1 files changed, 147 insertions, 0 deletions
diff --git a/server/container_attach.go b/server/container_attach.go
new file mode 100644
index 000000000..6a822858d
--- /dev/null
+++ b/server/container_attach.go
@@ -0,0 +1,147 @@
+package server
+
+import (
+	"fmt"
+	"io"
+	"net"
+	"os"
+	"path/filepath"
+
+	"github.com/kubernetes-incubator/cri-o/oci"
+	"github.com/kubernetes-incubator/cri-o/utils"
+	"github.com/sirupsen/logrus"
+	"golang.org/x/net/context"
+	"golang.org/x/sys/unix"
+	"k8s.io/client-go/tools/remotecommand"
+	pb "k8s.io/kubernetes/pkg/kubelet/apis/cri/v1alpha1/runtime"
+	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
+)
+
+/* Sync with stdpipe_t in conmon.c */
+const (
+	AttachPipeStdin  = 1
+	AttachPipeStdout = 2
+	AttachPipeStderr = 3
+)
+
+// Attach prepares a streaming endpoint to attach to a running container.
+func (s *Server) Attach(ctx context.Context, req *pb.AttachRequest) (*pb.AttachResponse, error) {
+	logrus.Debugf("AttachRequest %+v", req)
+
+	resp, err := s.GetAttach(req)
+	if err != nil {
+		return nil, fmt.Errorf("unable to prepare attach endpoint")
+	}
+
+	return resp, nil
+}
+
+// Attach endpoint for streaming.Runtime
+func (ss streamService) Attach(containerID string, inputStream io.Reader, outputStream, errorStream io.WriteCloser, tty bool, resize <-chan remotecommand.TerminalSize) error {
+	c := ss.runtimeServer.GetContainer(containerID)
+
+	if c == nil {
+		return fmt.Errorf("could not find container %q", containerID)
+	}
+
+	if err := ss.runtimeServer.Runtime().UpdateStatus(c); err != nil {
+		return err
+	}
+
+	cState := ss.runtimeServer.Runtime().ContainerStatus(c)
+	if !(cState.Status == oci.ContainerStateRunning || cState.Status == oci.ContainerStateCreated) {
+		return fmt.Errorf("container is not created or running")
+	}
+
+	controlPath := filepath.Join(c.BundlePath(), "ctl")
+	controlFile, err := os.OpenFile(controlPath, unix.O_WRONLY, 0)
+	if err != nil {
+		return fmt.Errorf("failed to open container ctl file: %v", err)
+	}
+
+	kubecontainer.HandleResizing(resize, func(size remotecommand.TerminalSize) {
+		logrus.Infof("Got a resize event: %+v", size)
+		_, err := fmt.Fprintf(controlFile, "%d %d %d\n", 1, size.Height, size.Width)
+		if err != nil {
+			logrus.Infof("Failed to write to control file to resize terminal: %v", err)
+		}
+	})
+
+	attachSocketPath := filepath.Join(oci.ContainerAttachSocketDir, c.ID(), "attach")
+	conn, err := net.DialUnix("unixpacket", nil, &net.UnixAddr{Name: attachSocketPath, Net: "unixpacket"})
+	if err != nil {
+		return fmt.Errorf("failed to connect to container %s attach socket: %v", c.ID(), err)
+	}
+	defer conn.Close()
+
+	receiveStdout := make(chan error)
+	if outputStream != nil || errorStream != nil {
+		go func() {
+			receiveStdout <- redirectResponseToOutputStreams(outputStream, errorStream, conn)
+		}()
+	}
+
+	stdinDone := make(chan error)
+	go func() {
+		var err error
+		if inputStream != nil {
+			_, err = utils.CopyDetachable(conn, inputStream, nil)
+			conn.CloseWrite()
+		}
+		stdinDone <- err
+	}()
+
+	select {
+	case err := <-receiveStdout:
+		return err
+	case err := <-stdinDone:
+		if _, ok := err.(utils.DetachError); ok {
+			return nil
+		}
+		if outputStream != nil || errorStream != nil {
+			return <-receiveStdout
+		}
+	}
+
+	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
+			if buf[0] == AttachPipeStdout {
+				dst = outputStream
+			} else if buf[0] == AttachPipeStderr {
+				dst = errorStream
+			} else {
+				logrus.Infof("Got 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
+}