k3s/pkg/kubectl/cmd/run.go

/*
Copyright 2014 The Kubernetes Authors All rights reserved.

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 cmd

import (
	"fmt"
	"io"
	"os"
	"time"

	"github.com/spf13/cobra"
	"k8s.io/kubernetes/pkg/api"
	"k8s.io/kubernetes/pkg/client"
	"k8s.io/kubernetes/pkg/fields"
	"k8s.io/kubernetes/pkg/kubectl"
	cmdutil "k8s.io/kubernetes/pkg/kubectl/cmd/util"
	"k8s.io/kubernetes/pkg/labels"
)

const (
	run_long = `Create and run a particular image, possibly replicated.
Creates a replication controller to manage the created container(s).`
	run_example = `// Starts a single instance of nginx.
$ kubectl run nginx --image=nginx

// Starts a replicated instance of nginx.
$ kubectl run nginx --image=nginx --replicas=5

// Dry run. Print the corresponding API objects without creating them.
$ kubectl run nginx --image=nginx --dry-run

// Start a single instance of nginx, but overload the spec of the replication controller with a partial set of values parsed from JSON.
$ kubectl run nginx --image=nginx --overrides='{ "apiVersion": "v1", "spec": { ... } }'`
)

func NewCmdRun(f *cmdutil.Factory, cmdIn io.Reader, cmdOut, cmdErr io.Writer) *cobra.Command {
	cmd := &cobra.Command{
		Use: "run NAME --image=image [--port=port] [--replicas=replicas] [--dry-run=bool] [--overrides=inline-json]",
		// run-container is deprecated
		Aliases: []string{"run-container"},
		Short:   "Run a particular image on the cluster.",
		Long:    run_long,
		Example: run_example,
		Run: func(cmd *cobra.Command, args []string) {
			err := Run(f, cmdIn, cmdOut, cmdErr, cmd, args)
			cmdutil.CheckErr(err)
		},
	}
	cmdutil.AddPrinterFlags(cmd)
	cmd.Flags().String("generator", "run/v1", "The name of the API generator to use.  Default is 'run-controller/v1'.")
	cmd.Flags().String("image", "", "The image for the container to run.")
	cmd.MarkFlagRequired("image")
	cmd.Flags().IntP("replicas", "r", 1, "Number of replicas to create for this container. Default is 1.")
	cmd.Flags().Bool("dry-run", false, "If true, only print the object that would be sent, without sending it.")
	cmd.Flags().String("overrides", "", "An inline JSON override for the generated object. If this is non-empty, it is used to override the generated object. Requires that the object supply a valid apiVersion field.")
	cmd.Flags().Int("port", -1, "The port that this container exposes.")
	cmd.Flags().Int("hostport", -1, "The host port mapping for the container port. To demonstrate a single-machine container.")
	cmd.Flags().StringP("labels", "l", "", "Labels to apply to the pod(s).")
	cmd.Flags().BoolP("stdin", "i", false, "Keep stdin open on the container(s) in the pod, even if nothing is attached.")
	cmd.Flags().Bool("tty", false, "Allocated a TTY for each container in the pod.  Because -t is currently shorthand for --template, -t is not supported for --tty. This shorthand is deprecated and we expect to adopt -t for --tty soon.")
	cmd.Flags().Bool("attach", false, "If true, wait for the Pod to start running, and then attach to the Pod as if 'kubectl attach ...' were called.  Default false, unless '-i/--interactive' is set, in which case the default is true.")
	return cmd
}

func Run(f *cmdutil.Factory, cmdIn io.Reader, cmdOut, cmdErr io.Writer, cmd *cobra.Command, args []string) error {
	if len(os.Args) > 1 && os.Args[1] == "run-container" {
		printDeprecationWarning("run", "run-container")
	}

	if len(args) != 1 {
		return cmdutil.UsageError(cmd, "NAME is required for run")
	}

