Merge pull request #570 from mrunalp/detach

Detach

conmon/conmon.c

@@ -1002,7 +1002,13 @@ int main(int argc, char *argv[])
 					}
 				} else {
 					num_read = read(masterfd, buf, BUF_SIZE);
-					if (num_read <= 0)
+					if (num_read == 0) {
+						ninfo("Remote socket closed");
+						close(conn_sock);
+						conn_sock = -1;
+						continue;
+					}
+					if (num_read < 0)
 						goto out;
 					ninfo("got data on connection: %d", num_read);
 					if (terminal) {

server/container_attach.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/Sirupsen/logrus"
 	"github.com/kubernetes-incubator/cri-o/oci"
+	"github.com/kubernetes-incubator/cri-o/utils"
 	"golang.org/x/net/context"
 	pb "k8s.io/kubernetes/pkg/kubelet/api/v1alpha1/runtime"
 	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
@@ -74,18 +75,22 @@ func (ss streamService) Attach(containerID string, inputStream io.Reader, output
 		}()
 	}
 
-	stdinDone := make(chan struct{})
+	stdinDone := make(chan error)
 	go func() {
+		var err error
 		if inputStream != nil {
-			io.Copy(conn, inputStream)
+			_, err = utils.CopyDetachable(conn, inputStream, nil)
 		}
-		close(stdinDone)
+		stdinDone <- err
 	}()
 
 	select {
 	case err := <-receiveStdout:
 		return err
-	case <-stdinDone:
+	case err := <-stdinDone:
+		if _, ok := err.(utils.DetachError); ok {
+			return nil
+		}
 		if outputStream != nil || errorStream != nil {
 			return <-receiveStdout
 		}

utils/utils.go

@@ -79,3 +79,63 @@ func newProp(name string, units interface{}) systemdDbus.Property {
 		Value: dbus.MakeVariant(units),
 	}
 }
+
+// DetachError is special error which returned in case of container detach.
+type DetachError struct{}
+
+func (DetachError) Error() string {
+	return "detached from container"
+}
+
+// CopyDetachable is similar to io.Copy but support a detach key sequence to break out.
+func CopyDetachable(dst io.Writer, src io.Reader, keys []byte) (written int64, err error) {
+	if len(keys) == 0 {
+		// Default keys : ctrl-p ctrl-q
+		keys = []byte{16, 17}
+	}
+
+	buf := make([]byte, 32*1024)
+	for {
+		nr, er := src.Read(buf)
+		if nr > 0 {
+			preservBuf := []byte{}
+			for i, key := range keys {
+				preservBuf = append(preservBuf, buf[0:nr]...)
+				if nr != 1 || buf[0] != key {
+					break
+				}
+				if i == len(keys)-1 {
+					// src.Close()
+					return 0, DetachError{}
+				}
+				nr, er = src.Read(buf)
+			}
+			var nw int
+			var ew error
+			if len(preservBuf) > 0 {
+				nw, ew = dst.Write(preservBuf)
+				nr = len(preservBuf)
+			} else {
+				nw, ew = dst.Write(buf[0:nr])
+			}
+			if nw > 0 {
+				written += int64(nw)
+			}
+			if ew != nil {
+				err = ew
+				break
+			}
+			if nr != nw {
+				err = io.ErrShortWrite
+				break
+			}
+		}
+		if er != nil {
+			if er != io.EOF {
+				err = er
+			}
+			break
+		}
+	}
+	return written, err
+}