v2podman attach and exec

add the ability to attach to a running container.  the tunnel side of this is not enabled yet as we have work on the endpoints and plumbing to do yet.

add the ability to exec a command in a running container.  the tunnel side is also being deferred for same reason.

Signed-off-by: Brent Baude <bbaude@redhat.com>

1 files changed, 103 insertions, 0 deletions

diff --git a/pkg/domain/infra/abi/terminal/terminal.go b/pkg/domain/infra/abi/terminal/terminal.go
new file mode 100644
index 000000000..f187bdd6b
--- /dev/null
+++ b/pkg/domain/infra/abi/terminal/terminal.go
@@ -0,0 +1,103 @@
+// +build ABISupport
+
+package terminal
+
+import (
+	"context"
+	"os"
+	"os/signal"
+
+	lsignal "github.com/containers/libpod/pkg/signal"
+	"github.com/docker/docker/pkg/term"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"k8s.io/client-go/tools/remotecommand"
+)
+
+// RawTtyFormatter ...
+type RawTtyFormatter struct {
+}
+
+// getResize returns a TerminalSize command matching stdin's current
+// size on success, and nil on errors.
+func getResize() *remotecommand.TerminalSize {
+	winsize, err := term.GetWinsize(os.Stdin.Fd())
+	if err != nil {
+		logrus.Warnf("Could not get terminal size %v", err)
+		return nil
+	}
+	return &remotecommand.TerminalSize{
+		Width:  winsize.Width,
+		Height: winsize.Height,
+	}
+}
+
+// Helper for prepareAttach - set up a goroutine to generate terminal resize events
+func resizeTty(ctx context.Context, resize chan remotecommand.TerminalSize) {
+	sigchan := make(chan os.Signal, 1)
+	signal.Notify(sigchan, lsignal.SIGWINCH)
+	go func() {
+		defer close(resize)
+		// Update the terminal size immediately without waiting
+		// for a SIGWINCH to get the correct initial size.
+		resizeEvent := getResize()
+		for {
+			if resizeEvent == nil {
+				select {
+				case <-ctx.Done():
+					return
+				case <-sigchan:
+					resizeEvent = getResize()
+				}
+			} else {
+				select {
+				case <-ctx.Done():
+					return
+				case <-sigchan:
+					resizeEvent = getResize()
+				case resize <- *resizeEvent:
+					resizeEvent = nil
+				}
+			}
+		}
+	}()
+}
+
+func restoreTerminal(state *term.State) error {
+	logrus.SetFormatter(&logrus.TextFormatter{})
+	return term.RestoreTerminal(os.Stdin.Fd(), state)
+}
+
+// Format ...
+func (f *RawTtyFormatter) Format(entry *logrus.Entry) ([]byte, error) {
+	textFormatter := logrus.TextFormatter{}
+	bytes, err := textFormatter.Format(entry)
+
+	if err == nil {
+		bytes = append(bytes, '\r')
+	}
+
+	return bytes, err
+}
+
+func handleTerminalAttach(ctx context.Context, resize chan remotecommand.TerminalSize) (context.CancelFunc, *term.State, error) {
+	logrus.Debugf("Handling terminal attach")
+
+	subCtx, cancel := context.WithCancel(ctx)
+
+	resizeTty(subCtx, resize)
+
+	oldTermState, err := term.SaveState(os.Stdin.Fd())
+	if err != nil {
+		// allow caller to not have to do any cleaning up if we error here
+		cancel()
+		return nil, nil, errors.Wrapf(err, "unable to save terminal state")
+	}
+
+	logrus.SetFormatter(&RawTtyFormatter{})
+	if _, err := term.SetRawTerminal(os.Stdin.Fd()); err != nil {
+		return cancel, nil, err
+	}
+
+	return cancel, oldTermState, nil
+}