Implement streaming CRI methods in dockershim

pkg/kubelet/api/services.go

@@ -17,7 +17,7 @@ limitations under the License.
 package api
 
 import (
-	"io"
+	"time"
 
 	runtimeApi "k8s.io/kubernetes/pkg/kubelet/api/v1alpha1/runtime"
 )
@@ -43,8 +43,13 @@ type ContainerManager interface {
 	ListContainers(filter *runtimeApi.ContainerFilter) ([]*runtimeApi.Container, error)
 	// ContainerStatus returns the status of the container.
 	ContainerStatus(containerID string) (*runtimeApi.ContainerStatus, error)
-	// Exec executes a command in the container.
-	Exec(containerID string, cmd []string, tty bool, stdin io.Reader, stdout, stderr io.WriteCloser) error
+	// ExecSync executes a command in the container, and returns the stdout output.
+	// If command exits with a non-zero exit code, an error is returned.
+	ExecSync(containerID string, cmd []string, timeout time.Duration) (stdout []byte, stderr []byte, err error)
+	// Exec prepares a streaming endpoint to execute a command in the container, and returns the address.
+	Exec(*runtimeApi.ExecRequest) (*runtimeApi.ExecResponse, error)
+	// Attach prepares a streaming endpoint to attach to a running container, and returns the address.
+	Attach(req *runtimeApi.AttachRequest) (*runtimeApi.AttachResponse, error)
 }
 
 // PodSandboxManager contains methods for operating on PodSandboxes. The methods
@@ -63,6 +68,8 @@ type PodSandboxManager interface {
 	PodSandboxStatus(podSandboxID string) (*runtimeApi.PodSandboxStatus, error)
 	// ListPodSandbox returns a list of Sandbox.
 	ListPodSandbox(filter *runtimeApi.PodSandboxFilter) ([]*runtimeApi.PodSandbox, error)
+	// PortForward prepares a streaming endpoint to forward ports from a PodSandbox, and returns the address.
+	PortForward(*runtimeApi.PortForwardRequest) (*runtimeApi.PortForwardResponse, error)
 }
 
 // RuntimeService interface should be implemented by a container runtime.

pkg/kubelet/api/testing/fake_runtime_service.go

@@ -18,7 +18,6 @@ package testing
 
 import (
 	"fmt"
-	"io"
 	"reflect"
 	"sync"
 	"time"
@@ -214,6 +213,14 @@ func (r *FakeRuntimeService) ListPodSandbox(filter *runtimeApi.PodSandboxFilter)
 	return result, nil
 }
 
+func (r *FakeRuntimeService) PortForward(*runtimeApi.PortForwardRequest) (*runtimeApi.PortForwardResponse, error) {
+	r.Lock()
+	defer r.Unlock()
+
+	r.Called = append(r.Called, "PortForward")
+	return &runtimeApi.PortForwardResponse{}, nil
+}
+
 func (r *FakeRuntimeService) CreateContainer(podSandboxID string, config *runtimeApi.ContainerConfig, sandboxConfig *runtimeApi.PodSandboxConfig) (string, error) {
 	r.Lock()
 	defer r.Unlock()
@@ -349,12 +356,28 @@ func (r *FakeRuntimeService) ContainerStatus(containerID string) (*runtimeApi.Co
 	return &status, nil
 }
 
-func (r *FakeRuntimeService) Exec(containerID string, cmd []string, tty bool, stdin io.Reader, stdout, stderr io.WriteCloser) error {
+func (r *FakeRuntimeService) ExecSync(containerID string, cmd []string, timeout time.Duration) (stdout []byte, stderr []byte, err error) {
+	r.Lock()
+	defer r.Unlock()
+
+	r.Called = append(r.Called, "ExecSync")
+	return nil, nil, nil
+}
+
+func (r *FakeRuntimeService) Exec(*runtimeApi.ExecRequest) (*runtimeApi.ExecResponse, error) {
 	r.Lock()
 	defer r.Unlock()
 
 	r.Called = append(r.Called, "Exec")
-	return nil
+	return &runtimeApi.ExecResponse{}, nil
+}
+
+func (r *FakeRuntimeService) Attach(req *runtimeApi.AttachRequest) (*runtimeApi.AttachResponse, error) {
+	r.Lock()
+	defer r.Unlock()
+
+	r.Called = append(r.Called, "Attach")
+	return &runtimeApi.AttachResponse{}, nil
 }
 
 func (r *FakeRuntimeService) UpdateRuntimeConfig(runtimeCOnfig *runtimeApi.RuntimeConfig) error {