	interactive := cmdutil.GetFlagBool(cmd, "stdin")
	tty := cmdutil.GetFlagBool(cmd, "tty")
	if tty && !interactive {
		return cmdutil.UsageError(cmd, "-i/--stdin is required for containers with --tty=true")
	}
	replicas := cmdutil.GetFlagInt(cmd, "replicas")
	if interactive && replicas != 1 {
		return cmdutil.UsageError(cmd, fmt.Sprintf("-i/--stdin requires that replicas is 1, found %d", replicas))
	}

	namespace, _, err := f.DefaultNamespace()
	if err != nil {
		return err
	}

	client, err := f.Client()
	if err != nil {
		return err
	}

	generatorName := cmdutil.GetFlagString(cmd, "generator")
	generator, found := f.Generator(generatorName)
	if !found {
		return cmdutil.UsageError(cmd, fmt.Sprintf("Generator: %s not found.", generator))
	}
	names := generator.ParamNames()
	params := kubectl.MakeParams(cmd, names)
	params["name"] = args[0]

	err = kubectl.ValidateParams(names, params)
	if err != nil {
		return err
	}

	controller, err := generator.Generate(params)
	if err != nil {
		return err
	}

	inline := cmdutil.GetFlagString(cmd, "overrides")
	if len(inline) > 0 {
		controller, err = cmdutil.Merge(controller, inline, "ReplicationController")
		if err != nil {
			return err
		}
	}

	// TODO: extract this flag to a central location, when such a location exists.
	if !cmdutil.GetFlagBool(cmd, "dry-run") {
		controller, err = client.ReplicationControllers(namespace).Create(controller.(*api.ReplicationController))
		if err != nil {
			return err
		}
	}

	attachFlag := cmd.Flags().Lookup("attach")
	attach := cmdutil.GetFlagBool(cmd, "attach")

	if !attachFlag.Changed && interactive {
		attach = true
	}

	if attach {
		opts := &AttachOptions{
			In:    cmdIn,
			Out:   cmdOut,
			Err:   cmdErr,
			Stdin: interactive,
			TTY:   tty,

			Attach: &DefaultRemoteAttach{},
		}
		config, err := f.ClientConfig()
		if err != nil {
			return err
		}
		opts.Config = config

		client, err := f.Client()
		if err != nil {
			return err
		}
		opts.Client = client
		return handleAttach(client, controller.(*api.ReplicationController), opts)
	}
	return f.PrintObject(cmd, controller, cmdOut)
}

func waitForPodRunning(c *client.Client, pod *api.Pod, out io.Writer) error {
	for {
		pod, err := c.Pods(pod.Namespace).Get(pod.Name)
		if err != nil {
			return err
		}
		if pod.Status.Phase == api.PodRunning {
			ready := true
			for _, status := range pod.Status.ContainerStatuses {
				if !status.Ready {
					ready = false
					break
				}
			}
			if ready {
				return nil
			}
		}
		fmt.Fprintf(out, "Waiting for pod %s/%s to be running\n", pod.Namespace, pod.Name)
		time.Sleep(2 * time.Second)
		continue
	}
}

func handleAttach(c *client.Client, controller *api.ReplicationController, opts *AttachOptions) error {
	var pods *api.PodList
	for pods == nil || len(pods.Items) == 0 {
		var err error
		if pods, err = c.Pods(controller.Namespace).List(labels.SelectorFromSet(controller.Spec.Selector), fields.Everything()); err != nil {
			return err
		}
		if len(pods.Items) == 0 {
			fmt.Fprint(opts.Out, "Waiting for pod to be scheduled\n")
			time.Sleep(2 * time.Second)
		}
	}
	pod := &pods.Items[0]

	if err := waitForPodRunning(c, pod, opts.Out); err != nil {
		return err
	}
	opts.Client = c
	opts.PodName = pod.Name
	opts.Namespace = pod.Namespace
	return opts.Run()
}