DockerCLI/command/container/hijack.go

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package container
import (
"io"
"runtime"
"sync"
"github.com/Sirupsen/logrus"
"github.com/docker/docker/api/types"
"github.com/docker/docker/cli/command"
"github.com/docker/docker/pkg/stdcopy"
"golang.org/x/net/context"
)
// holdHijackedConnection handles copying input to and output from streams to the
// connection
func holdHijackedConnection(ctx context.Context, streams command.Streams, tty bool, inputStream io.ReadCloser, outputStream, errorStream io.Writer, resp types.HijackedResponse) error {
var (
err error
restoreOnce sync.Once
)
if inputStream != nil && tty {
if err := setRawTerminal(streams); err != nil {
return err
}
defer func() {
restoreOnce.Do(func() {
restoreTerminal(streams, inputStream)
})
}()
}
receiveStdout := make(chan error, 1)
if outputStream != nil || errorStream != nil {
go func() {
// When TTY is ON, use regular copy
if tty && outputStream != nil {
_, err = io.Copy(outputStream, resp.Reader)
// we should restore the terminal as soon as possible once connection end
// so any following print messages will be in normal type.
if inputStream != nil {
restoreOnce.Do(func() {
restoreTerminal(streams, inputStream)
})
}
} else {
_, err = stdcopy.StdCopy(outputStream, errorStream, resp.Reader)
}
logrus.Debug("[hijack] End of stdout")
receiveStdout <- err
}()
}
stdinDone := make(chan struct{})
go func() {
if inputStream != nil {
io.Copy(resp.Conn, inputStream)
// we should restore the terminal as soon as possible once connection end
// so any following print messages will be in normal type.
if tty {
restoreOnce.Do(func() {
restoreTerminal(streams, inputStream)
})
}
logrus.Debug("[hijack] End of stdin")
}
if err := resp.CloseWrite(); err != nil {
logrus.Debugf("Couldn't send EOF: %s", err)
}
close(stdinDone)
}()
select {
case err := <-receiveStdout:
if err != nil {
logrus.Debugf("Error receiveStdout: %s", err)
return err
}
case <-stdinDone:
if outputStream != nil || errorStream != nil {
select {
case err := <-receiveStdout:
if err != nil {
logrus.Debugf("Error receiveStdout: %s", err)
return err
}
case <-ctx.Done():
}
}
case <-ctx.Done():
}
return nil
}
func setRawTerminal(streams command.Streams) error {
if err := streams.In().SetRawTerminal(); err != nil {
return err
}
return streams.Out().SetRawTerminal()
}
func restoreTerminal(streams command.Streams, in io.Closer) error {
streams.In().RestoreTerminal()
streams.Out().RestoreTerminal()
// WARNING: DO NOT REMOVE THE OS CHECKS !!!
// For some reason this Close call blocks on darwin..
// As the client exits right after, simply discard the close
// until we find a better solution.
//
// This can also cause the client on Windows to get stuck in Win32 CloseHandle()
// in some cases. See https://github.com/docker/docker/issues/28267#issuecomment-288237442
// Tracked internally at Microsoft by VSO #11352156. In the
// Windows case, you hit this if you are using the native/v2 console,
// not the "legacy" console, and you start the client in a new window. eg
// `start docker run --rm -it microsoft/nanoserver cmd /s /c echo foobar`
// will hang. Remove start, and it won't repro.
if in != nil && runtime.GOOS != "darwin" && runtime.GOOS != "windows" {
return in.Close()
}
return nil
}