pkg/kubelet/dockershim/BUILD

@@ -19,6 +19,7 @@ go_library(
         "docker_image.go",
         "docker_sandbox.go",
         "docker_service.go",
+        "docker_streaming.go",
         "helpers.go",
         "legacy.go",
         "naming.go",
@@ -32,7 +33,9 @@ go_library(
         "//pkg/kubelet/dockertools:go_default_library",
         "//pkg/kubelet/leaky:go_default_library",
         "//pkg/kubelet/qos:go_default_library",
+        "//pkg/kubelet/server/streaming:go_default_library",
         "//pkg/kubelet/types:go_default_library",
+        "//pkg/kubelet/util/ioutils:go_default_library",
         "//pkg/util/term:go_default_library",
         "//vendor:github.com/docker/engine-api/types",
         "//vendor:github.com/docker/engine-api/types/container",

pkg/kubelet/dockershim/docker_container.go

@@ -18,7 +18,6 @@ package dockershim
 
 import (
 	"fmt"
-	"io"
 	"os"
 	"path/filepath"
 	"time"
@@ -388,10 +387,3 @@ func (ds *dockerService) ContainerStatus(containerID string) (*runtimeApi.Contai
 		Annotations: annotations,
 	}, nil
 }
-
-// Exec execute a command in the container.
-// TODO: Need to handle terminal resizing before implementing this function.
-// https://github.com/kubernetes/kubernetes/issues/29579.
-func (ds *dockerService) Exec(containerID string, cmd []string, tty bool, stdin io.Reader, stdout, stderr io.WriteCloser) error {
-	return fmt.Errorf("not implemented")
-}

pkg/kubelet/dockershim/docker_service.go

@@ -25,6 +25,7 @@ import (
 	runtimeApi "k8s.io/kubernetes/pkg/kubelet/api/v1alpha1/runtime"
 	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
 	"k8s.io/kubernetes/pkg/kubelet/dockertools"
+	"k8s.io/kubernetes/pkg/kubelet/server/streaming"
 	"k8s.io/kubernetes/pkg/util/term"
 )
 
@@ -55,13 +56,27 @@ const (
 var internalLabelKeys []string = []string{containerTypeLabelKey, containerLogPathLabelKey, sandboxIDLabelKey}
 
 // NOTE: Anything passed to DockerService should be eventually handled in another way when we switch to running the shim as a different process.
-func NewDockerService(client dockertools.DockerInterface, seccompProfileRoot string, podSandboxImage string) DockerService {
-	return &dockerService{
+func NewDockerService(client dockertools.DockerInterface, seccompProfileRoot string, podSandboxImage string, streamingConfig *streaming.Config) (DockerService, error) {
+	ds := &dockerService{
 		seccompProfileRoot: seccompProfileRoot,
 		client:             dockertools.NewInstrumentedDockerInterface(client),
 		os:                 kubecontainer.RealOS{},
 		podSandboxImage:    podSandboxImage,
+		streamingRuntime: &streamingRuntime{
+			client: client,
+			// Only the native exec handling is supported for now.
+			// TODO(#35747) - Either deprecate nsenter exec handling, or add support for it here.
+			execHandler: &dockertools.NativeExecHandler{},
+		},
 	}
+	if streamingConfig != nil {
+		var err error
+		ds.streamingServer, err = streaming.NewServer(*streamingConfig, ds.streamingRuntime)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return ds, nil
 }
 
 // DockerService is an interface that embeds both the new RuntimeService and
@@ -78,11 +93,9 @@ type DockerService interface {
 type DockerLegacyService interface {
 	// Supporting legacy methods for docker.
 	GetContainerLogs(pod *api.Pod, containerID kubecontainer.ContainerID, logOptions *api.PodLogOptions, stdout, stderr io.Writer) (err error)
-	kubecontainer.ContainerAttacher
-	PortForward(sandboxID string, port uint16, stream io.ReadWriteCloser) error
-
-	// TODO: Remove this once exec is properly defined in CRI.
-	ExecInContainer(containerID kubecontainer.ContainerID, cmd []string, stdin io.Reader, stdout, stderr io.WriteCloser, tty bool, resize <-chan term.Size) error
+	LegacyExec(containerID kubecontainer.ContainerID, cmd []string, stdin io.Reader, stdout, stderr io.WriteCloser, tty bool, resize <-chan term.Size) error
+	LegacyAttach(id kubecontainer.ContainerID, stdin io.Reader, stdout, stderr io.WriteCloser, tty bool, resize <-chan term.Size) error
+	LegacyPortForward(sandboxID string, port uint16, stream io.ReadWriteCloser) error
 }
 
 type dockerService struct {
@@ -90,6 +103,8 @@ type dockerService struct {
 	client             dockertools.DockerInterface
 	os                 kubecontainer.OSInterface
 	podSandboxImage    string
+	streamingRuntime   *streamingRuntime
+	streamingServer    streaming.Server
 }
 
