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Don't use command pipes for exec/port forward

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Switch to passing the streams for Stdin/Stdout/Stderr instead of using
StdinPipe() etc because the pipes are incompatible with Run()/Wait().
This commit is contained in:
Andy Goldstein 2015-04-07 10:15:51 -04:00
parent 24b478dd0a
commit 4c1cba5312
1 changed files with 18 additions and 37 deletions
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55
pkg/kubelet/dockertools/docker.go
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@ -220,6 +220,11 @@ func (d *dockerContainerCommandRunner) RunInContainer(containerID string, cmd []
// - should we support nsenter in a container, running with elevated privs and --pid=host?
// - use strong type for containerId
func (d *dockerContainerCommandRunner) ExecInContainer(containerId string, cmd []string, stdin io.Reader, stdout, stderr io.WriteCloser, tty bool) error {
nsenter, err := exec.LookPath("nsenter")
if err != nil {
return fmt.Errorf("exec unavailable - unable to locate nsenter")
}
container, err := d.client.InspectContainer(containerId)
if err != nil {
return err
@ -236,8 +241,7 @@ func (d *dockerContainerCommandRunner) ExecInContainer(containerId string, cmd [
args = append(args, fmt.Sprintf("HOSTNAME=%s", container.Config.Hostname))
args = append(args, container.Config.Env...)
args = append(args, cmd...)
command := exec.Command("nsenter", args...)
// TODO use exec.LookPath
command := exec.Command(nsenter, args...)
if tty {
p, err := StartPty(command)
if err != nil {
@ -258,39 +262,24 @@ func (d *dockerContainerCommandRunner) ExecInContainer(containerId string, cmd [
return command.Wait()
} else {
cp := func(dst io.WriteCloser, src io.Reader, closeDst bool) {
defer func() {
if closeDst {
dst.Close()
}
}()
io.Copy(dst, src)
}
if stdin != nil {
inPipe, err := command.StdinPipe()
// Use an os.Pipe here as it returns true *os.File objects.
// This way, if you run 'kubectl exec -p <pod> -i bash' (no tty) and type 'exit',
// the call below to command.Run() can unblock because its Stdin is the read half
// of the pipe.
r, w, err := os.Pipe()
if err != nil {
return err
}
go func() {
cp(inPipe, stdin, false)
inPipe.Close()
}()
}
go io.Copy(w, stdin)
command.Stdin = r
}
if stdout != nil {
outPipe, err := command.StdoutPipe()
if err != nil {
return err
}
go cp(stdout, outPipe, true)
command.Stdout = stdout
}
if stderr != nil {
errPipe, err := command.StderrPipe()
if err != nil {
return err
}
go cp(stderr, errPipe, true)
command.Stderr = stderr
}
return command.Run()
@ -324,16 +313,8 @@ func (d *dockerContainerCommandRunner) PortForward(pod *kubecontainer.Pod, port
args := []string{"-t", fmt.Sprintf("%d", containerPid), "-n", "socat", "-", fmt.Sprintf("TCP4:localhost:%d", port)}
// TODO use exec.LookPath
command := exec.Command("nsenter", args...)
in, err := command.StdinPipe()
if err != nil {
return err
}
out, err := command.StdoutPipe()
if err != nil {
return err
}
go io.Copy(in, stream)
go io.Copy(stream, out)
command.Stdin = stream
command.Stdout = stream
return command.Run()
}