Fix apache#1537: generate json schema for full Kubernetes resources

cmd/util/json-schema-gen/main.go

@@ -0,0 +1,141 @@
+/*
+Licensed to the Apache Software Foundation (ASF) under one or more
+contributor license agreements.  See the NOTICE file distributed with
+this work for additional information regarding copyright ownership.
+The ASF licenses this file to You 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 main
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"reflect"
+	"strings"
+
+	"sigs.k8s.io/yaml"
+)
+
+func main() {
+	if len(os.Args) != 6 {
+		fmt.Println(`Use "json-schema-gen <crd> <schema> <path> <isArray> <destination>`)
+		os.Exit(1)
+	}
+	crd := os.Args[1]
+	schema := os.Args[2]
+	path := os.Args[3]
+	isArray := "true" == os.Args[4]
+	destination := os.Args[5]
+
+	if err := generate(crd, schema, path, isArray, destination); err != nil {
+		panic(err)
+	}
+}
+
+func generate(crd, schema, path string, isArray bool, destination string) error {
+	crdData, err := ioutil.ReadFile(crd)
+	if err != nil {
+		return err
+	}
+
+	var crdObj map[string]interface{}
+	if err := yaml.Unmarshal(crdData, &crdObj); err != nil {
+		return err
+	}
+
+	bigSchema := getSchemaFromCRD(crdObj)
+	ref := bigSchema
+	for _, p := range pathComponents(path) {
+		ref = ref["properties"].(map[string]interface{})[p].(map[string]interface{})
+	}
+
+	dslSchema, err := loadDSLSchema(schema)
+	dslObjectSchema := dslSchema["items"].(map[string]interface{})
+	if err != nil {
+		return err
+	}
+	if !isArray && dslSchema["type"] == "array" {
+		dslSchema = dslObjectSchema
+	}
+
+	// merge schemas
+	for k, v := range dslSchema {
+		if k != "definitions" {
+			ref[k] = v
+		}
+	}
+	// readd definitions
+	if _, alreadyHasDefs := bigSchema["definitions"]; alreadyHasDefs {
+		panic("unexpected definitions found in CRD")
+	}
+	bigSchema["definitions"] = dslObjectSchema["definitions"]
+	rebaseRefs(dslSchema)
+
+	result, err := json.MarshalIndent(bigSchema, "", "  ")
+	if err != nil {
+		return err
+	}
+	return ioutil.WriteFile(destination, result, 0666)
+}
+
+func remapRef(ref string) string {
+	return "#" + strings.TrimPrefix(ref, "#/items")
+}
+
+func rebaseRefs(schema map[string]interface{}) {
+	for k, v := range schema {
+		if k == "$ref" && reflect.TypeOf(v).Kind() == reflect.String {
+			schema[k] = remapRef(fmt.Sprintf("%v", v))
+		} else if reflect.TypeOf(v).Kind() == reflect.Map {
+			rebaseRefs(v.(map[string]interface{}))
+		} else if reflect.TypeOf(v).Kind() == reflect.Slice {
+			for _, vv := range v.([]interface{}) {
+				if reflect.TypeOf(vv).Kind() == reflect.Map {
+					rebaseRefs(vv.(map[string]interface{}))
+				}
+			}
+		}
+	}
+}
+
+func loadDSLSchema(schema string) (map[string]interface{}, error) {
+	content, err := ioutil.ReadFile(schema)
+	if err != nil {
+		return nil, err
+	}
+	var dslSchema map[string]interface{}
+	if err := json.Unmarshal(content, &dslSchema); err != nil {
+		return nil, err
+	}
+	return dslSchema, nil
+}
+
+func getSchemaFromCRD(crd map[string]interface{}) map[string]interface{} {
+	res := crd["spec"].(map[string]interface{})
+	res = res["validation"].(map[string]interface{})
+	res = res["openAPIV3Schema"].(map[string]interface{})
+	return res
+}
+
+func pathComponents(path string) []string {
+	res := make([]string, 0)
+	for _, p := range strings.Split(path, ".") {
+		if len(strings.TrimSpace(p)) == 0 {
+			continue
+		}
+		res = append(res, p)
+	}
+	return res
+}