 // Version returns the runtime name, runtime version and runtime API version

pkg/kubelet/dockershim/docker_streaming.go

@@ -0,0 +1,149 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package dockershim
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"math"
+	"time"
+
+	dockertypes "github.com/docker/engine-api/types"
+	runtimeapi "k8s.io/kubernetes/pkg/kubelet/api/v1alpha1/runtime"
+	"k8s.io/kubernetes/pkg/kubelet/dockertools"
+	"k8s.io/kubernetes/pkg/kubelet/server/streaming"
+	"k8s.io/kubernetes/pkg/kubelet/util/ioutils"
+	"k8s.io/kubernetes/pkg/util/term"
+)
+
+type streamingRuntime struct {
+	client      dockertools.DockerInterface
+	execHandler dockertools.ExecHandler
+}
+
+var _ streaming.Runtime = &streamingRuntime{}
+
+func (r *streamingRuntime) Exec(containerID string, cmd []string, in io.Reader, out, err io.WriteCloser, tty bool, resize <-chan term.Size) error {
+	return r.exec(containerID, cmd, in, out, err, tty, resize, 0)
+}
+
+// Internal version of Exec adds a timeout.
+func (r *streamingRuntime) exec(containerID string, cmd []string, in io.Reader, out, errw io.WriteCloser, tty bool, resize <-chan term.Size, timeout time.Duration) error {
+	container, err := checkContainerStatus(r.client, containerID)
+	if err != nil {
+		return err
+	}
+
+	// TODO(timstclair): Clean this up once PR#33366 merges.
+	if timeout <= 0 {
+		// Run until command exits.
+		return r.execHandler.ExecInContainer(r.client, container, cmd, in, out, errw, tty, resize)
+	}
+
+	errCh := make(chan error)
+	go func() {
+		errCh <- r.execHandler.ExecInContainer(r.client, container, cmd, in, out, errw, tty, resize)
+	}()
+
+	select {
+	case err := <-errCh:
+		return err
+	case <-time.After(timeout):
+		return streaming.ErrorTimeout("exec", timeout)
+	}
+}
+
+func (r *streamingRuntime) Attach(containerID string, in io.Reader, out, errw io.WriteCloser, resize <-chan term.Size) error {
+	container, err := checkContainerStatus(r.client, containerID)
+	if err != nil {
+		return err
+	}
+
+	tty := container.Config.Tty
+	return dockertools.AttachContainer(r.client, containerID, in, out, errw, tty, resize)
+}
+
+func (r *streamingRuntime) PortForward(podSandboxID string, port int32, stream io.ReadWriteCloser) error {
+	if port < 0 || port > math.MaxUint16 {
+		return fmt.Errorf("invalid port %d", port)
+	}
+	return dockertools.PortForward(r.client, podSandboxID, uint16(port), stream)
+}
+
+// ExecSync executes a command in the container, and returns the stdout output.
+// If command exits with a non-zero exit code, an error is returned.
+func (ds *dockerService) ExecSync(containerID string, cmd []string, timeout time.Duration) (stdout []byte, stderr []byte, err error) {
+	var stdoutBuffer, stderrBuffer bytes.Buffer
+	err = ds.streamingRuntime.exec(containerID, cmd,
+		nil, // in
+		ioutils.WriteCloserWrapper(&stdoutBuffer),
+		ioutils.WriteCloserWrapper(&stderrBuffer),
+		false, // tty
+		nil,   // resize
+		timeout)
+	return stdoutBuffer.Bytes(), stderrBuffer.Bytes(), err
+}
+
+// Exec prepares a streaming endpoint to execute a command in the container, and returns the address.
+func (ds *dockerService) Exec(req *runtimeapi.ExecRequest) (*runtimeapi.ExecResponse, error) {
+	if ds.streamingServer == nil {
+		return nil, streaming.ErrorStreamingDisabled("exec")
+	}
+	_, err := checkContainerStatus(ds.client, req.GetContainerId())
+	if err != nil {
+		return nil, err
+	}
+	return ds.streamingServer.GetExec(req)
+}
+
+// Attach prepares a streaming endpoint to attach to a running container, and returns the address.
+func (ds *dockerService) Attach(req *runtimeapi.AttachRequest) (*runtimeapi.AttachResponse, error) {
+	if ds.streamingServer == nil {
+		return nil, streaming.ErrorStreamingDisabled("attach")
+	}
+	container, err := checkContainerStatus(ds.client, req.GetContainerId())
+	if err != nil {
+		return nil, err
+	}
+	tty := container.Config.Tty
+	return ds.streamingServer.GetAttach(req, tty)
+}
+
+// PortForward prepares a streaming endpoint to forward ports from a PodSandbox, and returns the address.
+func (ds *dockerService) PortForward(req *runtimeapi.PortForwardRequest) (*runtimeapi.PortForwardResponse, error) {
+	if ds.streamingServer == nil {
+		return nil, streaming.ErrorStreamingDisabled("port forward")
+	}
+	_, err := checkContainerStatus(ds.client, req.GetPodSandboxId())
+	if err != nil {
+		return nil, err
+	}
+	// TODO(timstclair): Verify that ports are exposed.
+	return ds.streamingServer.GetPortForward(req)
+}
+
+func checkContainerStatus(client dockertools.DockerInterface, containerID string) (*dockertypes.ContainerJSON, error) {
+	container, err := client.InspectContainer(containerID)
+	if err != nil {
+		return nil, err
+	}
+	if !container.State.Running {
+		return nil, fmt.Errorf("container not running (%s)", container.ID)
+	}
+	return container, nil
+}

