attempt at server side apply

Signed-off-by: Troy Connor <troy0820@users.noreply.github.com>

Author: troy0820

pkg/client/client.go

@@ -25,6 +25,7 @@ import (
 
 	"k8s.io/apimachinery/pkg/api/meta"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/apimachinery/pkg/runtime/serializer"
@@ -347,6 +348,21 @@ func (c *client) Patch(ctx context.Context, obj Object, patch Patch, opts ...Pat
 	}
 }
 
+func (c *client) Apply(ctx context.Context, obj Object, fieldOwner string) error {
+	var err error
+	switch obj.(type) {
+	case runtime.Unstructured:
+		return c.Patch(ctx, obj, Apply, ForceOwnership, FieldOwner(fieldOwner))
+	default:
+		u := &unstructured.Unstructured{}
+		u.Object, err = runtime.DefaultUnstructuredConverter.ToUnstructured(obj)
+		if err != nil {
+			return err
+		}
+		return c.Patch(ctx, u, Apply, ForceOwnership, FieldOwner(fieldOwner))
+	}
+}
+
 // Get implements client.Client.
 func (c *client) Get(ctx context.Context, key ObjectKey, obj Object, opts ...GetOption) error {
 	if isUncached, err := c.shouldBypassCache(obj); err != nil {

pkg/client/client_test.go

@@ -795,7 +795,30 @@ U5wwSivyi7vmegHKmblOzNVKA5qPO8zWzqBC
 			})
 		})
 	})
-
+	Describe("Server side apply", func() {
+		Context("with a core k8s object", func() {
+			It("should not error", func() {
+				cl, err := client.New(cfg, client.Options{})
+				Expect(err).NotTo(HaveOccurred())
+				Expect(cl).NotTo(BeNil())
+				cm := &corev1.ConfigMap{
+					TypeMeta: metav1.TypeMeta{
+						APIVersion: "v1",
+						Kind:       "ConfigMap",
+					},
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      "config-map",
+						Namespace: "default",
+					},
+					Data: map[string]string{
+						"key": "value",
+					},
+				}
+				err = cl.Apply(ctx, cm, "test-client")
+				Expect(err).NotTo(HaveOccurred())
+			})
+		})
+	})
 	Describe("SubResourceClient", func() {
 		Context("with structured objects", func() {
 			It("should be able to read the Scale subresource", func() {

pkg/client/dryrun.go

@@ -82,6 +82,10 @@ func (c *dryRunClient) Patch(ctx context.Context, obj Object, patch Patch, opts
 	return c.client.Patch(ctx, obj, patch, append(opts, DryRunAll)...)
 }
 
+func (c *dryRunClient) Apply(ctx context.Context, obj Object, fieldOwner string) error {
+	return c.client.Apply(ctx, obj, fieldOwner)
+}
+
 // Get implements client.Client.
 func (c *dryRunClient) Get(ctx context.Context, key ObjectKey, obj Object, opts ...GetOption) error {
 	return c.client.Get(ctx, key, obj, opts...)

pkg/client/fake/client.go

@@ -801,6 +801,10 @@ func (c *fakeClient) Patch(ctx context.Context, obj client.Object, patch client.
 	return c.patch(obj, patch, opts...)
 }
 
+func (c *fakeClient) Apply(ctx context.Context, obj client.Object, fieldOwner string) error {
+	return c.Patch(ctx, obj, client.Apply, client.ForceOwnership, client.FieldOwner(fieldOwner))
+}
+
 func (c *fakeClient) patch(obj client.Object, patch client.Patch, opts ...client.PatchOption) error {
 	patchOptions := &client.PatchOptions{}
 	patchOptions.ApplyOptions(opts)

pkg/client/interceptor/intercept.go

@@ -19,6 +19,7 @@ type Funcs struct {
 	DeleteAllOf       func(ctx context.Context, client client.WithWatch, obj client.Object, opts ...client.DeleteAllOfOption) error
 	Update            func(ctx context.Context, client client.WithWatch, obj client.Object, opts ...client.UpdateOption) error
 	Patch             func(ctx context.Context, client client.WithWatch, obj client.Object, patch client.Patch, opts ...client.PatchOption) error
+	Apply             func(ctx context.Context, client client.WithWatch, obj client.Object, fieldOwner string) error
 	Watch             func(ctx context.Context, client client.WithWatch, obj client.ObjectList, opts ...client.ListOption) (watch.Interface, error)
 	SubResource       func(client client.WithWatch, subResource string) client.SubResourceClient
 	SubResourceGet    func(ctx context.Context, client client.Client, subResourceName string, obj client.Object, subResource client.Object, opts ...client.SubResourceGetOption) error
@@ -92,6 +93,13 @@ func (c interceptor) Patch(ctx context.Context, obj client.Object, patch client.
 	return c.client.Patch(ctx, obj, patch, opts...)
 }
 
+func (c interceptor) Apply(ctx context.Context, obj client.Object, fieldOwner string) error {
+	if c.funcs.Patch != nil {
+		return c.funcs.Apply(ctx, c.client, obj, fieldOwner)
+	}
+	return c.client.Apply(ctx, obj, fieldOwner)
+}
+
 func (c interceptor) DeleteAllOf(ctx context.Context, obj client.Object, opts ...client.DeleteAllOfOption) error {
 	if c.funcs.DeleteAllOf != nil {
 		return c.funcs.DeleteAllOf(ctx, c.client, obj, opts...)

