kubectl/pkg/cmd/create/create_namespace.go

/*
Copyright 2015 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 create

import (
	"context"
	"fmt"
	"github.com/spf13/cobra"
	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"

	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/cli-runtime/pkg/resource"
	coreclient "k8s.io/client-go/kubernetes/typed/core/v1"
	"k8s.io/kubectl/pkg/scheme"
	"k8s.io/kubectl/pkg/util"

	"k8s.io/cli-runtime/pkg/genericclioptions"
	cmdutil "k8s.io/kubectl/pkg/cmd/util"
	"k8s.io/kubectl/pkg/util/i18n"
	"k8s.io/kubectl/pkg/util/templates"
)

var (
	namespaceLong = templates.LongDesc(i18n.T(`
		Create a namespace with the specified name.`))

	namespaceExample = templates.Examples(i18n.T(`
	  # Create a new namespace named my-namespace
	  kubectl create namespace my-namespace`))
)

// NamespaceOptions is the options for 'create namespace' sub command
type NamespaceOptions struct {
	// PrintFlags holds options necessary for obtaining a printer
	PrintFlags *genericclioptions.PrintFlags
	// Name of resource being created
	Name string

	DryRunStrategy   cmdutil.DryRunStrategy
	DryRunVerifier   *resource.DryRunVerifier
	CreateAnnotation bool
	FieldManager     string

	Client *coreclient.CoreV1Client

	PrintObj func(obj runtime.Object) error

	genericclioptions.IOStreams
}

// NewNamespaceOptions creates a new *NamespaceOptions with sane defaults
func NewNamespaceOptions(ioStreams genericclioptions.IOStreams) *NamespaceOptions {
	return &NamespaceOptions{
		PrintFlags: genericclioptions.NewPrintFlags("created").WithTypeSetter(scheme.Scheme),
		IOStreams:  ioStreams,
	}
}

// NewCmdCreateNamespace is a macro command to create a new namespace
func NewCmdCreateNamespace(f cmdutil.Factory, ioStreams genericclioptions.IOStreams) *cobra.Command {

	o := NewNamespaceOptions(ioStreams)

	cmd := &cobra.Command{
		Use:                   "namespace NAME [--dry-run=server|client|none]",
		DisableFlagsInUseLine: true,
		Aliases:               []string{"ns"},
		Short:                 i18n.T("Create a namespace with the specified name"),
		Long:                  namespaceLong,
		Example:               namespaceExample,
		Run: func(cmd *cobra.Command, args []string) {
			cmdutil.CheckErr(o.Complete(f, cmd, args))
			cmdutil.CheckErr(o.Validate())
			cmdutil.CheckErr(o.Run())
		},
	}

	o.PrintFlags.AddFlags(cmd)

	cmdutil.AddApplyAnnotationFlags(cmd)
	cmdutil.AddValidateFlags(cmd)
	cmdutil.AddDryRunFlag(cmd)
	cmdutil.AddFieldManagerFlagVar(cmd, &o.FieldManager, "kubectl-create")

	return cmd
}

// Complete completes all the required options
func (o *NamespaceOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, args []string) error {
	name, err := NameFromCommandArgs(cmd, args)
	if err != nil {
		return err
	}

	restConfig, err := f.ToRESTConfig()
	if err != nil {
		return err
	}
	o.Client, err = coreclient.NewForConfig(restConfig)
	if err != nil {
		return err
	}

	o.Name = name
	o.DryRunStrategy, err = cmdutil.GetDryRunStrategy(cmd)
	if err != nil {
		return err
	}
	dynamicClient, err := f.DynamicClient()
	if err != nil {
		return err
	}
	discoveryClient, err := f.ToDiscoveryClient()
	if err != nil {
		return err
	}
	o.DryRunVerifier = resource.NewDryRunVerifier(dynamicClient, discoveryClient)
	o.CreateAnnotation = cmdutil.GetFlagBool(cmd, cmdutil.ApplyAnnotationsFlag)
	cmdutil.PrintFlagsWithDryRunStrategy(o.PrintFlags, o.DryRunStrategy)
	printer, err := o.PrintFlags.ToPrinter()
	if err != nil {
		return err
	}
	o.PrintObj = func(obj runtime.Object) error {
		return printer.PrintObj(obj, o.Out)
	}
	return nil
}

// Run calls the CreateSubcommandOptions.Run in NamespaceOpts instance
func (o *NamespaceOptions) Run() error {
	namespace := o.createNamespace()
	if err := util.CreateOrUpdateAnnotation(o.CreateAnnotation, namespace, scheme.DefaultJSONEncoder()); err != nil {
		return err
	}

	if o.DryRunStrategy != cmdutil.DryRunClient {
		createOptions := metav1.CreateOptions{}
		if o.FieldManager != "" {
			createOptions.FieldManager = o.FieldManager
		}
		if o.DryRunStrategy == cmdutil.DryRunServer {
			if err := o.DryRunVerifier.HasSupport(namespace.GroupVersionKind()); err != nil {
				return err
			}
			createOptions.DryRun = []string{metav1.DryRunAll}
		}
		var err error
		namespace, err = o.Client.Namespaces().Create(context.TODO(), namespace, createOptions)
		if err != nil {
			return err
		}
	}
	return o.PrintObj(namespace)
}

// createNamespace outputs a namespace object using the configured fields
func (o *NamespaceOptions) createNamespace() *corev1.Namespace {
	namespace := &corev1.Namespace{
		TypeMeta:   metav1.TypeMeta{APIVersion: corev1.SchemeGroupVersion.String(), Kind: "Namespace"},
		ObjectMeta: metav1.ObjectMeta{Name: o.Name},
	}
	return namespace
}

// Validate validates required fields are set to support structured generation
func (o *NamespaceOptions) Validate() error {
	if len(o.Name) == 0 {
		return fmt.Errorf("name must be specified")
	}
	return nil
}