⚠️ Add Server-Side DryRun support to Client

hack/check-everything.sh

@@ -19,7 +19,7 @@ set -e
 hack_dir=$(dirname ${BASH_SOURCE})
 source ${hack_dir}/common.sh
 
-k8s_version=1.10.1
+k8s_version=1.13.1
 goarch=amd64
 goos="unknown"
 

pkg/client/client.go

@@ -104,21 +104,21 @@ type client struct {
 }
 
 // Create implements client.Client
-func (c *client) Create(ctx context.Context, obj runtime.Object) error {
+func (c *client) Create(ctx context.Context, obj runtime.Object, opts ...CreateOptionFunc) error {
 	_, ok := obj.(*unstructured.Unstructured)
 	if ok {
-		return c.unstructuredClient.Create(ctx, obj)
+		return c.unstructuredClient.Create(ctx, obj, opts...)
 	}
-	return c.typedClient.Create(ctx, obj)
+	return c.typedClient.Create(ctx, obj, opts...)
 }
 
 // Update implements client.Client
-func (c *client) Update(ctx context.Context, obj runtime.Object) error {
+func (c *client) Update(ctx context.Context, obj runtime.Object, opts ...UpdateOptionFunc) error {
 	_, ok := obj.(*unstructured.Unstructured)
 	if ok {
-		return c.unstructuredClient.Update(ctx, obj)
+		return c.unstructuredClient.Update(ctx, obj, opts...)
 	}
-	return c.typedClient.Update(ctx, obj)
+	return c.typedClient.Update(ctx, obj, opts...)
 }
 
 // Delete implements client.Client

pkg/client/client_test.go

@@ -255,6 +255,25 @@ var _ = Describe("Client", func() {
 				// TODO(seans3): implement these
 				// Example: ListOptions
 			})
+
+			Context("with the DryRun option", func() {
+				It("should not create a new object", func(done Done) {
+					cl, err := client.New(cfg, client.Options{})
+					Expect(err).NotTo(HaveOccurred())
+					Expect(cl).NotTo(BeNil())
+
+					By("creating the object (with DryRun)")
+					err = cl.Create(context.TODO(), dep, client.CreateDryRunAll())
+					Expect(err).NotTo(HaveOccurred())
+
+					actual, err := clientset.AppsV1().Deployments(ns).Get(dep.Name, metav1.GetOptions{})
+					Expect(err).To(HaveOccurred())
+					Expect(errors.IsNotFound(err)).To(BeTrue())
+					Expect(actual).To(Equal(&appsv1.Deployment{}))
+
+					close(done)
+				})
+			})
 		})
 
 		Context("with unstructured objects", func() {
@@ -367,6 +386,33 @@ var _ = Describe("Client", func() {
 
 		})
 
+		Context("with the DryRun option", func() {
+			It("should not create a new object from a go struct", func(done Done) {
+				cl, err := client.New(cfg, client.Options{})
+				Expect(err).NotTo(HaveOccurred())
+				Expect(cl).NotTo(BeNil())
+
+				By("encoding the deployment as unstructured")
+				u := &unstructured.Unstructured{}
+				scheme.Convert(dep, u, nil)
+				u.SetGroupVersionKind(schema.GroupVersionKind{
+					Group:   "apps",
+					Kind:    "Deployment",
+					Version: "v1",
+				})
+
+				By("creating the object")
+				err = cl.Create(context.TODO(), u, client.CreateDryRunAll())
+				Expect(err).NotTo(HaveOccurred())
+
+				actual, err := clientset.AppsV1().Deployments(ns).Get(dep.Name, metav1.GetOptions{})
+				Expect(err).To(HaveOccurred())
+				Expect(errors.IsNotFound(err)).To(BeTrue())
+				Expect(actual).To(Equal(&appsv1.Deployment{}))
+
+				close(done)
+			})
+		})
 	})
 
 	Describe("Update", func() {
@@ -1722,6 +1768,22 @@ var _ = Describe("Client", func() {
 		})
 	})
 
+	Describe("CreateOptions", func() {
+		It("should allow setting DryRun to 'all'", func() {
+			co := &client.CreateOptions{}
+			client.CreateDryRunAll()(co)
+			all := []string{metav1.DryRunAll}
+			Expect(co.AsCreateOptions().DryRun).To(Equal(all))
+		})
+
+		It("should produce empty metav1.CreateOptions if nil", func() {
+			var co *client.CreateOptions
+			Expect(co.AsCreateOptions()).To(Equal(&metav1.CreateOptions{}))
+			co = &client.CreateOptions{}
+			Expect(co.AsCreateOptions()).To(Equal(&metav1.CreateOptions{}))
+		})
+	})
+
 	Describe("DeleteOptions", func() {
 		It("should allow setting GracePeriodSeconds", func() {
 			do := &client.DeleteOptions{}
@@ -1846,6 +1908,22 @@ var _ = Describe("Client", func() {
 			Expect(lo.Namespace).To(Equal("test"))
 		})
 	})
+
+	Describe("UpdateOptions", func() {
+		It("should allow setting DryRun to 'all'", func() {
+			uo := &client.UpdateOptions{}
+			client.UpdateDryRunAll()(uo)
+			all := []string{metav1.DryRunAll}
+			Expect(uo.AsUpdateOptions().DryRun).To(Equal(all))
+		})
+
+		It("should produce empty metav1.UpdateOptions if nil", func() {
+			var co *client.UpdateOptions
+			Expect(co.AsUpdateOptions()).To(Equal(&metav1.UpdateOptions{}))
+			co = &client.UpdateOptions{}
+			Expect(co.AsUpdateOptions()).To(Equal(&metav1.UpdateOptions{}))
+		})
+	})
 })
 