pkg/client/interceptor/intercept_test.go

@@ -360,6 +360,10 @@ func (d dummyClient) Patch(ctx context.Context, obj client.Object, patch client.
 	return nil
 }
 
+func (d dummyClient) Apply(ctx context.Context, obj client.Object, fieldOwner string) error {
+	return nil
+}
+
 func (d dummyClient) DeleteAllOf(ctx context.Context, obj client.Object, opts ...client.DeleteAllOfOption) error {
 	return nil
 }

pkg/client/interfaces.go

@@ -76,6 +76,11 @@ type Writer interface {
 	// struct pointer so that obj can be updated with the content returned by the Server.
 	Patch(ctx context.Context, obj Object, patch Patch, opts ...PatchOption) error
 
+	// Apply patches the given object in the Kubernetes cluster with a server side
+	// apply.  obj must be a struct pointer so that obj can be updated with the
+	// content returned by the Server
+	Apply(ctx context.Context, obj Object, fieldOwner string) error
+
 	// DeleteAllOf deletes all objects of the given type matching the given options.
 	DeleteAllOf(ctx context.Context, obj Object, opts ...DeleteAllOfOption) error
 }

pkg/client/namespaced_client.go

@@ -147,6 +147,23 @@ func (n *namespacedClient) Patch(ctx context.Context, obj Object, patch Patch, o
 	return n.client.Patch(ctx, obj, patch, opts...)
 }
 
+func (n *namespacedClient) Apply(ctx context.Context, obj Object, fieldOwner string) error {
+	isNamespaceScoped, err := n.IsObjectNamespaced(obj)
+	if err != nil {
+		return fmt.Errorf("error finding the scope of the object: %w", err)
+	}
+
+	objectNamespace := obj.GetNamespace()
+	if objectNamespace != n.namespace && objectNamespace != "" {
+		return fmt.Errorf("namespace %s of the object %s does not match the namespace %s on the client", objectNamespace, obj.GetName(), n.namespace)
+	}
+
+	if isNamespaceScoped && objectNamespace == "" {
+		obj.SetNamespace(n.namespace)
+	}
+	return n.client.Apply(ctx, obj, fieldOwner)
+}
+
 // Get implements client.Client.
 func (n *namespacedClient) Get(ctx context.Context, key ObjectKey, obj Object, opts ...GetOption) error {
 	isNamespaceScoped, err := n.IsObjectNamespaced(obj)

pkg/client/typed_client.go

@@ -20,6 +20,8 @@ import (
 	"context"
 
 	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/apimachinery/pkg/util/json"
 )
 
 var _ Reader = &typedClient{}
@@ -132,6 +134,25 @@ func (c *typedClient) Patch(ctx context.Context, obj Object, patch Patch, opts .
 		Into(obj)
 }
 
+func (c *typedClient) Apply(ctx context.Context, obj Object, fieldOwner string) error {
+	o, err := c.resources.getObjMeta(obj)
+	if err != nil {
+		return err
+	}
+
+	data, err := json.Marshal(o)
+	if err != nil {
+		return err
+	}
+	return o.Patch(types.ApplyPatchType).
+		NamespaceIfScoped(o.GetNamespace(), o.isNamespaced()).
+		Resource(o.resource()).
+		Name(o.GetName()).
+		Body(data).
+		Do(ctx).
+		Into(obj)
+}
+
 // Get implements client.Client.
 func (c *typedClient) Get(ctx context.Context, key ObjectKey, obj Object, opts ...GetOption) error {
 	r, err := c.resources.getResource(obj)

pkg/client/unstructured_client.go

@@ -22,6 +22,8 @@ import (
 	"strings"
 
 	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/apimachinery/pkg/util/json"
 )
 
 var _ Reader = &unstructuredClient{}
@@ -166,6 +168,30 @@ func (uc *unstructuredClient) Patch(ctx context.Context, obj Object, patch Patch
 		Into(obj)
 }
 
+func (uc *unstructuredClient) Apply(ctx context.Context, obj Object, fieldOwner string) error {
+	if _, ok := obj.(runtime.Unstructured); !ok {
+		return fmt.Errorf("unstructured client did not understand object: %T", obj)
+	}
+
+	o, err := uc.resources.getObjMeta(obj)
+	if err != nil {
+		return err
+	}
+
+	data, err := json.Marshal(obj)
+	if err != nil {
+		return err
+	}
+
+	return o.Patch(types.ApplyPatchType).
+		NamespaceIfScoped(o.GetNamespace(), o.isNamespaced()).
+		Resource(o.resource()).
+		Name(o.GetName()).
+		Body(data).
+		Do(ctx).
+		Into(obj)
+}
+
 // Get implements client.Client.
 func (uc *unstructuredClient) Get(ctx context.Context, key ObjectKey, obj Object, opts ...GetOption) error {
 	u, ok := obj.(runtime.Unstructured)