| /* |
| Copyright 2014 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 exec |
| |
| import ( |
| "fmt" |
| "io" |
| "net/url" |
| |
| dockerterm "github.com/docker/docker/pkg/term" |
| "github.com/spf13/cobra" |
| |
| corev1 "k8s.io/api/core/v1" |
| metav1 "k8s.io/apimachinery/pkg/apis/meta/v1" |
| "k8s.io/cli-runtime/pkg/genericclioptions" |
| coreclient "k8s.io/client-go/kubernetes/typed/core/v1" |
| restclient "k8s.io/client-go/rest" |
| "k8s.io/client-go/tools/remotecommand" |
| cmdutil "k8s.io/kubernetes/pkg/kubectl/cmd/util" |
| "k8s.io/kubernetes/pkg/kubectl/scheme" |
| "k8s.io/kubernetes/pkg/kubectl/util/i18n" |
| "k8s.io/kubernetes/pkg/kubectl/util/templates" |
| "k8s.io/kubernetes/pkg/kubectl/util/term" |
| "k8s.io/kubernetes/pkg/util/interrupt" |
| ) |
| |
| var ( |
| exec_example = templates.Examples(i18n.T(` |
| # Get output from running 'date' from pod 123456-7890, using the first container by default |
| kubectl exec 123456-7890 date |
| |
| # Get output from running 'date' in ruby-container from pod 123456-7890 |
| kubectl exec 123456-7890 -c ruby-container date |
| |
| # Switch to raw terminal mode, sends stdin to 'bash' in ruby-container from pod 123456-7890 |
| # and sends stdout/stderr from 'bash' back to the client |
| kubectl exec 123456-7890 -c ruby-container -i -t -- bash -il |
| |
| # List contents of /usr from the first container of pod 123456-7890 and sort by modification time. |
| # If the command you want to execute in the pod has any flags in common (e.g. -i), |
| # you must use two dashes (--) to separate your command's flags/arguments. |
| # Also note, do not surround your command and its flags/arguments with quotes |
| # unless that is how you would execute it normally (i.e., do ls -t /usr, not "ls -t /usr"). |
| kubectl exec 123456-7890 -i -t -- ls -t /usr |
| `)) |
| ) |
| |
| const ( |
| execUsageStr = "expected 'exec POD_NAME COMMAND [ARG1] [ARG2] ... [ARGN]'.\nPOD_NAME and COMMAND are required arguments for the exec command" |
| ) |
| |
| func NewCmdExec(f cmdutil.Factory, streams genericclioptions.IOStreams) *cobra.Command { |
| options := &ExecOptions{ |
| StreamOptions: StreamOptions{ |
| IOStreams: streams, |
| }, |
| |
| Executor: &DefaultRemoteExecutor{}, |
| } |
| cmd := &cobra.Command{ |
| Use: "exec POD [-c CONTAINER] -- COMMAND [args...]", |
| DisableFlagsInUseLine: true, |
| Short: i18n.T("Execute a command in a container"), |
| Long: "Execute a command in a container.", |
| Example: exec_example, |
| Run: func(cmd *cobra.Command, args []string) { |
| argsLenAtDash := cmd.ArgsLenAtDash() |
| cmdutil.CheckErr(options.Complete(f, cmd, args, argsLenAtDash)) |
| cmdutil.CheckErr(options.Validate()) |
| cmdutil.CheckErr(options.Run()) |
| }, |
| } |
| cmd.Flags().StringVarP(&options.PodName, "pod", "p", options.PodName, "Pod name") |
| cmd.Flags().MarkDeprecated("pod", "This flag is deprecated and will be removed in future. Use exec POD_NAME instead.") |
| // TODO support UID |
| cmd.Flags().StringVarP(&options.ContainerName, "container", "c", options.ContainerName, "Container name. If omitted, the first container in the pod will be chosen") |
| cmd.Flags().BoolVarP(&options.Stdin, "stdin", "i", options.Stdin, "Pass stdin to the container") |
| cmd.Flags().BoolVarP(&options.TTY, "tty", "t", options.TTY, "Stdin is a TTY") |
| return cmd |
| } |
| |
| // RemoteExecutor defines the interface accepted by the Exec command - provided for test stubbing |
