err != nil {
+		t.Fatalf("unexpected error getting openapi: %v", err)
+	}
+	if e, a := returnedOpenAPI, *got; !reflect.DeepEqual(e, a) {
+		t.Errorf("expected %v, got %v", e, a)
+	}
+}
+
 func TestServerPreferredResources(t *testing.T) {
 	stable := metav1.APIResourceList{
 		GroupVersion: "v1",

discovery/fake/discovery.go

@@ -21,6 +21,7 @@ import (
 
 	"github.com/emicklei/go-restful/swagger"
 
+	"github.com/go-openapi/spec"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/apimachinery/pkg/version"
@@ -92,6 +93,8 @@ func (c *FakeDiscovery) SwaggerSchema(version schema.GroupVersion) (*swagger.Api
 	return &swagger.ApiDeclaration{}, nil
 }
 
+func (c *FakeDiscovery) OpenAPISchema() (*spec.Swagger, error) { return &spec.Swagger{}, nil }
+
 func (c *FakeDiscovery) RESTClient() restclient.Interface {
 	return nil
 }

discovery/restmapper_test.go

@@ -30,6 +30,7 @@ import (
 	"k8s.io/client-go/rest/fake"
 
 	"github.com/emicklei/go-restful/swagger"
+	"github.com/go-openapi/spec"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -347,3 +348,7 @@ func (c *fakeCachedDiscoveryInterface) ServerVersion() (*version.Info, error) {
 func (c *fakeCachedDiscoveryInterface) SwaggerSchema(version schema.GroupVersion) (*swagger.ApiDeclaration, error) {
 	return &swagger.ApiDeclaration{}, nil
 }
+
+func (c *fakeCachedDiscoveryInterface) OpenAPISchema() (*spec.Swagger, error) {
+	return &spec.Swagger{}, nil
+}