 var _ = Describe("DelegatingReader", func() {

pkg/client/fake/client.go

@@ -24,6 +24,7 @@ import (
 	"strings"
 
 	"k8s.io/apimachinery/pkg/api/meta"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/client-go/kubernetes/scheme"
@@ -138,7 +139,16 @@ func (c *fakeClient) List(ctx context.Context, obj runtime.Object, opts ...clien
 	return nil
 }
 
-func (c *fakeClient) Create(ctx context.Context, obj runtime.Object) error {
+func (c *fakeClient) Create(ctx context.Context, obj runtime.Object, opts ...client.CreateOptionFunc) error {
+	createOptions := &client.CreateOptions{}
+	createOptions.ApplyOptions(opts)
+
+	for _, dryRunOpt := range createOptions.DryRun {
+		if dryRunOpt == metav1.DryRunAll {
+			return nil
+		}
+	}
+
 	gvr, err := getGVRFromObject(obj, c.scheme)
 	if err != nil {
 		return err
@@ -163,7 +173,16 @@ func (c *fakeClient) Delete(ctx context.Context, obj runtime.Object, opts ...cli
 	return c.tracker.Delete(gvr, accessor.GetNamespace(), accessor.GetName())
 }
 
-func (c *fakeClient) Update(ctx context.Context, obj runtime.Object) error {
+func (c *fakeClient) Update(ctx context.Context, obj runtime.Object, opts ...client.UpdateOptionFunc) error {
+	updateOptions := &client.UpdateOptions{}
+	updateOptions.ApplyOptions(opts)
+
+	for _, dryRunOpt := range updateOptions.DryRun {
+		if dryRunOpt == metav1.DryRunAll {
+			return nil
+		}
+	}
+
 	gvr, err := getGVRFromObject(obj, c.scheme)
 	if err != nil {
 		return err

pkg/client/fake/client_test.go

@@ -22,6 +22,7 @@ import (
 
 	appsv1 "k8s.io/api/apps/v1"
 	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/types"
@@ -154,6 +155,56 @@ var _ = Describe("Fake client", func() {
 			Expect(list.Items).To(HaveLen(1))
 			Expect(list.Items).To(ConsistOf(*dep2))
 		})
+
+		Context("with the DryRun option", func() {
+			It("should not create a new object", func() {
+				By("Creating a new configmap with DryRun")
+				newcm := &corev1.ConfigMap{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      "new-test-cm",
+						Namespace: "ns2",
+					},
+				}
+				err := cl.Create(nil, newcm, client.CreateDryRunAll())
+				Expect(err).To(BeNil())
+
+				By("Getting the new configmap")
+				namespacedName := types.NamespacedName{
+					Name:      "new-test-cm",
+					Namespace: "ns2",
+				}
+				obj := &corev1.ConfigMap{}
+				err = cl.Get(nil, namespacedName, obj)
+				Expect(err).To(HaveOccurred())
+				Expect(errors.IsNotFound(err)).To(BeTrue())
+				Expect(obj).NotTo(Equal(newcm))
+			})
+
+			It("should not Update the object", func() {
+				By("Updating a new configmap with DryRun")
+				newcm := &corev1.ConfigMap{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      "test-cm",
+						Namespace: "ns2",
+					},
+					Data: map[string]string{
+						"test-key": "new-value",
+					},
+				}
+				err := cl.Update(nil, newcm, client.UpdateDryRunAll())
+				Expect(err).To(BeNil())
+
+				By("Getting the new configmap")
+				namespacedName := types.NamespacedName{
+					Name:      "test-cm",
+					Namespace: "ns2",
+				}
+				obj := &corev1.ConfigMap{}
+				err = cl.Get(nil, namespacedName, obj)
+				Expect(err).To(BeNil())
+				Expect(obj).To(Equal(cm))
+			})
+		})
 	}
 
 	Context("with default scheme.Scheme", func() {

pkg/client/interfaces.go

@@ -57,14 +57,14 @@ type Reader interface {
 // Writer knows how to create, delete, and update Kubernetes objects.
 type Writer interface {
 	// Create saves the object obj in the Kubernetes cluster.
-	Create(ctx context.Context, obj runtime.Object) error
+	Create(ctx context.Context, obj runtime.Object, opts ...CreateOptionFunc) error
 