| type RemoteExecutor interface { |
| Execute(method string, url *url.URL, config *restclient.Config, stdin io.Reader, stdout, stderr io.Writer, tty bool, terminalSizeQueue remotecommand.TerminalSizeQueue) error |
| } |
| |
| // DefaultRemoteExecutor is the standard implementation of remote command execution |
| type DefaultRemoteExecutor struct{} |
| |
| func (*DefaultRemoteExecutor) Execute(method string, url *url.URL, config *restclient.Config, stdin io.Reader, stdout, stderr io.Writer, tty bool, terminalSizeQueue remotecommand.TerminalSizeQueue) error { |
| exec, err := remotecommand.NewSPDYExecutor(config, method, url) |
| if err != nil { |
| return err |
| } |
| return exec.Stream(remotecommand.StreamOptions{ |
| Stdin: stdin, |
| Stdout: stdout, |
| Stderr: stderr, |
| Tty: tty, |
| TerminalSizeQueue: terminalSizeQueue, |
| }) |
| } |
| |
| type StreamOptions struct { |
| Namespace string |
| PodName string |
| ContainerName string |
| Stdin bool |
| TTY bool |
| // minimize unnecessary output |
| Quiet bool |
| // InterruptParent, if set, is used to handle interrupts while attached |
| InterruptParent *interrupt.Handler |
| |
| genericclioptions.IOStreams |
| |
| // for testing |
| overrideStreams func() (io.ReadCloser, io.Writer, io.Writer) |
| isTerminalIn func(t term.TTY) bool |
| } |
| |
| // ExecOptions declare the arguments accepted by the Exec command |
| type ExecOptions struct { |
| StreamOptions |
| |
| Command []string |
| |
| FullCmdName string |
| SuggestedCmdUsage string |
| |
| Executor RemoteExecutor |
| PodClient coreclient.PodsGetter |
| Config *restclient.Config |
| } |
| |
| // Complete verifies command line arguments and loads data from the command environment |
| func (p *ExecOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, argsIn []string, argsLenAtDash int) error { |
| // Let kubectl exec follow rules for `--`, see #13004 issue |
| if len(p.PodName) == 0 && (len(argsIn) == 0 || argsLenAtDash == 0) { |
| return cmdutil.UsageErrorf(cmd, execUsageStr) |
| } |
| if len(p.PodName) != 0 { |
| if len(argsIn) < 1 { |
| return cmdutil.UsageErrorf(cmd, execUsageStr) |
| } |
| p.Command = argsIn |
| } else { |
| p.PodName = argsIn[0] |
| p.Command = argsIn[1:] |
| if len(p.Command) < 1 { |
| return cmdutil.UsageErrorf(cmd, execUsageStr) |
| } |
| } |
| |
| namespace, _, err := f.ToRawKubeConfigLoader().Namespace() |
| if err != nil { |
| return err |
| } |
| p.Namespace = namespace |
| |
| cmdParent := cmd.Parent() |
| if cmdParent != nil { |
| p.FullCmdName = cmdParent.CommandPath() |
| } |
| if len(p.FullCmdName) > 0 && cmdutil.IsSiblingCommandExists(cmd, "describe") { |
| p.SuggestedCmdUsage = fmt.Sprintf("Use '%s describe pod/%s -n %s' to see all of the containers in this pod.", p.FullCmdName, p.PodName, p.Namespace) |
| } |
| |
| config, err := f.ToRESTConfig() |
| if err != nil { |
| return err |
| } |
| p.Config = config |
| |
| clientset, err := f.KubernetesClientSet() |
| if err != nil { |
| return err |
| } |
| p.PodClient = clientset.CoreV1() |
| |
| return nil |
| } |
| |
| // Validate checks that the provided exec options are specified. |
| func (p *ExecOptions) Validate() error { |
| if len(p.PodName) == 0 { |
| return fmt.Errorf("pod name must be specified") |
| } |
| if len(p.Command) == 0 { |
| return fmt.Errorf("you must specify at least one command for the container") |
| } |
| if p.Out == nil || p.ErrOut == nil { |
