Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Implement port forwarding for windows #75479

Merged
merged 1 commit into from
Jun 1, 2019
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 2 additions & 0 deletions pkg/kubelet/dockershim/BUILD
Original file line number Diff line number Diff line change
Expand Up @@ -21,6 +21,8 @@ go_library(
"docker_stats_unsupported.go",
"docker_stats_windows.go",
"docker_streaming.go",
"docker_streaming_others.go",
"docker_streaming_windows.go",
"exec.go",
"helpers.go",
"helpers_linux.go",
Expand Down
63 changes: 1 addition & 62 deletions pkg/kubelet/dockershim/docker_streaming.go
Original file line number Diff line number Diff line change
Expand Up @@ -22,13 +22,9 @@ import (
"fmt"
"io"
"math"
"os/exec"
"strings"
"time"

dockertypes "github.com/docker/docker/api/types"
"k8s.io/klog"

"k8s.io/client-go/tools/remotecommand"
runtimeapi "k8s.io/kubernetes/pkg/kubelet/apis/cri/runtime/v1alpha2"
kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
Expand Down Expand Up @@ -72,7 +68,7 @@ func (r *streamingRuntime) PortForward(podSandboxID string, port int32, stream i
if port < 0 || port > math.MaxUint16 {
return fmt.Errorf("invalid port %d", port)
}
return portForward(r.client, podSandboxID, port, stream)
return r.portForward(podSandboxID, port, stream)
}

// ExecSync executes a command in the container, and returns the stdout output.
Expand Down Expand Up @@ -174,60 +170,3 @@ func attachContainer(client libdocker.Interface, containerID string, stdin io.Re
}
return client.AttachToContainer(containerID, opts, sopts)
}

func portForward(client libdocker.Interface, podSandboxID string, port int32, stream io.ReadWriteCloser) error {
container, err := client.InspectContainer(podSandboxID)
if err != nil {
return err
}

if !container.State.Running {
return fmt.Errorf("container not running (%s)", container.ID)
}

containerPid := container.State.Pid
socatPath, lookupErr := exec.LookPath("socat")
if lookupErr != nil {
return fmt.Errorf("unable to do port forwarding: socat not found.")
}

args := []string{"-t", fmt.Sprintf("%d", containerPid), "-n", socatPath, "-", fmt.Sprintf("TCP4:localhost:%d", port)}

nsenterPath, lookupErr := exec.LookPath("nsenter")
if lookupErr != nil {
return fmt.Errorf("unable to do port forwarding: nsenter not found.")
}

commandString := fmt.Sprintf("%s %s", nsenterPath, strings.Join(args, " "))
klog.V(4).Infof("executing port forwarding command: %s", commandString)

command := exec.Command(nsenterPath, args...)
command.Stdout = stream

stderr := new(bytes.Buffer)
command.Stderr = stderr

// If we use Stdin, command.Run() won't return until the goroutine that's copying
// from stream finishes. Unfortunately, if you have a client like telnet connected
// via port forwarding, as long as the user's telnet client is connected to the user's
// local listener that port forwarding sets up, the telnet session never exits. This
// means that even if socat has finished running, command.Run() won't ever return
// (because the client still has the connection and stream open).
//
// The work around is to use StdinPipe(), as Wait() (called by Run()) closes the pipe
// when the command (socat) exits.
inPipe, err := command.StdinPipe()
if err != nil {
return fmt.Errorf("unable to do port forwarding: error creating stdin pipe: %v", err)
}
go func() {
io.Copy(inPipe, stream)
inPipe.Close()
}()

if err := command.Run(); err != nil {
return fmt.Errorf("%v: %s", err, stderr.String())
}

return nil
}
86 changes: 86 additions & 0 deletions pkg/kubelet/dockershim/docker_streaming_others.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,86 @@
// +build !windows

/*
Copyright 2019 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 dockershim

import (
"bytes"
"fmt"
"io"
"os/exec"
"strings"

"k8s.io/klog"
)

func (r *streamingRuntime) portForward(podSandboxID string, port int32, stream io.ReadWriteCloser) error {
container, err := r.client.InspectContainer(podSandboxID)
if err != nil {
return err
}

if !container.State.Running {
return fmt.Errorf("container not running (%s)", container.ID)
}

containerPid := container.State.Pid
socatPath, lookupErr := exec.LookPath("socat")
if lookupErr != nil {
return fmt.Errorf("unable to do port forwarding: socat not found.")
}

args := []string{"-t", fmt.Sprintf("%d", containerPid), "-n", socatPath, "-", fmt.Sprintf("TCP4:localhost:%d", port)}

nsenterPath, lookupErr := exec.LookPath("nsenter")
if lookupErr != nil {
return fmt.Errorf("unable to do port forwarding: nsenter not found.")
}

commandString := fmt.Sprintf("%s %s", nsenterPath, strings.Join(args, " "))
klog.V(4).Infof("executing port forwarding command: %s", commandString)

command := exec.Command(nsenterPath, args...)
command.Stdout = stream

stderr := new(bytes.Buffer)
command.Stderr = stderr

// If we use Stdin, command.Run() won't return until the goroutine that's copying
// from stream finishes. Unfortunately, if you have a client like telnet connected
// via port forwarding, as long as the user's telnet client is connected to the user's
// local listener that port forwarding sets up, the telnet session never exits. This
// means that even if socat has finished running, command.Run() won't ever return
// (because the client still has the connection and stream open).
//
// The work around is to use StdinPipe(), as Wait() (called by Run()) closes the pipe
// when the command (socat) exits.
inPipe, err := command.StdinPipe()
if err != nil {
return fmt.Errorf("unable to do port forwarding: error creating stdin pipe: %v", err)
}
go func() {
io.Copy(inPipe, stream)
inPipe.Close()
}()

if err := command.Run(); err != nil {
return fmt.Errorf("%v: %s", err, stderr.String())
}

return nil
}
37 changes: 37 additions & 0 deletions pkg/kubelet/dockershim/docker_streaming_windows.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,37 @@
// +build windows

/*
Copyright 2019 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 dockershim

import (
"bytes"
"fmt"
"io"

"k8s.io/kubernetes/pkg/kubelet/util/ioutils"
)

func (r *streamingRuntime) portForward(podSandboxID string, port int32, stream io.ReadWriteCloser) error {
stderr := new(bytes.Buffer)
err := r.exec(podSandboxID, []string{"wincat.exe", "localhost", fmt.Sprint(port)}, stream, stream, ioutils.WriteCloserWrapper(stderr), false, nil, 0)
if err != nil {
return fmt.Errorf("%v: %s", err, stderr.String())
}

return nil
}