CRD openapi v3 -> v2 conversion

staging/publishing/import-restrictions.yaml

@@ -137,6 +137,7 @@
   - k8s.io/client-go
   - k8s.io/component-base
   - k8s.io/klog
+  - k8s.io/kube-openapi
 
 - baseImportPath: "./vendor/k8s.io/kube-openapi/"
   allowedImports:

staging/src/k8s.io/apiextensions-apiserver/BUILD

@@ -47,6 +47,7 @@ filegroup(
         "//staging/src/k8s.io/apiextensions-apiserver/pkg/cmd/server:all-srcs",
         "//staging/src/k8s.io/apiextensions-apiserver/pkg/controller/establish:all-srcs",
         "//staging/src/k8s.io/apiextensions-apiserver/pkg/controller/finalizer:all-srcs",
+        "//staging/src/k8s.io/apiextensions-apiserver/pkg/controller/openapi:all-srcs",
         "//staging/src/k8s.io/apiextensions-apiserver/pkg/controller/status:all-srcs",
         "//staging/src/k8s.io/apiextensions-apiserver/pkg/crdserverscheme:all-srcs",
         "//staging/src/k8s.io/apiextensions-apiserver/pkg/features:all-srcs",

staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/validation/validation.go

@@ -50,8 +50,17 @@ func ValidateCustomResource(customResource interface{}, validator *validate.Sche
 	return nil
 }
 
-// ConvertJSONSchemaProps converts the schema from apiextensions.JSONSchemaPropos to go-openapi/spec.Schema
+// ConvertJSONSchemaProps converts the schema from apiextensions.JSONSchemaPropos to go-openapi/spec.Schema.
 func ConvertJSONSchemaProps(in *apiextensions.JSONSchemaProps, out *spec.Schema) error {
+	return ConvertJSONSchemaPropsWithPostProcess(in, out, nil)
+}
+
+// PostProcessFunc post-processes one node of a spec.Schema.
+type PostProcessFunc func(*spec.Schema) error
+
+// ConvertJSONSchemaPropsWithPostProcess converts the schema from apiextensions.JSONSchemaPropos to go-openapi/spec.Schema
+// and run a post process step on each JSONSchemaProps node.
+func ConvertJSONSchemaPropsWithPostProcess(in *apiextensions.JSONSchemaProps, out *spec.Schema, postProcess PostProcessFunc) error {
 	if in == nil {
 		return nil
 	}
@@ -86,41 +95,43 @@ func ConvertJSONSchemaProps(in *apiextensions.JSONSchemaProps, out *spec.Schema)
 		out.Example = *(in.Example)
 	}
 
-	out.Enum = make([]interface{}, len(in.Enum))
-	for k, v := range in.Enum {
-		out.Enum[k] = v
+	if in.Enum != nil {
+		out.Enum = make([]interface{}, len(in.Enum))
+		for k, v := range in.Enum {
+			out.Enum[k] = v
+		}
 	}
 
-	if err := convertSliceOfJSONSchemaProps(&in.AllOf, &out.AllOf); err != nil {
+	if err := convertSliceOfJSONSchemaProps(&in.AllOf, &out.AllOf, postProcess); err != nil {
 		return err
 	}
-	if err := convertSliceOfJSONSchemaProps(&in.OneOf, &out.OneOf); err != nil {
+	if err := convertSliceOfJSONSchemaProps(&in.OneOf, &out.OneOf, postProcess); err != nil {
 		return err
 	}
-	if err := convertSliceOfJSONSchemaProps(&in.AnyOf, &out.AnyOf); err != nil {
+	if err := convertSliceOfJSONSchemaProps(&in.AnyOf, &out.AnyOf, postProcess); err != nil {
 		return err
 	}
 
 	if in.Not != nil {
 		in, out := &in.Not, &out.Not
 		*out = new(spec.Schema)
-		if err := ConvertJSONSchemaProps(*in, *out); err != nil {
+		if err := ConvertJSONSchemaPropsWithPostProcess(*in, *out, postProcess); err != nil {
 			return err
 		}
 	}
 
 	var err error
-	out.Properties, err = convertMapOfJSONSchemaProps(in.Properties)
+	out.Properties, err = convertMapOfJSONSchemaProps(in.Properties, postProcess)
 	if err != nil {
 		return err
 	}
 