| return fmt.Errorf("both output and error output must be provided") |
| } |
| if p.Executor == nil || p.PodClient == nil || p.Config == nil { |
| return fmt.Errorf("client, client config, and executor must be provided") |
| } |
| return nil |
| } |
| |
| func (o *StreamOptions) SetupTTY() term.TTY { |
| t := term.TTY{ |
| Parent: o.InterruptParent, |
| Out: o.Out, |
| } |
| |
| if !o.Stdin { |
| // need to nil out o.In to make sure we don't create a stream for stdin |
| o.In = nil |
| o.TTY = false |
| return t |
| } |
| |
| t.In = o.In |
| if !o.TTY { |
| return t |
| } |
| |
| if o.isTerminalIn == nil { |
| o.isTerminalIn = func(tty term.TTY) bool { |
| return tty.IsTerminalIn() |
| } |
| } |
| if !o.isTerminalIn(t) { |
| o.TTY = false |
| |
| if o.ErrOut != nil { |
| fmt.Fprintln(o.ErrOut, "Unable to use a TTY - input is not a terminal or the right kind of file") |
| } |
| |
| return t |
| } |
| |
| // if we get to here, the user wants to attach stdin, wants a TTY, and o.In is a terminal, so we |
| // can safely set t.Raw to true |
| t.Raw = true |
| |
| if o.overrideStreams == nil { |
| // use dockerterm.StdStreams() to get the right I/O handles on Windows |
| o.overrideStreams = dockerterm.StdStreams |
| } |
| stdin, stdout, _ := o.overrideStreams() |
| o.In = stdin |
| t.In = stdin |
| if o.Out != nil { |
| o.Out = stdout |
| t.Out = stdout |
| } |
| |
| return t |
| } |
| |
| // Run executes a validated remote execution against a pod. |
| func (p *ExecOptions) Run() error { |
| pod, err := p.PodClient.Pods(p.Namespace).Get(p.PodName, metav1.GetOptions{}) |
| if err != nil { |
| return err |
| } |
| |
| if pod.Status.Phase == corev1.PodSucceeded || pod.Status.Phase == corev1.PodFailed { |
| return fmt.Errorf("cannot exec into a container in a completed pod; current phase is %s", pod.Status.Phase) |
| } |
| |
| containerName := p.ContainerName |
| if len(containerName) == 0 { |
| if len(pod.Spec.Containers) > 1 { |
| usageString := fmt.Sprintf("Defaulting container name to %s.", pod.Spec.Containers[0].Name) |
| if len(p.SuggestedCmdUsage) > 0 { |
| usageString = fmt.Sprintf("%s\n%s", usageString, p.SuggestedCmdUsage) |
| } |
| fmt.Fprintf(p.ErrOut, "%s\n", usageString) |
| } |
| containerName = pod.Spec.Containers[0].Name |
| } |
| |
| // ensure we can recover the terminal while attached |
| t := p.SetupTTY() |
| |
| var sizeQueue remotecommand.TerminalSizeQueue |
| if t.Raw { |
| // this call spawns a goroutine to monitor/update the terminal size |
| sizeQueue = t.MonitorSize(t.GetSize()) |
| |
| // unset p.Err if it was previously set because both stdout and stderr go over p.Out when tty is |
| // true |
| p.ErrOut = nil |
| } |
| |
| fn := func() error { |
| restClient, err := restclient.RESTClientFor(p.Config) |
| if err != nil { |
| return err |
| } |
| |
| // TODO: consider abstracting into a client invocation or client helper |
| req := restClient.Post(). |
| Resource("pods"). |
| Name(pod.Name). |
| Namespace(pod.Namespace). |
| SubResource("exec"). |
| Param("container", containerName) |
| req.VersionedParams(&corev1.PodExecOptions{ |
| Container: containerName, |
| Command: p.Command, |
| Stdin: p.Stdin, |
| Stdout: p.Out != nil, |
| Stderr: p.ErrOut != nil, |
| TTY: t.Raw, |
| }, scheme.ParameterCodec) |
| |
| return p.Executor.Execute("POST", req.URL(), p.Config, p.In, p.Out, p.ErrOut, t.Raw, sizeQueue) |
| } |
| |
| if err := t.Safe(fn); err != nil { |
| return err |
| } |
| |
| return nil |
| } |