From fa88ec2314fe6990632365d5af1bb320c3374019 Mon Sep 17 00:00:00 2001
From: Tamal Saha <tamal@appscode.com>
Date: Sun, 24 Dec 2023 00:32:33 -0800
Subject: [PATCH] Avoid contacting kube apiserver is patch is empty

Signed-off-by: Tamal Saha <tamal@appscode.com>
---
 pkg/client/metadata_client.go     | 10 +++++-----
 pkg/client/options.go             | 13 +++++++++++++
 pkg/client/typed_client.go        | 10 +++++-----
 pkg/client/unstructured_client.go | 10 +++++-----
 4 files changed, 28 insertions(+), 15 deletions(-)

diff --git a/pkg/client/metadata_client.go b/pkg/client/metadata_client.go
index d0c6b8e13a..f73eeac0a3 100644
--- a/pkg/client/metadata_client.go
+++ b/pkg/client/metadata_client.go
@@ -98,14 +98,14 @@ func (mc *metadataClient) Patch(ctx context.Context, obj Object, patch Patch, op
 		return err
 	}
 
+	patchOpts := &PatchOptions{}
+	patchOpts.ApplyOptions(opts)
+
 	data, err := patch.Data(obj)
-	if err != nil {
+	if err != nil || (!patchOpts.SendEmptyPatch && string(data) == "{}") {
 		return err
 	}
 
-	patchOpts := &PatchOptions{}
-	patchOpts.ApplyOptions(opts)
-
 	res, err := resInt.Patch(ctx, metadata.Name, patch.Type(), data, *patchOpts.AsPatchOptions())
 	if err != nil {
 		return err
@@ -189,7 +189,7 @@ func (mc *metadataClient) PatchSubResource(ctx context.Context, obj Object, subR
 	}
 
 	data, err := patch.Data(body)
-	if err != nil {
+	if err != nil || (!patchOpts.SendEmptyPatch && string(data) == "{}") {
 		return err
 	}
 
diff --git a/pkg/client/options.go b/pkg/client/options.go
index 798506f486..5e522f1290 100644
--- a/pkg/client/options.go
+++ b/pkg/client/options.go
@@ -747,6 +747,9 @@ type PatchOptions struct {
 
 	// Raw represents raw PatchOptions, as passed to the API server.
 	Raw *metav1.PatchOptions
+
+	// SendEmptyPatch is going to send empty patch calls to the API server.
+	SendEmptyPatch bool
 }
 
 // ApplyOptions applies the given patch options on these options,
@@ -809,6 +812,16 @@ func (forceOwnership) ApplyToSubResourcePatch(opts *SubResourcePatchOptions) {
 	opts.Force = &definitelyTrue
 }
 
+// SendEmptyPatch sets the "sendEmptyPatch" option to true.
+var SendEmptyPatch = sendEmptyPatch{}
+
+type sendEmptyPatch struct{}
+
+// ApplyToPatch applies this configuration to the given patch options.
+func (sendEmptyPatch) ApplyToPatch(opts *PatchOptions) {
+	opts.SendEmptyPatch = true
+}
+
 // }}}
 
 // {{{ DeleteAllOf Options
diff --git a/pkg/client/typed_client.go b/pkg/client/typed_client.go
index 92afd9a9c2..1347882a7f 100644
--- a/pkg/client/typed_client.go
+++ b/pkg/client/typed_client.go
@@ -114,14 +114,14 @@ func (c *typedClient) Patch(ctx context.Context, obj Object, patch Patch, opts .
 		return err
 	}
 
+	patchOpts := &PatchOptions{}
+	patchOpts.ApplyOptions(opts)
+
 	data, err := patch.Data(obj)
-	if err != nil {
+	if err != nil || (!patchOpts.SendEmptyPatch && string(data) == "{}") {
 		return err
 	}
 
-	patchOpts := &PatchOptions{}
-	patchOpts.ApplyOptions(opts)
-
 	return o.Patch(patch.Type()).
 		NamespaceIfScoped(o.GetNamespace(), o.isNamespaced()).
 		Resource(o.resource()).
@@ -263,7 +263,7 @@ func (c *typedClient) PatchSubResource(ctx context.Context, obj Object, subResou
 	}
 
 	data, err := patch.Data(body)
-	if err != nil {
+	if err != nil || (!patchOpts.SendEmptyPatch && string(data) == "{}") {
 		return err
 	}
 
diff --git a/pkg/client/unstructured_client.go b/pkg/client/unstructured_client.go
index 0d96951780..439ba25fd3 100644
--- a/pkg/client/unstructured_client.go
+++ b/pkg/client/unstructured_client.go
@@ -148,14 +148,14 @@ func (uc *unstructuredClient) Patch(ctx context.Context, obj Object, patch Patch
 		return err
 	}
 
+	patchOpts := &PatchOptions{}
+	patchOpts.ApplyOptions(opts)
+
 	data, err := patch.Data(obj)
-	if err != nil {
+	if err != nil || (!patchOpts.SendEmptyPatch && string(data) == "{}") {
 		return err
 	}
 
-	patchOpts := &PatchOptions{}
-	patchOpts.ApplyOptions(opts)
-
 	return o.Patch(patch.Type()).
 		NamespaceIfScoped(o.GetNamespace(), o.isNamespaced()).
 		Resource(o.resource()).
@@ -342,7 +342,7 @@ func (uc *unstructuredClient) PatchSubResource(ctx context.Context, obj Object,
 	}
 
 	data, err := patch.Data(body)
-	if err != nil {
+	if err != nil || (!patchOpts.SendEmptyPatch && string(data) == "{}") {
 		return err
 	}