-	out.PatternProperties, err = convertMapOfJSONSchemaProps(in.PatternProperties)
+	out.PatternProperties, err = convertMapOfJSONSchemaProps(in.PatternProperties, postProcess)
 	if err != nil {
 		return err
 	}
 
-	out.Definitions, err = convertMapOfJSONSchemaProps(in.Definitions)
+	out.Definitions, err = convertMapOfJSONSchemaProps(in.Definitions, postProcess)
 	if err != nil {
 		return err
 	}
@@ -135,23 +146,23 @@ func ConvertJSONSchemaProps(in *apiextensions.JSONSchemaProps, out *spec.Schema)
 	if in.AdditionalProperties != nil {
 		in, out := &in.AdditionalProperties, &out.AdditionalProperties
 		*out = new(spec.SchemaOrBool)
-		if err := convertJSONSchemaPropsorBool(*in, *out); err != nil {
+		if err := convertJSONSchemaPropsorBool(*in, *out, postProcess); err != nil {
 			return err
 		}
 	}
 
 	if in.AdditionalItems != nil {
 		in, out := &in.AdditionalItems, &out.AdditionalItems
 		*out = new(spec.SchemaOrBool)
-		if err := convertJSONSchemaPropsorBool(*in, *out); err != nil {
+		if err := convertJSONSchemaPropsorBool(*in, *out, postProcess); err != nil {
 			return err
 		}
 	}
 
 	if in.Items != nil {
 		in, out := &in.Items, &out.Items
 		*out = new(spec.SchemaOrArray)
-		if err := convertJSONSchemaPropsOrArray(*in, *out); err != nil {
+		if err := convertJSONSchemaPropsOrArray(*in, *out, postProcess); err != nil {
 			return err
 		}
 	}
@@ -161,7 +172,7 @@ func ConvertJSONSchemaProps(in *apiextensions.JSONSchemaProps, out *spec.Schema)
 		*out = make(spec.Dependencies, len(*in))
 		for key, val := range *in {
 			newVal := new(spec.SchemaOrStringArray)
-			if err := convertJSONSchemaPropsOrStringArray(&val, newVal); err != nil {
+			if err := convertJSONSchemaPropsOrStringArray(&val, newVal, postProcess); err != nil {
 				return err
 			}
 			(*out)[key] = *newVal
@@ -174,14 +185,20 @@ func ConvertJSONSchemaProps(in *apiextensions.JSONSchemaProps, out *spec.Schema)
 		out.ExternalDocs.URL = in.ExternalDocs.URL
 	}
 
+	if postProcess != nil {
+		if err := postProcess(out); err != nil {
+			return err
+		}
+	}
+
 	return nil
 }
 
-func convertSliceOfJSONSchemaProps(in *[]apiextensions.JSONSchemaProps, out *[]spec.Schema) error {
+func convertSliceOfJSONSchemaProps(in *[]apiextensions.JSONSchemaProps, out *[]spec.Schema, postProcess PostProcessFunc) error {
 	if in != nil {
 		for _, jsonSchemaProps := range *in {
 			schema := spec.Schema{}
-			if err := ConvertJSONSchemaProps(&jsonSchemaProps, &schema); err != nil {
+			if err := ConvertJSONSchemaPropsWithPostProcess(&jsonSchemaProps, &schema, postProcess); err != nil {
 				return err
 			}
 			*out = append(*out, schema)
@@ -190,58 +207,60 @@ func convertSliceOfJSONSchemaProps(in *[]apiextensions.JSONSchemaProps, out *[]s
 	return nil
 }
 
-func convertMapOfJSONSchemaProps(in map[string]apiextensions.JSONSchemaProps) (map[string]spec.Schema, error) {
+func convertMapOfJSONSchemaProps(in map[string]apiextensions.JSONSchemaProps, postProcess PostProcessFunc) (map[string]spec.Schema, error) {
+	if in == nil {
+		return nil, nil
+	}
+
 	out := make(map[string]spec.Schema)
-	if len(in) != 0 {
-		for k, jsonSchemaProps := range in {
-			schema := spec.Schema{}
-			if err := ConvertJSONSchemaProps(&jsonSchemaProps, &schema); err != nil {
-				return nil, err
-			}
-			out[k] = schema
+	for k, jsonSchemaProps := range in {
+		schema := spec.Schema{}
+		if err := ConvertJSONSchemaPropsWithPostProcess(&jsonSchemaProps, &schema, postProcess); err != nil {
+			return nil, err
 		}
+		out[k] = schema
 	}
 	return out, nil
 }
 
