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package libpod
import (
"fmt"
"io"
"net"
"os"
"path/filepath"
"github.com/docker/docker/pkg/term"
"github.com/pkg/errors"
"github.com/projectatomic/libpod/pkg/kubeutils"
"github.com/projectatomic/libpod/utils"
"github.com/sirupsen/logrus"
"golang.org/x/sys/unix"
"k8s.io/client-go/tools/remotecommand"
)
/* Sync with stdpipe_t in conmon.c */
const (
AttachPipeStdin = 1
AttachPipeStdout = 2
AttachPipeStderr = 3
)
// AttachStreams contains streams that will be attached to the container
type AttachStreams struct {
// OutputStream will be attached to container's STDOUT
OutputStream io.WriteCloser
// ErrorStream will be attached to container's STDERR
ErrorStream io.WriteCloser
// InputStream will be attached to container's STDIN
InputStream io.Reader
// AttachOutput is whether to attach to STDOUT
// If false, stdout will not be attached
AttachOutput bool
// AttachError is whether to attach to STDERR
// If false, stdout will not be attached
AttachError bool
// AttachInput is whether to attach to STDIN
// If false, stdout will not be attached
AttachInput bool
}
// Attach to the given container
// Does not check if state is appropriate
func (c *Container) attach(streams *AttachStreams, keys string, resize <-chan remotecommand.TerminalSize) error {
if !streams.AttachOutput && !streams.AttachError && !streams.AttachInput {
return errors.Wrapf(ErrInvalidArg, "must provide at least one stream to attach to")
}
// Do not allow stdin on containers without Stdin set
// Conmon was not configured properly
if streams.AttachInput && !c.config.Stdin {
return errors.Wrapf(ErrInvalidArg, "this container was not created as interactive, cannot attach stdin")
}
// Check the validity of the provided keys first
var err error
detachKeys := []byte{}
if len(keys) > 0 {
detachKeys, err = term.ToBytes(keys)
if err != nil {
return errors.Wrapf(err, "invalid detach keys")
}
}
logrus.Debugf("Attaching to container %s", c.ID())
return c.attachContainerSocket(resize, detachKeys, streams)
}
// attachContainerSocket connects to the container's attach socket and deals with the IO
// TODO add a channel to allow interruptiong
func (c *Container) attachContainerSocket(resize <-chan remotecommand.TerminalSize, detachKeys []byte, streams *AttachStreams) error {
kubeutils.HandleResizing(resize, func(size remotecommand.TerminalSize) {
controlPath := filepath.Join(c.bundlePath(), "ctl")
controlFile, err := os.OpenFile(controlPath, unix.O_WRONLY, 0)
if err != nil {
logrus.Debugf("Could not open ctl file: %v", err)
return
}
defer controlFile.Close()
logrus.Debugf("Received a resize event: %+v", size)
if _, err = fmt.Fprintf(controlFile, "%d %d %d\n", 1, size.Height, size.Width); err != nil {
logrus.Warnf("Failed to write to control file to resize terminal: %v", err)
}
})
logrus.Debug("connecting to socket ", c.attachSocketPath())
conn, err := net.DialUnix("unixpacket", nil, &net.UnixAddr{Name: c.attachSocketPath(), Net: "unixpacket"})
if err != nil {
return errors.Wrapf(err, "failed to connect to container's attach socket: %v")
}
defer conn.Close()
receiveStdoutError := make(chan error)
if streams.AttachOutput || streams.AttachError {
go func() {
receiveStdoutError <- redirectResponseToOutputStreams(streams.OutputStream, streams.ErrorStream, conn)
}()
}
stdinDone := make(chan error)
go func() {
var err error
if streams.AttachInput {
_, err = utils.CopyDetachable(conn, streams.InputStream, detachKeys)
conn.CloseWrite()
}
stdinDone <- err
}()
select {
case err := <-receiveStdoutError:
return err
case err := <-stdinDone:
if _, ok := err.(utils.DetachError); ok {
return nil
}
if streams.AttachOutput || streams.AttachError {
return <-receiveStdoutError
}
}
return nil
}
func redirectResponseToOutputStreams(outputStream, errorStream io.Writer, conn io.Reader) error {
var err error
buf := make([]byte, 8192+1) /* Sync with conmon STDIO_BUF_SIZE */
for {
nr, er := conn.Read(buf)
if nr > 0 {
var dst io.Writer
switch buf[0] {
case AttachPipeStdout:
dst = outputStream
case AttachPipeStderr:
dst = errorStream
default:
logrus.Infof("Received unexpected attach type %+d", buf[0])
}
if dst != nil {
nw, ew := dst.Write(buf[1:nr])
if ew != nil {
err = ew
break
}
if nr != nw+1 {
err = io.ErrShortWrite
break
}
}
}
if er == io.EOF {
break
}
if er != nil {
err = er
break
}
}
return err
}
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