support yaml formatted openapi schema (#4017)

* support yaml formatted openapi schema

* suggested changes

api/krusty/openapicustomschema_test.go

@@ -17,6 +17,11 @@ func writeTestSchema(th kusttest_test.Harness, filepath string) {
 	th.WriteF(filepath+"mycrd_schema.json", string(bytes))
 }
 
+func writeTestSchemaYaml(th kusttest_test.Harness, filepath string) {
+	bytes, _ := ioutil.ReadFile("testdata/customschema.yaml")
+	th.WriteF(filepath+"mycrd_schema.yaml", string(bytes))
+}
+
 func writeCustomResource(th kusttest_test.Harness, filepath string) {
 	th.WriteF(filepath, `
 apiVersion: example.com/v1alpha1
@@ -103,6 +108,21 @@ openapi:
 	th.AssertActualEqualsExpected(m, patchedCustomResource)
 }
 
+func TestCustomOpenApiFieldYaml(t *testing.T) {
+	th := kusttest_test.MakeHarness(t)
+	th.WriteK(".", `
+resources:
+- mycrd.yaml
+openapi:
+  path: mycrd_schema.yaml
+`+customSchemaPatch)
+	writeCustomResource(th, "mycrd.yaml")
+	writeTestSchemaYaml(th, "./")
+	openapi.ResetOpenAPI()
+	m := th.Run(".", th.MakeDefaultOptions())
+	th.AssertActualEqualsExpected(m, patchedCustomResource)
+}
+
 // Error if user tries to specify both builtin version
 // and custom schema
 func TestCustomOpenApiFieldBothPathAndVersion(t *testing.T) {

api/krusty/testdata/customschema.yaml

@@ -0,0 +1,75 @@
+definitions:
+  v1alpha1.MyCRD:
+    properties:
+      apiVersion:
+        type: string
+      kind:
+        type: string
+      metadata:
+        type: object
+      spec:
+        properties:
+          template:
+            "$ref": "#/definitions/io.k8s.api.core.v1.PodTemplateSpec"
+        type: object
+      status:
+        properties:
+          success:
+            type: boolean
+        type: object
+    type: object
+    x-kubernetes-group-version-kind:
+      - group: example.com
+        kind: MyCRD
+        version: v1alpha1
+  io.k8s.api.core.v1.PodTemplateSpec:
+    properties:
+      metadata:
+        "$ref": "#/definitions/io.k8s.apimachinery.pkg.apis.meta.v1.ObjectMeta"
+      spec:
+        "$ref": "#/definitions/io.k8s.api.core.v1.PodSpec"
+    type: object
+  io.k8s.apimachinery.pkg.apis.meta.v1.ObjectMeta:
+    properties:
+      name:
+        type: string
+    type: object
+  io.k8s.api.core.v1.PodSpec:
+    properties:
+      containers:
+        items:
+          "$ref": "#/definitions/io.k8s.api.core.v1.Container"
+        type: array
+        x-kubernetes-patch-merge-key: name
+        x-kubernetes-patch-strategy: merge
+    type: object
+  io.k8s.api.core.v1.Container:
+    properties:
+      command:
+        items:
+          type: string
+        type: array
+      image:
+        type: string
+      name:
+        type: string
+      ports:
+        items:
+          "$ref": "#/definitions/io.k8s.api.core.v1.ContainerPort"
+        type: array
+        x-kubernetes-list-map-keys:
+          - containerPort
+          - protocol
+        x-kubernetes-list-type: map
+        x-kubernetes-patch-merge-key: containerPort
+        x-kubernetes-patch-strategy: merge
+    type: object
+  io.k8s.api.core.v1.ContainerPort:
+    properties:
+      containerPort:
+        type: integer
+      name:
+        type: string
+      protocol:
+        type: string
+    type: object

cmd/config/go.sum

@@ -248,4 +248,5 @@ k8s.io/kube-openapi v0.0.0-20210421082810-95288971da7e/go.mod h1:vHXdDvt9+2spS2R
 sigs.k8s.io/kustomize/kyaml v0.11.0 h1:9KhiCPKaVyuPcgOLJXkvytOvjMJLoxpjodiycb4gHsA=
 sigs.k8s.io/kustomize/kyaml v0.11.0/go.mod h1:GNMwjim4Ypgp/MueD3zXHLRJEjz7RvtPae0AwlvEMFM=
 sigs.k8s.io/structured-merge-diff/v4 v4.0.2/go.mod h1:bJZC9H9iH24zzfZ/41RGcq60oK1F7G282QMXDPYydCw=
+sigs.k8s.io/yaml v1.2.0 h1:kr/MCeFWJWTwyaHoR9c8EjH9OumOmoF9YGiZd7lFm/Q=
 sigs.k8s.io/yaml v1.2.0/go.mod h1:yfXDCHCao9+ENCvLSE62v9VSji2MKu5jeNfTrofGhJc=

kustomize/commands/openapi/fetch/fetch.go

@@ -8,26 +8,38 @@ import (
 	"os/exec"
 
