Add darwin support for remote-client

Add the ability to cross-compile podman remote for OSX.

Also, add image exists and tag to remote-client.

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

libpod/container_attach_linux.go

@@ -0,0 +1,162 @@
+//+build linux
+
+package libpod
+
+import (
+	"fmt"
+	"io"
+	"net"
+	"os"
+	"path/filepath"
+
+	"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"
+)
+
+//#include <sys/un.h>
+// extern int unix_path_length(){struct sockaddr_un addr; return sizeof(addr.sun_path) - 1;}
+import "C"
+
+/* 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) error {
+	if !streams.AttachOutput && !streams.AttachError && !streams.AttachInput {
+		return errors.Wrapf(ErrInvalidArg, "must provide at least one stream to attach to")
+	}
+
+	// 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, startContainer)
+}
+
+// attachContainerSocket connects to the container's attach socket and deals with the IO
+// TODO add a channel to allow interrupting
+func (c *Container) attachContainerSocket(resize <-chan remotecommand.TerminalSize, detachKeys []byte, streams *AttachStreams, startContainer bool) 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)
+		}
+	})
+
+	socketPath := c.AttachSocketPath()
+
+	maxUnixLength := int(C.unix_path_length())
+	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 startContainer {
+		if err := c.start(); err != nil {
+			return err
+		}
+	}
+
+	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 _, ok := err.(utils.DetachError); ok {
+			return nil
+		}
+		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 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
+}