Introduce kuberc as new flag to customize defaulting and define aliases in kubectl (kubernetes#125230)

Author: ardaguclu

pkg/generated/openapi/zz_generated.openapi.go

@@ -73,6 +73,7 @@ import (
 	cmdutil "k8s.io/kubectl/pkg/cmd/util"
 	"k8s.io/kubectl/pkg/cmd/version"
 	"k8s.io/kubectl/pkg/cmd/wait"
+	"k8s.io/kubectl/pkg/kuberc"
 	utilcomp "k8s.io/kubectl/pkg/util/completion"
 	"k8s.io/kubectl/pkg/util/i18n"
 	"k8s.io/kubectl/pkg/util/templates"
@@ -361,6 +362,11 @@ func NewKubectlCommand(o KubectlOptions) *cobra.Command {
 
 	flags.BoolVar(&warningsAsErrors, "warnings-as-errors", warningsAsErrors, "Treat warnings received from the server as errors and exit with a non-zero exit code")
 
+	pref := kuberc.NewPreferences()
+	if cmdutil.KubeRC.IsEnabled() {
+		pref.AddFlags(flags)
+	}
+
 	kubeConfigFlags := o.ConfigFlags
 	if kubeConfigFlags == nil {
 		kubeConfigFlags = defaultConfigFlags().WithWarningPrinter(o.IOStreams)
@@ -490,6 +496,15 @@ func NewKubectlCommand(o KubectlOptions) *cobra.Command {
 	// Stop warning about normalization of flags. That makes it possible to
 	// add the klog flags later.
 	cmds.SetGlobalNormalizationFunc(cliflag.WordSepNormalizeFunc)
+
+	if cmdutil.KubeRC.IsEnabled() {
+		_, err := pref.Apply(cmds, o.Arguments, o.IOStreams.ErrOut)
+		if err != nil {
+			fmt.Fprintf(o.IOStreams.ErrOut, "error occurred while applying preferences %v\n", err)
+			os.Exit(1)
+		}
+	}
+
 	return cmds
 }
 

staging/src/k8s.io/kubectl/pkg/cmd/cmd.go

@@ -432,6 +432,7 @@ const (
 	PortForwardWebsockets   FeatureGate = "KUBECTL_PORT_FORWARD_WEBSOCKETS"
 	// DebugCustomProfile should be dropped in 1.34
 	DebugCustomProfile FeatureGate = "KUBECTL_DEBUG_CUSTOM_PROFILE"
+	KubeRC             FeatureGate = "KUBECTL_KUBERC"
 )
 
 // IsEnabled returns true iff environment variable is set to true.

staging/src/k8s.io/kubectl/pkg/cmd/util/helpers.go

@@ -0,0 +1,12 @@
+# See the OWNERS docs at https://go.k8s.io/owners
+
+# Disable inheritance as this is an api owners file
+options:
+  no_parent_owners: true
+approvers:
+  - api-approvers
+reviewers:
+  - api-reviewers
+  - sig-cli-reviewers
+labels:
+  - kind/api-change

staging/src/k8s.io/kubectl/pkg/config/OWNERS

@@ -0,0 +1,20 @@
+/*
+Copyright 2024 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.
+*/
+
+// +k8s:deepcopy-gen=package
+// +groupName=kubectl.config.k8s.io
+
+package config // Package config import "k8s.io/kubectl/pkg/config"

staging/src/k8s.io/kubectl/pkg/config/doc.go

@@ -0,0 +1,32 @@
+/*
+Copyright 2024 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 install installs the experimental API group, making it available as
+// an option to all of the API encoding/decoding machinery.
+package install
+
+import (
+	"k8s.io/apimachinery/pkg/runtime"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
+	"k8s.io/kubectl/pkg/config"
+	"k8s.io/kubectl/pkg/config/v1alpha1"
+)
+
+// Install registers the API group and adds types to a scheme
+func Install(scheme *runtime.Scheme) {
+	utilruntime.Must(config.AddToScheme(scheme))
+	utilruntime.Must(v1alpha1.AddToScheme(scheme))
+}