-func convertJSONSchemaPropsOrArray(in *apiextensions.JSONSchemaPropsOrArray, out *spec.SchemaOrArray) error {
+func convertJSONSchemaPropsOrArray(in *apiextensions.JSONSchemaPropsOrArray, out *spec.SchemaOrArray, postProcess PostProcessFunc) error {
 	if in.Schema != nil {
 		in, out := &in.Schema, &out.Schema
 		*out = new(spec.Schema)
-		if err := ConvertJSONSchemaProps(*in, *out); err != nil {
+		if err := ConvertJSONSchemaPropsWithPostProcess(*in, *out, postProcess); err != nil {
 			return err
 		}
 	}
 	if in.JSONSchemas != nil {
 		in, out := &in.JSONSchemas, &out.Schemas
 		*out = make([]spec.Schema, len(*in))
 		for i := range *in {
-			if err := ConvertJSONSchemaProps(&(*in)[i], &(*out)[i]); err != nil {
+			if err := ConvertJSONSchemaPropsWithPostProcess(&(*in)[i], &(*out)[i], postProcess); err != nil {
 				return err
 			}
 		}
 	}
 	return nil
 }
 
-func convertJSONSchemaPropsorBool(in *apiextensions.JSONSchemaPropsOrBool, out *spec.SchemaOrBool) error {
+func convertJSONSchemaPropsorBool(in *apiextensions.JSONSchemaPropsOrBool, out *spec.SchemaOrBool, postProcess PostProcessFunc) error {
 	out.Allows = in.Allows
 	if in.Schema != nil {
 		in, out := &in.Schema, &out.Schema
 		*out = new(spec.Schema)
-		if err := ConvertJSONSchemaProps(*in, *out); err != nil {
+		if err := ConvertJSONSchemaPropsWithPostProcess(*in, *out, postProcess); err != nil {
 			return err
 		}
 	}
 	return nil
 }
 
-func convertJSONSchemaPropsOrStringArray(in *apiextensions.JSONSchemaPropsOrStringArray, out *spec.SchemaOrStringArray) error {
+func convertJSONSchemaPropsOrStringArray(in *apiextensions.JSONSchemaPropsOrStringArray, out *spec.SchemaOrStringArray, postProcess PostProcessFunc) error {
 	out.Property = in.Property
 	if in.Schema != nil {
 		in, out := &in.Schema, &out.Schema
 		*out = new(spec.Schema)
-		if err := ConvertJSONSchemaProps(*in, *out); err != nil {
+		if err := ConvertJSONSchemaPropsWithPostProcess(*in, *out, postProcess); err != nil {
 			return err
 		}
 	}

staging/src/k8s.io/apiextensions-apiserver/pkg/controller/openapi/BUILD

@@ -0,0 +1,45 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["conversion.go"],
+    importmap = "k8s.io/kubernetes/vendor/k8s.io/apiextensions-apiserver/pkg/controller/openapi",
+    importpath = "k8s.io/apiextensions-apiserver/pkg/controller/openapi",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions:go_default_library",
+        "//staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/validation:go_default_library",
+        "//vendor/github.com/go-openapi/spec:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["conversion_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions:go_default_library",
+        "//staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/util/diff:go_default_library",
+        "//vendor/github.com/go-openapi/spec:go_default_library",
+        "//vendor/github.com/google/gofuzz:go_default_library",
+        "//vendor/github.com/googleapis/gnostic/OpenAPIv2:go_default_library",
+        "//vendor/github.com/googleapis/gnostic/compiler:go_default_library",
+        "//vendor/gopkg.in/yaml.v2:go_default_library",
+        "//vendor/k8s.io/kube-openapi/pkg/util/proto:go_default_library",
+    ],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+    visibility = ["//visibility:public"],
+)

