✨ Add FieldValidation setting to client.Options (#3393)

* add FieldValidation field to client.Options struct

* improve new field documentation

* Update pkg/client/client.go

Co-authored-by: Alvaro Aleman <[email protected]>

* remove duplicate information in client.Options.FieldValidation documentation

* Update pkg/client/client.go

Co-authored-by: Alvaro Aleman <[email protected]>

---------

Co-authored-by: Alvaro Aleman <[email protected]>

Author: aerfio

pkg/client/client.go

@@ -61,6 +61,16 @@ type Options struct {
 	// This default can be overridden for a specific call by passing a [FieldOwner] option
 	// to the method.
 	FieldOwner string
+
+	// FieldValidation sets the field validation strategy for all mutating operations performed by this client
+	// and subresource clients created from it.
+	// The exception are apply requests which are always strict, regardless of the FieldValidation setting.
+	// Available values for this option can be found in "k8s.io/apimachinery/pkg/apis/meta/v1" package and are:
+	//  - FieldValidationIgnore
+	//  - FieldValidationWarn
+	//  - FieldValidationStrict
+	// For more details, see: https://kubernetes.io/docs/reference/using-api/api-concepts/#field-validation
+	FieldValidation string
 }
 
 // CacheOptions are options for creating a cache-backed client.
@@ -111,6 +121,9 @@ func New(config *rest.Config, options Options) (c Client, err error) {
 	if fo := options.FieldOwner; fo != "" {
 		c = WithFieldOwner(c, fo)
 	}
+	if fv := options.FieldValidation; fv != "" {
+		c = WithFieldValidation(c, FieldValidation(fv))
+	}
 
 	return c, err
 }

pkg/client/client_test.go

@@ -43,6 +43,7 @@ import (
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/apimachinery/pkg/util/rand"
 	appsv1applyconfigurations "k8s.io/client-go/applyconfigurations/apps/v1"
 	autoscaling1applyconfigurations "k8s.io/client-go/applyconfigurations/autoscaling/v1"
 	corev1applyconfigurations "k8s.io/client-go/applyconfigurations/core/v1"
@@ -378,6 +379,52 @@ U5wwSivyi7vmegHKmblOzNVKA5qPO8zWzqBC
 			Expect(actual.ManagedFields).To(HaveLen(1))
 			Expect(actual.ManagedFields[0].Manager).To(Equal("test-owner"))
 		})
+
+		Context("with the FieldValidation option", func() {
+			It("should log warnings with FieldValidation equal to Warn", func(ctx SpecContext) {
+				restCfg := rest.CopyConfig(cfg)
+				var testLog bytes.Buffer
+				restCfg.WarningHandler = rest.NewWarningWriter(&testLog, rest.WarningWriterOptions{})
+
+				warnClient, err := client.New(restCfg, client.Options{FieldValidation: metav1.FieldValidationWarn})
+				Expect(err).NotTo(HaveOccurred())
+				Expect(warnClient).NotTo(BeNil())
+
+				unstrContent, err := runtime.DefaultUnstructuredConverter.ToUnstructured(
+					corev1applyconfigurations.ConfigMap("test-cm-"+rand.String(3), "default").
+						WithData(map[string]string{"foo": "bar"}),
+				)
+				Expect(err).NotTo(HaveOccurred())
+				unstrContent["additionalField"] = "test"
+				cm := &unstructured.Unstructured{Object: unstrContent}
+
+				err = warnClient.Create(ctx, cm)
+				Expect(err).NotTo(HaveOccurred())
+				Expect(testLog.String()).To(ContainSubstring(`Warning: unknown field "additionalField"`))
+
+			})
+			It("should fail write operation if FieldValidation equals Strict", func(ctx SpecContext) {
+				restCfg := rest.CopyConfig(cfg)
+				var testLog bytes.Buffer
+				restCfg.WarningHandler = rest.NewWarningWriter(&testLog, rest.WarningWriterOptions{})
+				strictClient, err := client.New(restCfg, client.Options{FieldValidation: metav1.FieldValidationStrict})
+				Expect(err).NotTo(HaveOccurred())
+
+				unstrContent, err := runtime.DefaultUnstructuredConverter.ToUnstructured(
+					corev1applyconfigurations.ConfigMap("test-cm-"+rand.String(3), "default").
+						WithData(map[string]string{"foo": "bar"}),
+				)
+				Expect(err).NotTo(HaveOccurred())
+				unstrContent["additionalField"] = "test"
+				cm := &unstructured.Unstructured{Object: unstrContent}
+
+				err = strictClient.Create(ctx, cm)
+				Expect(err).To(HaveOccurred())
+				Expect(err).To(MatchError(ContainSubstring("unknown field \"additionalField\"")))
+				Expect(err).To(MatchError(ContainSubstring("strict decoding error")))
+				Expect(testLog.String()).To(BeEmpty())
+			})
+		})
 	})
 
 	Describe("Create", func() {