Convert and construct OpenAPI v2 spec from CRD

staging/src/k8s.io/apiextensions-apiserver/pkg/openapi/conversion.go

+/*
+Copyright 2018 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 openapi
+
+import (
+	"encoding/json"
+
+	"github.com/go-openapi/spec"
+	"k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1"
+)
+
+// ConvertJSONSchemaPropsToOpenAPIv2Schema converts our internal OpenAPI v3 schema
+// (*apiextensions.JSONSchemaProps) to an OpenAPI v2 schema (*spec.Schema).
+// NOTE: we use versioned type (v1beta1) here so that we can properly marshal the object
+// using the JSON tags
+func ConvertJSONSchemaPropsToOpenAPIv2Schema(in *v1beta1.JSONSchemaProps) (*spec.Schema, error) {
+	if in == nil {
+		return nil, nil
+	}
+
+	// Marshal JSONSchemaProps into JSON and unmarshal the data into spec.Schema
+	data, err := json.Marshal(*in)
+	if err != nil {
+		return nil, err
+	}
+	out := new(spec.Schema)
+	if err := out.UnmarshalJSON(data); err != nil {
+		return nil, err
+	}
+	// Remove unsupported fields in OpenAPI v2
+	out.OneOf = nil
+	out.AnyOf = nil
+	out.Not = nil
+	return out, nil
+}

staging/src/k8s.io/apiextensions-apiserver/pkg/openapi/swagger_util.go

+/*
+Copyright 2018 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 openapi
+
+import (
+	"crypto/sha512"
+	"encoding/json"
+	"fmt"
+
+	"github.com/go-openapi/spec"
+	autoscalingv1 "k8s.io/api/autoscaling/v1"
+	"k8s.io/apiextensions-apiserver/pkg/apis/apiextensions"
+	"k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+const (
+	deleteOptionsSchemaRef = "#/definitions/io.k8s.apimachinery.pkg.apis.meta.v1.DeleteOptions"
+	objectMetaSchemaRef    = "#/definitions/io.k8s.apimachinery.pkg.apis.meta.v1.ObjectMeta"
+	scaleSpecSchemaRef     = "#/definitions/io.k8s.api.autoscaling.v1.ScaleSpec"
+	scaleStatusSchemaRef   = "#/definitions/io.k8s.api.autoscaling.v1.ScaleStatus"
+)
+
+var swaggerTypeMetaDescriptions = metav1.TypeMeta{}.SwaggerDoc()
+var swaggerDeleteOptionsDescriptions = metav1.DeleteOptions{}.SwaggerDoc()
+var swaggerListDescriptions = metav1.List{}.SwaggerDoc()
+var swaggerListOptionsDescriptions = metav1.ListOptions{}.SwaggerDoc()
+var swaggerScaleDescriptions = autoscalingv1.Scale{}.SwaggerDoc()
+var swaggerScaleSpecDescriptions = autoscalingv1.ScaleSpec{}.SwaggerDoc()
+var swaggerScaleStatusDescriptions = autoscalingv1.ScaleStatus{}.SwaggerDoc()
+
+// calcSwaggerEtag calculates an etag of the OpenAPI swagger (spec)
+func calcSwaggerEtag(openAPISpec *spec.Swagger) (string, error) {
+	specBytes, err := json.MarshalIndent(openAPISpec, " ", " ")
+	if err != nil {
+		return "", err
+	}
+	return fmt.Sprintf("\"%X\"", sha512.Sum512(specBytes)), nil
+}
+
+// pathParameters constructs the Parameter used by all paths in the CRD swagger (spec)
+func pathParameters() []spec.Parameter {
+	return []spec.Parameter{
+		*spec.QueryParam("pretty").
+			Typed("string", "").
+			UniqueValues().
+			WithDescription("If 'true', then the output is pretty printed."),
+	}
+}
+
+// addDeleteOperationParameters add the body&query parameters used by a delete operation
+func addDeleteOperationParameters(op *spec.Operation) *spec.Operation {
+	return op.