pkg/kubelet/dockershim/legacy.go

@@ -17,7 +17,6 @@ limitations under the License.
 package dockershim
 
 import (
-	"fmt"
 	"io"
 
 	"k8s.io/kubernetes/pkg/api"
@@ -31,8 +30,8 @@ import (
 // directly.
 
 // TODO: implement the methods in this file.
-func (ds *dockerService) AttachContainer(id kubecontainer.ContainerID, stdin io.Reader, stdout, stderr io.WriteCloser, tty bool, resize <-chan term.Size) (err error) {
-	return dockertools.AttachContainer(ds.client, id, stdin, stdout, stderr, tty, resize)
+func (ds *dockerService) LegacyAttach(id kubecontainer.ContainerID, stdin io.Reader, stdout, stderr io.WriteCloser, tty bool, resize <-chan term.Size) (err error) {
+	return ds.streamingRuntime.Attach(id.ID, stdin, stdout, stderr, resize)
 }
 
 func (ds *dockerService) GetContainerLogs(pod *api.Pod, containerID kubecontainer.ContainerID, logOptions *api.PodLogOptions, stdout, stderr io.Writer) (err error) {
@@ -43,19 +42,10 @@ func (ds *dockerService) GetContainerLogs(pod *api.Pod, containerID kubecontaine
 	return dockertools.GetContainerLogs(ds.client, pod, containerID, logOptions, stdout, stderr, container.Config.Tty)
 }
 
-func (ds *dockerService) PortForward(sandboxID string, port uint16, stream io.ReadWriteCloser) error {
-	return dockertools.PortForward(ds.client, sandboxID, port, stream)
+func (ds *dockerService) LegacyPortForward(sandboxID string, port uint16, stream io.ReadWriteCloser) error {
+	return ds.streamingRuntime.PortForward(sandboxID, int32(port), stream)
 }
 
-func (ds *dockerService) ExecInContainer(containerID kubecontainer.ContainerID, cmd []string, stdin io.Reader, stdout, stderr io.WriteCloser, tty bool, resize <-chan term.Size) error {
-	container, err := ds.client.InspectContainer(containerID.ID)
-	if err != nil {
-		return err
-	}
-	if !container.State.Running {
-		return fmt.Errorf("container not running (%s)", container.ID)
-	}
-
-	handler := &dockertools.NativeExecHandler{}
-	return handler.ExecInContainer(ds.client, container, cmd, stdin, stdout, stderr, tty, resize)
+func (ds *dockerService) LegacyExec(containerID kubecontainer.ContainerID, cmd []string, stdin io.Reader, stdout, stderr io.WriteCloser, tty bool, resize <-chan term.Size) error {
+	return ds.streamingRuntime.Exec(containerID.ID, cmd, stdin, stdout, stderr, tty, resize)
 }

pkg/kubelet/dockertools/docker_manager.go

@@ -1269,16 +1269,16 @@ func (dm *DockerManager) ExecInContainer(containerID kubecontainer.ContainerID,
 }
 
 func (dm *DockerManager) AttachContainer(containerID kubecontainer.ContainerID, stdin io.Reader, stdout, stderr io.WriteCloser, tty bool, resize <-chan term.Size) error {
-	return AttachContainer(dm.client, containerID, stdin, stdout, stderr, tty, resize)
+	return AttachContainer(dm.client, containerID.ID, stdin, stdout, stderr, tty, resize)
 }
 