 	"github.com/spf13/cobra"
+	"sigs.k8s.io/yaml"
 )
 
+var format string
+
 // NewCmdFetch makes a new fetch command.
 func NewCmdFetch(w io.Writer) *cobra.Command {
-	infoCmd := cobra.Command{
+	fetchCmd := cobra.Command{
 		Use: "fetch",
 		Short: `Fetches the OpenAPI specification from the current kubernetes cluster specified 
 in the user's kubeconfig`,
 		Example: `kustomize openapi fetch`,
-		Run: func(cmd *cobra.Command, args []string) {
-			printSchema(w)
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return printSchema(w)
 		},
 	}
-	return &infoCmd
+	fetchCmd.Flags().StringVar(
+		&format,
+		"format",
+		"json",
+		"Specify format for fetched schema ('json' or 'yaml')")
+	return &fetchCmd
 }
 
-func printSchema(w io.Writer) {
+func printSchema(w io.Writer) error {
+	if format != "json" && format != "yaml" {
+		return fmt.Errorf("format must be either 'json' or 'yaml'")
+	}
+
 	errMsg := `
 Error fetching schema from cluster.
-Please make sure kubectl is installed and its context is set correctly.
+Please make sure kubectl is installed, its context is set correctly, and your cluster is up.
 Installation and setup instructions: https://kubernetes.io/docs/tasks/tools/install-kubectl/`
 
 	command := exec.Command("kubectl", []string{"get", "--raw", "/openapi/v2"}...)
@@ -36,15 +48,25 @@ Installation and setup instructions: https://kubernetes.io/docs/tasks/tools/inst
 	command.Stdout = &stdout
 	command.Stderr = &stderr
 	err := command.Run()
-	if err != nil || stdout.String() == "" {
-		fmt.Fprintln(w, err, stderr.String()+errMsg)
-		return
+	if err != nil {
+		return fmt.Errorf("%w\n%s", err, stderr.String()+errMsg)
+	} else if stdout.String() == "" {
+		return fmt.Errorf(stderr.String() + errMsg)
 	}
 
 	// format and output
 	var jsonSchema map[string]interface{}
 	output := stdout.Bytes()
 	json.Unmarshal(output, &jsonSchema)
 	output, _ = json.MarshalIndent(jsonSchema, "", "  ")
+
+	if format == "yaml" {
+		output, err = yaml.JSONToYAML(output)
+		if err != nil {
+			return err
+		}
+	}
+
 	fmt.Fprintln(w, string(output))
+	return nil
 }

kyaml/go.mod

@@ -19,6 +19,7 @@ require (
 	gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15
 	gopkg.in/yaml.v2 v2.4.0
 	k8s.io/kube-openapi v0.0.0-20210421082810-95288971da7e
+	sigs.k8s.io/yaml v1.2.0
 )
 
 // These can be removed after upgrading golangci-lint (Issue #3663)

kyaml/go.sum

@@ -225,4 +225,5 @@ k8s.io/klog/v2 v2.0.0/go.mod h1:PBfzABfn139FHAV07az/IF9Wp1bkk3vpT2XSJ76fSDE=
 k8s.io/kube-openapi v0.0.0-20210421082810-95288971da7e h1:KLHHjkdQFomZy8+06csTWZ0m1343QqxZhR2LJ1OxCYM=
 k8s.io/kube-openapi v0.0.0-20210421082810-95288971da7e/go.mod h1:vHXdDvt9+2spS2Rx9ql3I8tycm3H9FDfdUoIuKCefvw=
 sigs.k8s.io/structured-merge-diff/v4 v4.0.2/go.mod h1:bJZC9H9iH24zzfZ/41RGcq60oK1F7G282QMXDPYydCw=
+sigs.k8s.io/yaml v1.2.0 h1:kr/MCeFWJWTwyaHoR9c8EjH9OumOmoF9YGiZd7lFm/Q=
 sigs.k8s.io/yaml v1.2.0/go.mod h1:yfXDCHCao9+ENCvLSE62v9VSji2MKu5jeNfTrofGhJc=

kyaml/openapi/openapi.go

@@ -16,6 +16,7 @@ import (
 	"sigs.k8s.io/kustomize/kyaml/openapi/kubernetesapi"
 	"sigs.k8s.io/kustomize/kyaml/openapi/kustomizationapi"
 	"sigs.k8s.io/kustomize/kyaml/yaml"
+	k8syaml "sigs.k8s.io/yaml"
 )
 
 // globalSchema contains global state information about the openapi
@@ -536,7 +537,14 @@ func parseBuiltinSchema(version string) {
 // parse parses and indexes a single json schema
 func parse(b []byte) error {
 	var swagger spec.Swagger
-
+	s := string(b)
+	if len(s) > 0 && s[0] != '{' {
+		var err error
+		b, err = k8syaml.YAMLToJSON(b)
+		if err != nil {
+			return errors.Wrap(err)
+		}
+	}
 	if err := swagger.UnmarshalJSON(b); err != nil {
 		return errors.Wrap(err)
 	}