cue/cmd: import crd for importing Kubernetes CustomResourceDefinitions

cmd/cue/cmd/get_crd.go

@@ -0,0 +1,93 @@
+// Copyright 2023 The CUE 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 cmd
+
+import (
+	"os"
+	"path"
+	"sort"
+	"strings"
+
+	"cuelang.org/go/encoding/crd"
+)
+
+// func newCrdCmd(c *Command) *cobra.Command {
+// 	cmd := &cobra.Command{
+// 		Use:   "crd [files]",
+// 		Short: "add Kubernetes CustomResourceDefinition dependencies to the current module",
+// 		Long: `crd converts Kubernetes resources defined by a CustomResourceDefinition into CUE definitions
+
+// The command "cue get crd" converts the Kubernetes CustomResourceDefinition
+// to CUE. The retrieved definitions are put in the CUE module's pkg
+// directory at the API group name of the corresponding resource. The converted
+// definitions are available to any CUE file within the CUE module by using
+// this name.
+
+// The CustomResourceDefinition is converted to CUE based on how it would be
+// interpreted by the Kubernetes API server. Definitions for a CRD with group
+// name "myresource.example.com" and version "v1" will be written to a CUE
+// file named myresource.example.com/v1/types_crd_gen.cue.
+
+// It is safe for users to add additional files to the generated directories,
+// as long as their name does not end with _gen.*.
+
+// Rules of Converting CustomResourceDefinitions to CUE
+
+// CustomResourceDefinitions are converted to cue structs adhering to the following conventions:
+
+// 	- OpenAPIv3 schema is imported the same as "cue import openapi".
+
+// 	- The @x-kubernetes-validation attribute is added if the field utilizes the "x-kubernetes-validation" extension.
+// `,
+
+// 		RunE: mkRunE(c, runImportCRD),
+// 	}
+
+// 	return cmd
+// }
+
+func runImportCRD(cmd *Command, args []string) error {
+	decoder := crd.NewExtractor(cmd.ctx, "// cue get crd "+strings.Join(args, " "))
+
+	data, err := os.ReadFile(args[0])
+	if err != nil {
+		return err
+	}
+
+	crds, err := decoder.Instances(data)
+	if err != nil {
+		return err
+	}
+
+	// Sort the resulting definitions based on file names.
+	keys := make([]string, 0, len(crds))
+	for k := range crds {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+
+	for _, k := range keys {
+		dstDir := path.Join("cue.mod", "gen", k)
+		if err := os.MkdirAll(dstDir, os.ModePerm); err != nil {
+			return err
+		}
+
+		if err := os.WriteFile(path.Join(dstDir, "types_gen.cue"), crds[k], 0644); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}

cmd/cue/cmd/import.go

@@ -290,6 +290,8 @@ func runImport(cmd *Command, args []string) (err error) {
 			c.fileFilter = `\.(json|jsonl|ldjson)$`
 		case "yaml":
 			c.fileFilter = `\.(yaml|yml)$`
+		case "crd":
+			return runImportCRD(cmd, args)
 		case "text":
 			c.fileFilter = `\.txt$`
 		case "binary":

cue/build/file.go

@@ -66,10 +66,11 @@ const (
 	// the info.title and info.version fields.
 	//
 	// In all other cases, the underlying data is interpreted as is.
-	Auto         Interpretation = "auto"
-	JSONSchema   Interpretation = "jsonschema"
-	OpenAPI      Interpretation = "openapi"
-	ProtobufJSON Interpretation = "pb"
+	Auto                     Interpretation = "auto"
+	JSONSchema               Interpretation = "jsonschema"
+	OpenAPI                  Interpretation = "openapi"
+	ProtobufJSON             Interpretation = "pb"
+	CustomResourceDefinition Interpretation = "crd"
 )
 
 // A Form specifies the form in which a program should be represented.