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

@@ -0,0 +1,118 @@
+/*
+Copyright 2019 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 (
+	"strings"
+
+	"github.com/go-openapi/spec"
+
+	"k8s.io/apiextensions-apiserver/pkg/apis/apiextensions"
+	"k8s.io/apiextensions-apiserver/pkg/apiserver/validation"
+)
+
+// ConvertJSONSchemaPropsToOpenAPIv2Schema converts our internal OpenAPI v3 schema
+// (*apiextensions.JSONSchemaProps) to an OpenAPI v2 schema (*spec.Schema).
+func ConvertJSONSchemaPropsToOpenAPIv2Schema(in *apiextensions.JSONSchemaProps) (*spec.Schema, error) {
+	if in == nil {
+		return nil, nil
+	}
+
+	// dirty hack to temporarily set the type at the root. See continuation at the func bottom.
+	// TODO: remove for Kubernetes 1.15
+	oldRootType := in.Type
+	if len(in.Type) == 0 {
+		in.Type = "object"
+	}
+
+	// Remove unsupported fields in OpenAPI v2 recursively
+	out := new(spec.Schema)
+	validation.ConvertJSONSchemaPropsWithPostProcess(in, out, func(p *spec.Schema) error {
+		p.OneOf = nil
+		// TODO(roycaihw): preserve cases where we only have one subtree in AnyOf, same for OneOf
+		p.AnyOf = nil
+		p.Not = nil
+
+		// TODO: drop everything below in 1.15 when we have passed one version skew towards kube-openapi in <1.14, which rejects valid openapi schemata
+
+		if p.Ref.String() != "" {
+			// https://github.com/kubernetes/kube-openapi/pull/143/files#diff-62afddb578e9db18fb32ffb6b7802d92R95
+			p.Properties = nil
+
+			// https://github.com/kubernetes/kube-openapi/pull/143/files#diff-62afddb578e9db18fb32ffb6b7802d92R99
+			p.Type = nil
+
+			// https://github.com/kubernetes/kube-openapi/pull/143/files#diff-62afddb578e9db18fb32ffb6b7802d92R104
+			if !strings.HasPrefix(p.Ref.String(), "#/definitions/") {
+				p.Ref = spec.Ref{}
+			}
+		}
+
+		if len(p.Type) > 1 {
+			// https://github.com/kubernetes/kube-openapi/pull/143/files#diff-62afddb578e9db18fb32ffb6b7802d92R272
+			// We also set Properties to null to enforce parseArbitrary at https://github.com/kubernetes/kube-openapi/blob/814a8073653e40e0e324205d093770d4e7bb811f/pkg/util/proto/document.go#L247
+			p.Type = nil
+			p.Properties = nil
+		} else if len(p.Type) == 1 {
+			switch p.Type[0] {
+			case "null":
+				// https://github.com/kubernetes/kube-openapi/pull/143/files#diff-ce77fea74b9dd098045004410023e0c3R219
+				p.Type = nil
+			case "array":
+				// https://github.com/kubernetes/kube-openapi/pull/143/files#diff-62afddb578e9db18fb32ffb6b7802d92R183
+				// https://github.com/kubernetes/kube-openapi/pull/143/files#diff-62afddb578e9db18fb32ffb6b7802d92R184
+				if p.Items == nil || (p.Items.Schema == nil && len(p.Items.Schemas) != 1) {
+					p.Type = nil
+					p.Items = nil
+				}
+			}
+		} else {
+			// https://github.com/kubernetes/kube-openapi/pull/143/files#diff-62afddb578e9db18fb32ffb6b7802d92R248
+			p.Properties = nil
+		}
+
+		// normalize items
+		if p.Items != nil && len(p.Items.Schemas) == 1 {
+			p.Items = &spec.SchemaOrArray{Schema: &p.Items.Schemas[0]}
+		}
+
+		// general fixups not supported by gnostic
+		p.ID = ""
+		p.Schema = ""
+		p.Definitions = nil
+		p.AdditionalItems = nil
+		p.Dependencies = nil
+		p.PatternProperties = nil
+		if p.ExternalDocs != nil && len(p.ExternalDocs.URL) == 0 {
+			p.ExternalDocs = nil
+		}
+		if p.Items != nil && p.Items.Schemas != nil {
+			p.Items = nil
+		}
+
+		return nil
+	})
+
+	// restore root level type in input, and remove it in output if we had added it
+	// TODO: remove with Kubernetes 1.15
+	in.Type = oldRootType
+	if len(oldRootType) == 0 {
+		out.Type = nil
+	}
+
+	return out, nil
+}