 // Temporarily export this function to share with dockershim.
 // TODO: clean this up.
-func AttachContainer(client DockerInterface, containerID kubecontainer.ContainerID, stdin io.Reader, stdout, stderr io.WriteCloser, tty bool, resize <-chan term.Size) error {
+func AttachContainer(client DockerInterface, containerID string, stdin io.Reader, stdout, stderr io.WriteCloser, tty bool, resize <-chan term.Size) error {
 	// Have to start this before the call to client.AttachToContainer because client.AttachToContainer is a blocking
 	// call :-( Otherwise, resize events don't get processed and the terminal never resizes.
 	kubecontainer.HandleResizing(resize, func(size term.Size) {
-		client.ResizeContainerTTY(containerID.ID, int(size.Height), int(size.Width))
+		client.ResizeContainerTTY(containerID, int(size.Height), int(size.Width))
 	})
 
 	// TODO(random-liu): Do we really use the *Logs* field here?
@@ -1294,7 +1294,7 @@ func AttachContainer(client DockerInterface, containerID kubecontainer.Container
 		ErrorStream:  stderr,
 		RawTerminal:  tty,
 	}
-	return client.AttachToContainer(containerID.ID, opts, sopts)
+	return client.AttachToContainer(containerID, opts, sopts)
 }
 
 func noPodInfraContainerError(podName, podNamespace string) error {

pkg/kubelet/kubelet.go

@@ -489,7 +489,10 @@ func NewMainKubelet(kubeCfg *componentconfig.KubeletConfiguration, kubeDeps *Kub
 		case "cri":
 			// Use the new CRI shim for docker. This is needed for testing the
 			// docker integration through CRI, and may be removed in the future.
-			dockerService := dockershim.NewDockerService(klet.dockerClient, kubeCfg.SeccompProfileRoot, kubeCfg.PodInfraContainerImage)
+			dockerService, err := dockershim.NewDockerService(klet.dockerClient, kubeCfg.SeccompProfileRoot, kubeCfg.PodInfraContainerImage, nil)
+			if err != nil {
+				return nil, err
+			}
 			runtimeService := dockerService.(internalApi.RuntimeService)
 			imageService := dockerService.(internalApi.ImageManagerService)
 

pkg/kubelet/kuberuntime/instrumented_services.go

@@ -17,7 +17,6 @@ limitations under the License.
 package kuberuntime
 
 import (
-	"io"
 	"time"
 
 	internalApi "k8s.io/kubernetes/pkg/kubelet/api"
@@ -123,13 +122,31 @@ func (in instrumentedRuntimeService) ContainerStatus(containerID string) (*runti
 	return out, err
 }
 
-func (in instrumentedRuntimeService) Exec(containerID string, cmd []string, tty bool, stdin io.Reader, stdout, stderr io.WriteCloser) error {
+func (in instrumentedRuntimeService) ExecSync(containerID string, cmd []string, timeout time.Duration) ([]byte, []byte, error) {
+	const operation = "exec_sync"
+	defer recordOperation(operation, time.Now())
+
+	stdout, stderr, err := in.service.ExecSync(containerID, cmd, timeout)
+	recordError(operation, err)
+	return stdout, stderr, err
+}
+
+func (in instrumentedRuntimeService) Exec(req *runtimeApi.ExecRequest) (*runtimeApi.ExecResponse, error) {
 	const operation = "exec"
 	defer recordOperation(operation, time.Now())
 
-	err := in.service.Exec(containerID, cmd, tty, stdin, stdout, stderr)
+	resp, err := in.service.Exec(req)
 	recordError(operation, err)
-	return err
+	return resp, err
+}
+
+func (in instrumentedRuntimeService) Attach(req *runtimeApi.AttachRequest) (*runtimeApi.AttachResponse, error) {
+	const operation = "attach"
+	defer recordOperation(operation, time.Now())
+
+	resp, err := in.service.Attach(req)
+	recordError(operation, err)
+	return resp, err
 }
 
 func (in instrumentedRuntimeService) RunPodSandbox(config *runtimeApi.PodSandboxConfig) (string, error) {
@@ -177,6 +194,15 @@ func (in instrumentedRuntimeService) ListPodSandbox(filter *runtimeApi.PodSandbo
 	return out, err
 }
 