+		AddParam((&spec.Parameter{ParamProps: spec.ParamProps{Schema: spec.RefSchema(deleteOptionsSchemaRef)}}).
+			Named("body").
+			WithLocation("body").
+			AsRequired()).
+		AddParam(spec.QueryParam("dryRun").
+			Typed("string", "").
+			UniqueValues().
+			WithDescription(swaggerDeleteOptionsDescriptions["dryRun"])).
+		AddParam(spec.QueryParam("gracePeriodSeconds").
+			Typed("integer", "").
+			UniqueValues().
+			WithDescription(swaggerDeleteOptionsDescriptions["gracePeriodSeconds"])).
+		AddParam(spec.QueryParam("orphanDependents").
+			Typed("boolean", "").
+			UniqueValues().
+			WithDescription(swaggerDeleteOptionsDescriptions["orphanDependents"])).
+		AddParam(spec.QueryParam("propagationPolicy").
+			Typed("string", "").
+			UniqueValues().
+			WithDescription(swaggerDeleteOptionsDescriptions["propagationPolicy"]))
+}
+
+// addCollectionOperationParameters adds the query parameters used by list and deletecollection
+// operations
+func addCollectionOperationParameters(op *spec.Operation) *spec.Operation {
+	return op.
+		AddParam(spec.QueryParam("continue").
+			Typed("string", "").
+			UniqueValues().
+			WithDescription(swaggerListOptionsDescriptions["continue"])).
+		AddParam(spec.QueryParam("fieldSelector").
+			Typed("string", "").
+			UniqueValues().
+			WithDescription(swaggerListOptionsDescriptions["fieldSelector"])).
+		AddParam(spec.QueryParam("includeUninitialized").
+			Typed("boolean", "").
+			UniqueValues().
+			WithDescription(swaggerListOptionsDescriptions["includeUninitialized"])).
+		AddParam(spec.QueryParam("labelSelector").
+			Typed("string", "").
+			UniqueValues().
+			WithDescription(swaggerListOptionsDescriptions["labelSelector"])).
+		AddParam(spec.QueryParam("limit").
+			Typed("integer", "").
+			UniqueValues().
+			WithDescription(swaggerListOptionsDescriptions["limit"])).
+		AddParam(spec.QueryParam("resourceVersion").
+			Typed("string", "").
+			UniqueValues().
+			WithDescription(swaggerListOptionsDescriptions["resourceVersion"])).
+		AddParam(spec.QueryParam("timeoutSeconds").
+			Typed("integer", "").
+			UniqueValues().
+			WithDescription(swaggerListOptionsDescriptions["timeoutSeconds"])).
+		AddParam(spec.QueryParam("watch").
+			Typed("boolean", "").
+			UniqueValues().
+			WithDescription(swaggerListOptionsDescriptions["watch"]))
+}
+
+// okResponse constructs a 200 OK response with the input object schema reference
+func okResponse(ref string) *spec.Response {
+	return spec.NewResponse().
+		WithDescription("OK").
+		WithSchema(spec.RefSchema(ref))
+}
+
+// createdResponse constructs a 201 Created response with the input object schema reference
+func createdResponse(ref string) *spec.Response {
+	return spec.NewResponse().
+		WithDescription("Created").
+		WithSchema(spec.RefSchema(ref))
+}
+
+// acceptedResponse constructs a 202 Accepted response with the input object schema reference
+func acceptedResponse(ref string) *spec.Response {
+	return spec.NewResponse().
+		WithDescription("Accepted").
+		WithSchema(spec.RefSchema(ref))
+}
+
+// unauthorizedResponse constructs a 401 Unauthorized response
+func unauthorizedResponse() *spec.Response {
+	return spec.NewResponse().
