This commit adds a namespace enforcing wrapper for client.Client.

This helps while dealing with namespace-scoped objects, where the
namespace value need not be specified in every operation.

Author: varshaprasad96

pkg/client/namespaced_client.go

@@ -0,0 +1,156 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package client
+
+import (
+	"context"
+
+	"k8s.io/apimachinery/pkg/api/meta"
+	"k8s.io/apimachinery/pkg/runtime"
+)
+
+// NewNamespacedClient wraps an existing client enforcing the namespace value.
+// All functions using this client will have the same namespace declared here.
+func NewNamespacedClient(c Client, ns string) Client {
+	return &namespacedClient{
+		client:    c,
+		namespace: ns,
+	}
+}
+
+var _ Client = &namespacedClient{}
+
+// namespacedClient is a Client that wraps another Client in order to enforce the specified namespace value.
+type namespacedClient struct {
+	namespace string
+	client    Client
+}
+
+// Create implements clinet.Client
+func (n *namespacedClient) Create(ctx context.Context, obj runtime.Object, opts ...CreateOption) error {
+	metaObj, err := meta.Accessor(obj)
+	if err != nil {
+		return err
+	}
+
+	if n.namespace != "" && metaObj.GetNamespace() != n.namespace {
+		metaObj.SetNamespace(n.namespace)
+	}
+	return n.client.Create(ctx, obj, opts...)
+}
+
+// Update implements client.Client
+func (n *namespacedClient) Update(ctx context.Context, obj runtime.Object, opts ...UpdateOption) error {
+	metaObj, err := meta.Accessor(obj)
+	if err != nil {
+		return err
+	}
+
+	if n.namespace != "" && metaObj.GetNamespace() != n.namespace {
+		metaObj.SetNamespace(n.namespace)
+	}
+	return n.client.Update(ctx, obj, opts...)
+}
+
+// Delete implements client.Client
+func (n *namespacedClient) Delete(ctx context.Context, obj runtime.Object, opts ...DeleteOption) error {
+	metaObj, err := meta.Accessor(obj)
+	if err != nil {
+		return err
+	}
+
+	if n.namespace != "" && metaObj.GetNamespace() != n.namespace {
+		metaObj.SetNamespace(n.namespace)
+	}
+	return n.client.Delete(ctx, obj, opts...)
+}
+
+// DeleteAllOf implements client.Client
+func (n *namespacedClient) DeleteAllOf(ctx context.Context, obj runtime.Object, opts ...DeleteAllOfOption) error {
+	if n.namespace != "" {
+		opts = append(opts, InNamespace(n.namespace))
+	}
+	return n.client.DeleteAllOf(ctx, obj, opts...)
+}
+
+// Patch implements client.Client
+func (n *namespacedClient) Patch(ctx context.Context, obj runtime.Object, patch Patch, opts ...PatchOption) error {
+	metaObj, err := meta.Accessor(obj)
+	if err != nil {
+		return err
+	}
+
+	if n.namespace != "" && metaObj.GetNamespace() != n.namespace {
+		metaObj.SetNamespace(n.namespace)
+	}
+	return n.client.Patch(ctx, obj, patch, opts...)
+}
+
+// Get implements client.Client
+func (n *namespacedClient) Get(ctx context.Context, key ObjectKey, obj runtime.Object) error {
+	if n.namespace != "" {
+		key.Namespace = n.namespace
+	}
+	return n.client.Get(ctx, key, obj)
+}
+
+// List implements client.Client
+func (n *namespacedClient) List(ctx context.Context, obj runtime.Object, opts ...ListOption) error {
+	if n.namespace != "" {
+		opts = append(opts, InNamespace(n.namespace))
+	}
+	return n.client.List(ctx, obj, opts...)
+}
+
+// Status implements client.StatusClient
+func (n *namespacedClient) Status() StatusWriter {
+	return &namespacedClientStatusWriter{client: n.client.Status(), namespace: n.namespace}
+}
+
+// ensure namespacedClientStatusWriter implements client.StatusWriter
+var _ StatusWriter = &namespacedClientStatusWriter{}
+
+type namespacedClientStatusWriter struct {
+	client    StatusWriter
+	namespace string
+}
+
+// Update implements client.StatusWriter
+func (nsw *namespacedClientStatusWriter) Update(ctx context.Context, obj runtime.Object, opts ...UpdateOption) error {
+	metaObj, err := meta.Accessor(obj)
+	if err != nil {
+		return err
+	}
+
+	if nsw.namespace != "" && metaObj.GetNamespace() != nsw.namespace {
+		metaObj.SetNamespace(nsw.namespace)
+	}
+	return nsw.client.Update(ctx, obj, opts...)
+}
+
+// Patch implements client.StatusWriter
+func (nsw *namespacedClientStatusWriter) Patch(ctx context.Context, obj runtime.Object, patch Patch, opts ...PatchOption) error {
+	metaObj, err := meta.Accessor(obj)
+	if err != nil {
+		return err
+	}
+
+	if nsw.namespace != "" && metaObj.GetNamespace() != nsw.namespace {
+		metaObj.SetNamespace(nsw.namespace)
+	}
+	return nsw.client.Patch(ctx, obj, patch, opts...)
+}