kubectl/pkg/cmd/create/create_deployment.go

/*
Copyright 2016 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"
	"strings"

	"github.com/spf13/cobra"

	appsv1 "k8s.io/api/apps/v1"
	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/runtime"
	utilrand "k8s.io/apimachinery/pkg/util/rand"
	"k8s.io/cli-runtime/pkg/genericclioptions"
	"k8s.io/cli-runtime/pkg/genericiooptions"
	appsv1client "k8s.io/client-go/kubernetes/typed/apps/v1"
	cmdutil "k8s.io/kubectl/pkg/cmd/util"
	"k8s.io/kubectl/pkg/scheme"
	"k8s.io/kubectl/pkg/util"
	"k8s.io/kubectl/pkg/util/i18n"
	"k8s.io/kubectl/pkg/util/templates"
)

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

	deploymentExample = templates.Examples(i18n.T(`
	# Create a deployment named my-dep that runs the busybox image
	kubectl create deployment my-dep --image=busybox

	# Create a deployment with a command
	kubectl create deployment my-dep --image=busybox -- date

	# Create a deployment named my-dep that runs the nginx image with 3 replicas
	kubectl create deployment my-dep --image=nginx --replicas=3

	# Create a deployment named my-dep that runs the busybox image and expose port 5701
	kubectl create deployment my-dep --image=busybox --port=5701

	# Create a deployment named my-dep that runs multiple containers
	kubectl create deployment my-dep --image=busybox:latest --image=ubuntu:latest --image=nginx`))
)

// CreateDeploymentOptions is returned by NewCmdCreateDeployment
type CreateDeploymentOptions struct {
	PrintFlags *genericclioptions.PrintFlags

	PrintObj func(obj runtime.Object) error

	Name             string
	Images           []string
	Port             int32
	Replicas         int32
	Command          []string
	Namespace        string
	EnforceNamespace bool
	FieldManager     string
	CreateAnnotation bool

	Client              appsv1client.AppsV1Interface
	DryRunStrategy      cmdutil.DryRunStrategy
	ValidationDirective string

	genericiooptions.IOStreams
}

// NewCreateDeploymentOptions returns an initialized CreateDeploymentOptions instance
func NewCreateDeploymentOptions(ioStreams genericiooptions.IOStreams) *CreateDeploymentOptions {
	return &CreateDeploymentOptions{
		Port:       -1,
		Replicas:   1,
		PrintFlags: genericclioptions.NewPrintFlags("created").WithTypeSetter(scheme.Scheme),
		IOStreams:  ioStreams,
	}
}

// NewCmdCreateDeployment is a macro command to create a new deployment.
// This command is better known to users as `kubectl create deployment`.
func NewCmdCreateDeployment(f cmdutil.Factory, ioStreams genericiooptions.IOStreams) *cobra.Command {
	o := NewCreateDeploymentOptions(ioStreams)
	cmd := &cobra.Command{
		Use:                   "deployment NAME --image=image -- [COMMAND] [args...]",
		DisableFlagsInUseLine: true,
		Aliases:               []string{"deploy"},
		Short:                 i18n.T("Create a deployment with the specified name"),
		Long:                  deploymentLong,
		Example:               deploymentExample,
		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)
	cmd.Flags().StringSliceVar(&o.Images, "image", o.Images, "Image names to run. A deployment can have multiple images set for multi-container pod.")
	cmd.MarkFlagRequired("image")
	cmd.Flags().Int32Var(&o.Port, "port", o.Port, "The containerPort that this deployment exposes.")
	cmd.Flags().Int32VarP(&o.Replicas, "replicas", "r", o.Replicas, "Number of replicas to create. Default is 1.")
	cmdutil.AddFieldManagerFlagVar(cmd, &o.FieldManager, "kubectl-create")

	return cmd
}

// Complete completes all the options
func (o *CreateDeploymentOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, args []string) error {
	name, err := NameFromCommandArgs(cmd, args)
	if err != nil {
		return err
	}
	o.Name = name
	if len(args) > 1 {
		o.Command = args[1:]
	}

	clientConfig, err := f.ToRESTConfig()
	if err != nil {
		return err
	}
	o.Client, err = appsv1client.NewForConfig(clientConfig)
	if err != nil {
		return err
	}

