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//+build linux
package libpod
import (
"fmt"
"io"
"net"
"os"
"path/filepath"
"github.com/containers/libpod/libpod/define"
"github.com/containers/libpod/pkg/kubeutils"
"github.com/containers/libpod/utils"
"github.com/docker/docker/pkg/term"
"github.com/pkg/errors"
"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
)
// Attach to the given container
// Does not check if state is appropriate
func (c *Container) attach(streams *AttachStreams, keys string, resize <-chan remotecommand.TerminalSize, startContainer bool, started chan bool) error {
if !streams.AttachOutput && !streams.AttachError && !streams.AttachInput {
return errors.Wrapf(define.ErrInvalidArg, "must provide at least one stream to attach to")
}
logrus.Debugf("Attaching to container %s", c.ID())
return c.attachContainerSocket(resize, keys, streams, startContainer, started)
}
// attachContainerSocket connects to the container's attach socket and deals with the IO.
// started is only required if startContainer is true
// TODO add a channel to allow interrupting
func (c *Container) attachContainerSocket(resize <-chan remotecommand.TerminalSize, keys string, streams *AttachStreams, startContainer bool, started chan bool) error {
if startContainer && started == nil {
return errors.Wrapf(define.ErrInternal, "started chan not passed when startContainer set")
}
// Use default detach keys when keys aren't passed or specified in libpod.conf
if len(keys) == 0 {
keys = DefaultDetachKeys
}
// Check the validity of the provided keys
detachKeys := []byte{}
var err error
detachKeys, err = term.ToBytes(keys)
if err != nil {
return errors.Wrapf(err, "invalid detach keys")
}
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)
}
})
socketPath := c.AttachSocketPath()
maxUnixLength := unixPathLength()
if maxUnixLength < len(socketPath) {
socketPath = socketPath[0:maxUnixLength]
}
logrus.Debug("connecting to socket ", socketPath)
conn, err := net.DialUnix("unixpacket", nil, &net.UnixAddr{Name: socketPath, Net: "unixpacket"})
if err != nil {
return errors.Wrapf(err, "failed to connect to container's attach socket: %v", socketPath)
}
defer conn.Close()
// If starting was requested, start the container and notify when that's
// done.
if startContainer {
if err := c.start(); err != nil {
return err
}
started <- true
}
receiveStdoutError := make(chan error)
go func() {
receiveStdoutError <- redirectResponseToOutputStreams(streams.OutputStream, streams.ErrorStream, streams.AttachOutput, streams.AttachError, 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 err == define.ErrDetach {
return err
}
if streams.AttachOutput || streams.AttachError {
return <-receiveStdoutError
}
}
return nil
}
func redirectResponseToOutputStreams(outputStream, errorStream io.Writer, writeOutput, writeError bool, 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
var doWrite bool
switch buf[0] {
case AttachPipeStdout:
dst = outputStream
doWrite = writeOutput
case AttachPipeStderr:
dst = errorStream
doWrite = writeError
default:
logrus.Infof("Received unexpected attach type %+d", buf[0])
}
if dst == nil {
return errors.New("output destination cannot be nil")
}
if doWrite {
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
}
|