+func (in instrumentedRuntimeService) PortForward(req *runtimeApi.PortForwardRequest) (*runtimeApi.PortForwardResponse, error) {
+	const operation = "port_forward"
+	defer recordOperation(operation, time.Now())
+
+	resp, err := in.service.PortForward(req)
+	recordError(operation, err)
+	return resp, err
+}
+
 func (in instrumentedRuntimeService) UpdateRuntimeConfig(runtimeConfig *runtimeApi.RuntimeConfig) error {
 	const operation = "update_runtime_config"
 	defer recordOperation(operation, time.Now())

pkg/kubelet/kuberuntime/kuberuntime_container.go

@@ -668,7 +668,7 @@ func (m *kubeGenericRuntimeManager) AttachContainer(id kubecontainer.ContainerID
 	// now to unblock other tests.
 	// TODO: remove this hack after attach is defined in CRI.
 	if ds, ok := m.runtimeService.(dockershim.DockerLegacyService); ok {
-		return ds.AttachContainer(id, stdin, stdout, stderr, tty, resize)
+		return ds.LegacyAttach(id, stdin, stdout, stderr, tty, resize)
 	}
 	return fmt.Errorf("not implemented")
 }
@@ -694,7 +694,7 @@ func (m *kubeGenericRuntimeManager) ExecInContainer(containerID kubecontainer.Co
 	// now to unblock other tests.
 	// TODO: remove this hack after exec is defined in CRI.
 	if ds, ok := m.runtimeService.(dockershim.DockerLegacyService); ok {
-		return ds.ExecInContainer(containerID, cmd, stdin, stdout, stderr, tty, resize)
+		return ds.LegacyExec(containerID, cmd, stdin, stdout, stderr, tty, resize)
 	}
 	return fmt.Errorf("not implemented")
 }

pkg/kubelet/kuberuntime/kuberuntime_manager.go

@@ -1001,7 +1001,7 @@ func (m *kubeGenericRuntimeManager) PortForward(pod *kubecontainer.Pod, port uin
 	// now to unblock other tests.
 	// TODO: remove this hack after portforward is defined in CRI.
 	if ds, ok := m.runtimeService.(dockershim.DockerLegacyService); ok {
-		return ds.PortForward(pod.Sandboxes[0].ID.ID, port, stream)
+		return ds.LegacyPortForward(pod.Sandboxes[0].ID.ID, port, stream)
 	}
 
 	return fmt.Errorf("not implemented")

pkg/kubelet/remote/BUILD

@@ -22,6 +22,7 @@ go_library(
     deps = [
         "//pkg/kubelet/api:go_default_library",
         "//pkg/kubelet/api/v1alpha1/runtime:go_default_library",
+        "//pkg/util/exec:go_default_library",
         "//vendor:github.com/golang/glog",
         "//vendor:golang.org/x/net/context",
         "//vendor:google.golang.org/grpc",

pkg/kubelet/remote/remote_runtime.go

@@ -17,14 +17,15 @@ limitations under the License.
 package remote
 
 import (
-	"io"
+	"fmt"
+	"strings"
 	"time"
 
-	"fmt"
 	"github.com/golang/glog"
 	"google.golang.org/grpc"
 	internalApi "k8s.io/kubernetes/pkg/kubelet/api"
 	runtimeApi "k8s.io/kubernetes/pkg/kubelet/api/v1alpha1/runtime"
+	utilexec "k8s.io/kubernetes/pkg/util/exec"
 )
 
 // RemoteRuntimeService is a gRPC implementation of internalApi.RuntimeService.
@@ -247,10 +248,75 @@ func (r *RemoteRuntimeService) ContainerStatus(containerID string) (*runtimeApi.
 	return resp.Status, nil
 }
 