	o.Namespace, o.EnforceNamespace, err = f.ToRawKubeConfigLoader().Namespace()
	if err != nil {
		return err
	}

	o.CreateAnnotation = cmdutil.GetFlagBool(cmd, cmdutil.ApplyAnnotationsFlag)

	o.DryRunStrategy, err = cmdutil.GetDryRunStrategy(cmd)
	if err != nil {
		return err
	}
	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)
	}

	o.ValidationDirective, err = cmdutil.GetValidationDirective(cmd)
	if err != nil {
		return err
	}

	return nil
}

// Validate makes sure there is no discrepency in provided option values
func (o *CreateDeploymentOptions) Validate() error {
	if len(o.Images) > 1 && len(o.Command) > 0 {
		return fmt.Errorf("cannot specify multiple --image options and command")
	}
	return nil
}

// Run performs the execution of 'create deployment' sub command
func (o *CreateDeploymentOptions) Run() error {
	deploy := o.createDeployment()

	if err := util.CreateOrUpdateAnnotation(o.CreateAnnotation, deploy, scheme.DefaultJSONEncoder()); err != nil {
		return err
	}

	if o.DryRunStrategy != cmdutil.DryRunClient {
		createOptions := metav1.CreateOptions{}
		if o.FieldManager != "" {
			createOptions.FieldManager = o.FieldManager
		}
		createOptions.FieldValidation = o.ValidationDirective
		if o.DryRunStrategy == cmdutil.DryRunServer {
			createOptions.DryRun = []string{metav1.DryRunAll}
		}
		var err error
		deploy, err = o.Client.Deployments(o.Namespace).Create(context.TODO(), deploy, createOptions)
		if err != nil {
			return fmt.Errorf("failed to create deployment: %v", err)
		}
	}

	return o.PrintObj(deploy)
}

func (o *CreateDeploymentOptions) createDeployment() *appsv1.Deployment {
	labels := map[string]string{"app": o.Name}
	selector := metav1.LabelSelector{MatchLabels: labels}
	namespace := ""
	if o.EnforceNamespace {
		namespace = o.Namespace
	}

	deploy := &appsv1.Deployment{
		TypeMeta: metav1.TypeMeta{APIVersion: appsv1.SchemeGroupVersion.String(), Kind: "Deployment"},
		ObjectMeta: metav1.ObjectMeta{
			Name:      o.Name,
			Labels:    labels,
			Namespace: namespace,
		},
		Spec: appsv1.DeploymentSpec{
			Replicas: &o.Replicas,
			Selector: &selector,
			Template: corev1.PodTemplateSpec{
				ObjectMeta: metav1.ObjectMeta{
					Labels: labels,
				},
				Spec: o.buildPodSpec(),
			},
		},
	}

	if o.Port >= 0 && len(deploy.Spec.Template.Spec.Containers) > 0 {
		deploy.Spec.Template.Spec.Containers[0].Ports = []corev1.ContainerPort{{ContainerPort: o.Port}}
	}
	return deploy
}

// buildPodSpec parses the image strings and assemble them into the Containers
// of a PodSpec. This is all you need to create the PodSpec for a deployment.
func (o *CreateDeploymentOptions) buildPodSpec() corev1.PodSpec {
	podSpec := corev1.PodSpec{Containers: []corev1.Container{}}
	for _, imageString := range o.Images {
		// Retain just the image name
		imageSplit := strings.Split(imageString, "/")
		name := imageSplit[len(imageSplit)-1]
		// Remove any tag or hash
		if strings.Contains(name, ":") {
			name = strings.Split(name, ":")[0]
		}
		if strings.Contains(name, "@") {
			name = strings.Split(name, "@")[0]
		}
		name = sanitizeAndUniquify(name)
		podSpec.Containers = append(podSpec.Containers, corev1.Container{
			Name:    name,
			Image:   imageString,
			Command: o.Command,
		})
	}
	return podSpec
}

// sanitizeAndUniquify replaces characters like "." or "_" into "-" to follow DNS1123 rules.
// Then add random suffix to make it uniquified.
func sanitizeAndUniquify(name string) string {
	if strings.ContainsAny(name, "_.") {
		name = strings.Replace(name, "_", "-", -1)
		name = strings.Replace(name, ".", "-", -1)
		name = fmt.Sprintf("%s-%s", name, utilrand.String(5))
	}
	return name
}