 	// Delete deletes the given obj from Kubernetes cluster.
 	Delete(ctx context.Context, obj runtime.Object, opts ...DeleteOptionFunc) error
 
 	// Update updates the given obj in the Kubernetes cluster. obj must be a
 	// struct pointer so that obj can be updated with the content returned by the Server.
-	Update(ctx context.Context, obj runtime.Object) error
+	Update(ctx context.Context, obj runtime.Object, opts ...UpdateOptionFunc) error
 }
 
 // StatusClient knows how to create a client which can update status subresource
@@ -106,6 +106,57 @@ type FieldIndexer interface {
 	IndexField(obj runtime.Object, field string, extractValue IndexerFunc) error
 }
 
+// CreateOptions contains options for create requests. It's generally a subset
+// of metav1.CreateOptions.
+type CreateOptions struct {
+	// When present, indicates that modifications should not be
+	// persisted. An invalid or unrecognized dryRun directive will
+	// result in an error response and no further processing of the
+	// request. Valid values are:
+	// - All: all dry run stages will be processed
+	DryRun []string
+
+	// Raw represents raw CreateOptions, as passed to the API server.
+	Raw *metav1.CreateOptions
+}
+
+// AsCreateOptions returns these options as a metav1.CreateOptions.
+// This may mutate the Raw field.
+func (o *CreateOptions) AsCreateOptions() *metav1.CreateOptions {
+
+	if o == nil {
+		return &metav1.CreateOptions{}
+	}
+	if o.Raw == nil {
+		o.Raw = &metav1.CreateOptions{}
+	}
+
+	o.Raw.DryRun = o.DryRun
+	return o.Raw
+}
+
+// ApplyOptions executes the given CreateOptionFuncs and returns the mutated
+// CreateOptions.
+func (o *CreateOptions) ApplyOptions(optFuncs []CreateOptionFunc) *CreateOptions {
+	for _, optFunc := range optFuncs {
+		optFunc(o)
+	}
+	return o
+}
+
+// CreateOptionFunc is a function that mutates a CreateOptions struct. It implements
+// the functional options pattern. See
+// https://github.com/tmrts/go-patterns/blob/master/idiom/functional-options.md.
+type CreateOptionFunc func(*CreateOptions)
+
+// CreateDryRunAll is a functional option that sets the DryRun
+// field of a CreateOptions struct to metav1.DryRunAll.
+func CreateDryRunAll() CreateOptionFunc {
+	return func(opts *CreateOptions) {
+		opts.DryRun = []string{metav1.DryRunAll}
+	}
+}
+
 // DeleteOptions contains options for delete requests. It's generally a subset
 // of metav1.DeleteOptions.
 type DeleteOptions struct {
@@ -326,3 +377,54 @@ func UseListOptions(newOpts *ListOptions) ListOptionFunc {
 		*opts = *newOpts
 	}
 }
+
+// UpdateOptions contains options for create requests. It's generally a subset
+// of metav1.UpdateOptions.
+type UpdateOptions struct {
+	// When present, indicates that modifications should not be
+	// persisted. An invalid or unrecognized dryRun directive will
+	// result in an error response and no further processing of the
+	// request. Valid values are:
+	// - All: all dry run stages will be processed
+	DryRun []string
+
+	// Raw represents raw UpdateOptions, as passed to the API server.
+	Raw *metav1.UpdateOptions
+}
+
+// AsUpdateOptions returns these options as a metav1.UpdateOptions.
+// This may mutate the Raw field.
+func (o *UpdateOptions) AsUpdateOptions() *metav1.UpdateOptions {
+
+	if o == nil {
+		return &metav1.UpdateOptions{}
+	}
+	if o.Raw == nil {
+		o.Raw = &metav1.UpdateOptions{}
+	}
+
+	o.Raw.DryRun = o.DryRun
+	return o.Raw
+}
+
+// ApplyOptions executes the given UpdateOptionFuncs and returns the mutated
+// UpdateOptions.
+func (o *UpdateOptions) ApplyOptions(optFuncs []UpdateOptionFunc) *UpdateOptions {
+	for _, optFunc := range optFuncs {
+		optFunc(o)
+	}
+	return o
+}
+
+// UpdateOptionFunc is a function that mutates a UpdateOptions struct. It implements
+// the functional options pattern. See
+// https://github.com/tmrts/go-patterns/blob/master/idiom/functional-options.md.
+type UpdateOptionFunc func(*UpdateOptions)
+
+// UpdateDryRunAll is a functional option that sets the DryRun
+// field of a UpdateOptions struct to metav1.DryRunAll.
+func UpdateDryRunAll() UpdateOptionFunc {
+	return func(opts *UpdateOptions) {
+		opts.DryRun = []string{metav1.DryRunAll}
+	}
+}