-// Exec executes a command in the container.
-// TODO: support terminal resizing for exec, refer https://github.com/kubernetes/kubernetes/issues/29579.
-func (r *RemoteRuntimeService) Exec(containerID string, cmd []string, tty bool, stdin io.Reader, stdout, stderr io.WriteCloser) error {
-	return fmt.Errorf("Not implemented")
+// ExecSync executes a command in the container, and returns the stdout output.
+// If command exits with a non-zero exit code, an error is returned.
+func (r *RemoteRuntimeService) ExecSync(containerID string, cmd []string, timeout time.Duration) (stdout []byte, stderr []byte, err error) {
+	ctx, cancel := getContextWithTimeout(r.timeout)
+	defer cancel()
+
+	timeoutSeconds := int64(timeout.Seconds())
+	req := &runtimeApi.ExecSyncRequest{
+		ContainerId: &containerID,
+		Cmd:         cmd,
+		Timeout:     &timeoutSeconds,
+	}
+	resp, err := r.runtimeClient.ExecSync(ctx, req)
+	if err != nil {
+		glog.Errorf("ExecSync %s '%s' from runtime service failed: %v", containerID, strings.Join(cmd, " "), err)
+		return nil, nil, err
+	}
+
+	err = nil
+	if resp.GetExitCode() != 0 {
+		err = utilexec.CodeExitError{
+			Err:  fmt.Errorf("command '%s' exited with %d: %s", strings.Join(cmd, " "), resp.GetExitCode(), resp.GetStderr()),
+			Code: int(resp.GetExitCode()),
+		}
+	}
+
+	return resp.GetStdout(), resp.GetStderr(), err
+}
+
+// Exec prepares a streaming endpoint to execute a command in the container, and returns the address.
+func (r *RemoteRuntimeService) Exec(req *runtimeApi.ExecRequest) (*runtimeApi.ExecResponse, error) {
+	ctx, cancel := getContextWithTimeout(r.timeout)
+	defer cancel()
+
+	resp, err := r.runtimeClient.Exec(ctx, req)
+	if err != nil {
+		glog.Errorf("Exec %s '%s' from runtime service failed: %v", req.GetContainerId(), strings.Join(req.GetCmd(), " "), err)
+		return nil, err
+	}
+
+	return resp, nil
+}
+
+// Attach prepares a streaming endpoint to attach to a running container, and returns the address.
+func (r *RemoteRuntimeService) Attach(req *runtimeApi.AttachRequest) (*runtimeApi.AttachResponse, error) {
+	ctx, cancel := getContextWithTimeout(r.timeout)
+	defer cancel()
+
+	resp, err := r.runtimeClient.Attach(ctx, req)
+	if err != nil {
+		glog.Errorf("Attach %s from runtime service failed: %v", req.GetContainerId(), err)
+		return nil, err
+	}
+
+	return resp, nil
+}
+
+// PortForward prepares a streaming endpoint to forward ports from a PodSandbox, and returns the address.
+func (r *RemoteRuntimeService) PortForward(req *runtimeApi.PortForwardRequest) (*runtimeApi.PortForwardResponse, error) {
+	ctx, cancel := getContextWithTimeout(r.timeout)
+	defer cancel()
+
+	resp, err := r.runtimeClient.PortForward(ctx, req)
+	if err != nil {
+		glog.Errorf("PortForward %s from runtime service failed: %v", req.GetPodSandboxId(), err)
+		return nil, err
+	}
+
+	return resp, nil
 }
 
 func (r *RemoteRuntimeService) UpdateRuntimeConfig(runtimeConfig *runtimeApi.RuntimeConfig) error {

pkg/kubelet/rktshim/BUILD

@@ -23,6 +23,7 @@ go_library(
     deps = [
         "//pkg/kubelet/api:go_default_library",
         "//pkg/kubelet/api/v1alpha1/runtime:go_default_library",
+        "//pkg/kubelet/util/ioutils:go_default_library",
     ],
 )
 

pkg/kubelet/rktshim/app-interface.go

@@ -17,7 +17,7 @@ limitations under the License.
 package rktshim
 
 import (
-	"io"
+	"time"
 
 	kubeletApi "k8s.io/kubernetes/pkg/kubelet/api"
 	runtimeApi "k8s.io/kubernetes/pkg/kubelet/api/v1alpha1/runtime"
@@ -65,7 +65,18 @@ func (*Runtime) ContainerStatus(string) (*runtimeApi.ContainerStatus, error) {
 	panic("not implemented")
 }
 
-// Exec executes a command inside an app running inside a pod sanbox.
-func (*Runtime) Exec(string, []string, bool, io.Reader, io.WriteCloser, io.WriteCloser) error {
+// ExecSync executes a command in the container, and returns the stdout output.
+// If command exits with a non-zero exit code, an error is returned.
+func (*Runtime) ExecSync(containerID string, cmd []string, timeout time.Duration) (stdout []byte, stderr []byte, err error) {
+	panic("not implemented")
+}
+
+// Exec prepares a streaming endpoint to execute a command in the container, and returns the address.
+func (*Runtime) Exec(*runtimeApi.ExecRequest) (*runtimeApi.ExecResponse, error) {
+	panic("not implemented")
+}
+
+// Attach prepares a streaming endpoint to attach to a running container, and returns the address.
+func (*Runtime) Attach(req *runtimeApi.AttachRequest) (*runtimeApi.AttachResponse, error) {
 	panic("not implemented")
 }

pkg/kubelet/rktshim/fake-app-interface.go

@@ -17,6 +17,7 @@ limitations under the License.
 package rktshim
 
 import (
+	"bytes"
 	"errors"
 	"io"
 	"math/rand"
@@ -24,6 +25,12 @@ import (
 
 	kubeletApi "k8s.io/kubernetes/pkg/kubelet/api"
 	runtimeApi "k8s.io/kubernetes/pkg/kubelet/api/v1alpha1/runtime"
+	"k8s.io/kubernetes/pkg/kubelet/util/ioutils"
+)
+
+const (
+	FakeStreamingHost = "localhost"
+	FakeStreamingPort = "12345"
 )
 
 func init() {
@@ -200,16 +207,34 @@ func (r *FakeRuntime) ContainerStatus(id string) (*runtimeApi.ContainerStatus, e
 	return &c.Status, nil
 }
 
