Changes to attach to enable per-stream attaching

This allows us to attach to attach to just stdout or stderr or
stdin, or any combination of these.

Signed-off-by: Matthew Heon <matthew.heon@gmail.com>

Closes: #608
Approved by: baude

1 files changed, 14 insertions, 57 deletions

diff --git a/libpod/container_attach.go b/libpod/container_attach.go
index 40d359ddd..2e65755d9 100644
--- a/libpod/container_attach.go
+++ b/libpod/container_attach.go
@@ -5,16 +5,13 @@ import (
 	"io"
 	"net"
 	"os"
-	gosignal "os/signal"
 	"path/filepath"
 
-	"github.com/docker/docker/pkg/signal"
 	"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/crypto/ssh/terminal"
 	"golang.org/x/sys/unix"
 	"k8s.io/client-go/tools/remotecommand"
 )
@@ -26,33 +23,19 @@ const (
 	AttachPipeStderr = 3
 )
 
-// resizeTty handles TTY resizing for Attach()
-func resizeTty(resize chan remotecommand.TerminalSize) {
-	sigchan := make(chan os.Signal, 1)
-	gosignal.Notify(sigchan, signal.SIGWINCH)
-	sendUpdate := func() {
-		winsize, err := term.GetWinsize(os.Stdin.Fd())
-		if err != nil {
-			logrus.Warnf("Could not get terminal size %v", err)
-			return
-		}
-		resize <- remotecommand.TerminalSize{
-			Width:  winsize.Width,
-			Height: winsize.Height,
-		}
+// Attach to the given container
+// Does not check if state is appropriate
+func (c *Container) attach(outputStream, errorStream io.WriteCloser, inputStream io.Reader, keys string, resize <-chan remotecommand.TerminalSize) error {
+	if outputStream == nil && errorStream == nil && inputStream == nil {
+		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 inputStream != nil && !c.config.Stdin {
+		return errors.Wrapf(ErrInvalidArg, "this container was not created as interactive, cannot attach stdin")
 	}
-	go func() {
-		defer close(resize)
-		// Update the terminal size immediately without waiting
-		// for a SIGWINCH to get the correct initial size.
-		sendUpdate()
-		for range sigchan {
-			sendUpdate()
-		}
-	}()
-}
 
-func (c *Container) attach(noStdin bool, keys string) error {
 	// Check the validity of the provided keys first
 	var err error
 	detachKeys := []byte{}
@@ -63,40 +46,14 @@ func (c *Container) attach(noStdin bool, keys string) error {
 		}
 	}
 
-	// TODO: allow resize channel to be passed in for CRI-O use
-	resize := make(chan remotecommand.TerminalSize)
-	if terminal.IsTerminal(int(os.Stdin.Fd())) {
-		resizeTty(resize)
-	} else {
-		defer close(resize)
-	}
-
 	logrus.Debugf("Attaching to container %s", c.ID())
 
-	return c.attachContainerSocket(resize, noStdin, detachKeys)
+	return c.attachContainerSocket(resize, detachKeys, outputStream, errorStream, inputStream)
 }
 
 // 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, noStdIn bool, detachKeys []byte) error {
-	inputStream := os.Stdin
-	outputStream := os.Stdout
-	errorStream := os.Stderr
-	defer inputStream.Close()
-	if terminal.IsTerminal(int(inputStream.Fd())) {
-		oldTermState, err := term.SaveState(inputStream.Fd())
-		if err != nil {
-			return errors.Wrapf(err, "unable to save terminal state")
-		}
-
-		defer term.RestoreTerminal(inputStream.Fd(), oldTermState)
-	}
-
-	// Put both input and output into raw when we have a terminal
-	if !noStdIn && c.config.Spec.Process.Terminal {
-		term.SetRawTerminal(inputStream.Fd())
-	}
-
+func (c *Container) attachContainerSocket(resize <-chan remotecommand.TerminalSize, detachKeys []byte, outputStream, errorStream io.WriteCloser, inputStream io.Reader) error {
 	kubeutils.HandleResizing(resize, func(size remotecommand.TerminalSize) {
 		controlPath := filepath.Join(c.bundlePath(), "ctl")
 		controlFile, err := os.OpenFile(controlPath, unix.O_WRONLY, 0)
@@ -129,7 +86,7 @@ func (c *Container) attachContainerSocket(resize <-chan remotecommand.TerminalSi
 	stdinDone := make(chan error)
 	go func() {
 		var err error
-		if inputStream != nil && !noStdIn {
+		if inputStream != nil {
 			_, err = utils.CopyDetachable(conn, inputStream, detachKeys)
 			conn.CloseWrite()
 		}