+		WithDescription("Unauthorized")
+}
+
+// scaleSchema constructs the OpenAPI schema for io.k8s.api.autoscaling.v1.Scale objects
+// TODO(roycaihw): this is a hack to let apiExtension apiserver and generic kube-apiserver
+// to have the same io.k8s.api.autoscaling.v1.Scale definition, so that aggregator server won't
+// detect name conflict and create a duplicate io.k8s.api.autoscaling.v1.Scale_V2 schema
+// when aggregating the openapi spec. It would be better if apiExtension apiserver serves
+// identical definition through the same code path (using routes) as generic kube-apiserver.
+func scaleSchema() *spec.Schema {
+	s := new(spec.Schema).
+		WithDescription(swaggerScaleDescriptions[""]).
+		SetProperty("apiVersion", *spec.StringProperty().
+			WithDescription(swaggerTypeMetaDescriptions["apiVersion"])).
+		SetProperty("kind", *spec.StringProperty().
+			WithDescription(swaggerTypeMetaDescriptions["kind"])).
+		SetProperty("metadata", *spec.RefSchema(objectMetaSchemaRef).
+			WithDescription(swaggerScaleDescriptions["metadata"])).
+		SetProperty("spec", *spec.RefSchema(scaleSpecSchemaRef).
+			WithDescription(swaggerScaleDescriptions["spec"])).
+		SetProperty("status", *spec.RefSchema(scaleStatusSchemaRef).
+			WithDescription(swaggerScaleDescriptions["status"]))
+
+	s.AddExtension("x-kubernetes-group-version-kind", []map[string]string{
+		{
+			"group":   "autoscaling",
+			"kind":    "Scale",
+			"version": "v1",
+		},
+	})
+	return s
+}
+
+// scaleSchema constructs the OpenAPI schema for io.k8s.api.autoscaling.v1.ScaleSpec objects
+func scaleSpecSchema() *spec.Schema {
+	return new(spec.Schema).
+		WithDescription(swaggerScaleSpecDescriptions[""]).
+		SetProperty("replicas", *spec.Int32Property().
+			WithDescription(swaggerScaleSpecDescriptions["replicas"]))
+}
+
+// scaleSchema constructs the OpenAPI schema for io.k8s.api.autoscaling.v1.ScaleStatus objects
+func scaleStatusSchema() *spec.Schema {
+	return new(spec.Schema).
+		WithDescription(swaggerScaleStatusDescriptions[""]).
+		WithRequired("replicas").
+		SetProperty("replicas", *spec.Int32Property().
+			WithDescription(swaggerScaleStatusDescriptions["replicas"])).
+		SetProperty("selector", *spec.StringProperty().
+			WithDescription(swaggerScaleStatusDescriptions["selector"]))
+}
+
+// CustomResourceDefinitionOpenAPISpec constructs the OpenAPI spec (swagger) and calculates
+// etag for a given CustomResourceDefinitionSpec.
+// NOTE: in apiserver we general operates on internal types. We are using versioned (v1beta1)
+// validation schema here because we need the json tags to properly marshal the object to
+// JSON.
+func CustomResourceDefinitionOpenAPISpec(crdSpec *apiextensions.CustomResourceDefinitionSpec, version string, validationSchema *v1beta1.CustomResourceValidation) (*spec.Swagger, string, error) {
+	schema := &spec.Schema{}
+	if validationSchema != nil && validationSchema.OpenAPIV3Schema != nil {
+		var err error
+		schema, err = ConvertJSONSchemaPropsToOpenAPIv2Schema(validationSchema.OpenAPIV3Schema)
+		if err != nil {
+			return nil, "", err
+		}
+	}
+	crdSwaggerConstructor, err := NewSwaggerConstructor(schema, crdSpec, version)
+	if err != nil {
+		return nil, "", err
+	}
+	crdOpenAPISpec := crdSwaggerConstructor.ConstructCRDOpenAPISpec()
+	etag, err := calcSwaggerEtag(crdOpenAPISpec)
+	if err != nil {
+		return nil, "", err
+	}
+	return crdOpenAPISpec, etag, nil
+}