-func (r *FakeRuntime) Exec(id string, cmd []string, tty bool, in io.Reader, out, err io.WriteCloser) error {
-	c, ok := r.Containers[id]
+func (r *FakeRuntime) ExecSync(containerID string, cmd []string, timeout time.Duration) (stdout []byte, stderr []byte, err error) {
+	c, ok := r.Containers[containerID]
 	if !ok {
-		return ErrContainerNotFound
+		return nil, nil, ErrContainerNotFound
 	}
 
 	// TODO(tmrts): Validate the assumption that container has to be running for exec to work.
 	if c.State != runtimeApi.ContainerState_RUNNING {
-		return ErrInvalidContainerStateTransition
+		return nil, nil, ErrInvalidContainerStateTransition
 	}
 
-	return c.Exec(cmd, in, out, err)
+	var stdoutBuffer, stderrBuffer bytes.Buffer
+	err = c.Exec(cmd, nil,
+		ioutils.WriteCloserWrapper(&stdoutBuffer),
+		ioutils.WriteCloserWrapper(&stderrBuffer))
+	return stdoutBuffer.Bytes(), stderrBuffer.Bytes(), err
+}
+
+func (r *FakeRuntime) Exec(req *runtimeApi.ExecRequest) (*runtimeApi.ExecResponse, error) {
+	url := "http://" + FakeStreamingHost + ":" + FakeStreamingPort + "/exec/" + req.GetContainerId()
+	return &runtimeApi.ExecResponse{
+		Url: &url,
+	}, nil
+}
+
+func (r *FakeRuntime) Attach(req *runtimeApi.AttachRequest) (*runtimeApi.AttachResponse, error) {
+	url := "http://" + FakeStreamingHost + ":" + FakeStreamingPort + "/attach/" + req.GetContainerId()
+	return &runtimeApi.AttachResponse{
+		Url: &url,
+	}, nil
 }

pkg/kubelet/rktshim/pod-level-interface.go

@@ -57,3 +57,8 @@ func (*PodSandboxManager) PodSandboxStatus(string) (*runtimeApi.PodSandboxStatus
 func (*PodSandboxManager) ListPodSandbox(*runtimeApi.PodSandboxFilter) ([]*runtimeApi.PodSandbox, error) {
 	panic("not implemented")
 }
+
+// PortForward prepares a streaming endpoint to forward ports from a PodSandbox, and returns the address.
+func (*PodSandboxManager) PortForward(*runtimeApi.PortForwardRequest) (*runtimeApi.PortForwardResponse, error) {
+	panic("not implemented")
+}

pkg/kubelet/server/streaming/BUILD

@@ -12,7 +12,10 @@ load(
 
 go_library(
     name = "go_default_library",
-    srcs = ["server.go"],
+    srcs = [
+        "errors.go",
+        "server.go",
+    ],
     tags = ["automanaged"],
     deps = [
         "//pkg/kubelet/api/v1alpha1/runtime:go_default_library",
@@ -21,6 +24,7 @@ go_library(
         "//pkg/types:go_default_library",
         "//pkg/util/term:go_default_library",
         "//vendor:github.com/emicklei/go-restful",
+        "//vendor:google.golang.org/grpc/codes",
         "//vendor:k8s.io/client-go/pkg/api",
     ],
 )

pkg/kubelet/server/streaming/errors.go

@@ -0,0 +1,47 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package streaming
+
+import (
+	"fmt"
+	"time"
+
+	"google.golang.org/grpc/codes"
+)
+
+type ResponseError struct {
+	Err  string
+	Code codes.Code
+}
+
+func (e *ResponseError) Error() string {
+	return e.Err
+}
+
+func ErrorStreamingDisabled(method string) error {
+	return &ResponseError{
+		Err:  fmt.Sprintf("streaming method %s disabled", method),
+		Code: codes.NotFound,
+	}
+}
+
+func ErrorTimeout(op string, timeout time.Duration) error {
+	return &ResponseError{
+		Err:  fmt.Sprintf("%s timed out after %s", op, timeout.String()),
+		Code: codes.DeadlineExceeded,
+	}
+}