Add support for Attach to the kubelet.

This is a pre-cursor to supporting 'kubectl attach ...' and 'kubectl run -it ...'

pkg/kubelet/container/fake_runtime.go

@@ -234,6 +234,14 @@ func (f *FakeRuntime) ExecInContainer(containerID string, cmd []string, stdin io
 	return f.Err
 }
 
+func (f *FakeRuntime) AttachContainer(containerID string, stdin io.Reader, stdout, stderr io.WriteCloser, tty bool) error {
+	f.Lock()
+	defer f.Unlock()
+
+	f.CalledFunctions = append(f.CalledFunctions, "AttachContainer")
+	return f.Err
+}
+
 func (f *FakeRuntime) RunInContainer(containerID string, cmd []string) ([]byte, error) {
 	f.Lock()
 	defer f.Unlock()

pkg/kubelet/container/runtime.go

@@ -77,6 +77,12 @@ type Runtime interface {
 	GetContainerLogs(pod *api.Pod, containerID, tail string, follow bool, stdout, stderr io.Writer) (err error)
 	// ContainerCommandRunner encapsulates the command runner interfaces for testability.
 	ContainerCommandRunner
+	// ContainerAttach encapsulates the attaching to containers for testability
+	ContainerAttacher
+}
+
+type ContainerAttacher interface {
+	AttachContainer(id string, stdin io.Reader, stdout, stderr io.WriteCloser, tty bool) (err error)
 }
 
 // CommandRunner encapsulates the command runner interfaces for testability.

pkg/kubelet/dockertools/docker.go

@@ -71,6 +71,7 @@ type DockerInterface interface {
 	CreateExec(docker.CreateExecOptions) (*docker.Exec, error)
 	StartExec(string, docker.StartExecOptions) error
 	InspectExec(id string) (*docker.ExecInspect, error)
+	AttachToContainer(opts docker.AttachToContainerOptions) error
 }
 
 // KubeletContainerName encapsulates a pod name and a Kubernetes container name.

pkg/kubelet/dockertools/fake_docker_client.go

@@ -298,6 +298,13 @@ func (f *FakeDockerClient) StartExec(_ string, _ docker.StartExecOptions) error
 	return nil
 }
 
+func (f *FakeDockerClient) AttachToContainer(opts docker.AttachToContainerOptions) error {
+	f.Lock()
+	defer f.Unlock()
+	f.called = append(f.called, "attach")
+	return nil
+}
+
 func (f *FakeDockerClient) InspectExec(id string) (*docker.ExecInspect, error) {
 	return f.ExecInspect, f.popError("inspect_exec")
 }

pkg/kubelet/dockertools/instrumented_docker.go

@@ -189,3 +189,12 @@ func (in instrumentedDockerInterface) InspectExec(id string) (*docker.ExecInspec
 	recordError(operation, err)
 	return out, err
 }
+
+func (in instrumentedDockerInterface) AttachToContainer(opts docker.AttachToContainerOptions) error {
+	const operation = "attach"
+	defer recordOperation(operation, time.Now())
+
+	err := in.client.AttachToContainer(opts)
+	recordError(operation, err)
+	return err
+}

pkg/kubelet/dockertools/manager.go

@@ -1006,6 +1006,21 @@ func (dm *DockerManager) ExecInContainer(containerId string, cmd []string, stdin
 	return dm.execHandler.ExecInContainer(dm.client, container, cmd, stdin, stdout, stderr, tty)
 }
 
+func (dm *DockerManager) AttachContainer(containerId string, stdin io.Reader, stdout, stderr io.WriteCloser, tty bool) error {
+	opts := docker.AttachToContainerOptions{
+		Container:    containerId,
+		InputStream:  stdin,
+		OutputStream: stdout,
+		ErrorStream:  stderr,
+		Logs:         true,
+		Stdin:        stdin != nil,
+		Stdout:       stdout != nil,
+		Stderr:       stderr != nil,
+		RawTerminal:  tty,
+	}
+	return dm.client.AttachToContainer(opts)
+}
+
 func noPodInfraContainerError(podName, podNamespace string) error {
 	return fmt.Errorf("cannot find pod infra container in pod %q", kubecontainer.BuildPodFullName(podName, podNamespace))
 }

pkg/kubelet/kubelet.go

@@ -2348,6 +2348,19 @@ func (kl *Kubelet) ExecInContainer(podFullName string, podUID types.UID, contain
 	return kl.runner.ExecInContainer(string(container.ID), cmd, stdin, stdout, stderr, tty)
 }
 
+func (kl *Kubelet) AttachContainer(podFullName string, podUID types.UID, containerName string, stdin io.Reader, stdout, stderr io.WriteCloser, tty bool) error {
+	podUID = kl.podManager.TranslatePodUID(podUID)
+
+	container, err := kl.findContainer(podFullName, podUID, containerName)
+	if err != nil {
+		return err
+	}
+	if container == nil {
+		return fmt.Errorf("container not found (%q)", containerName)
+	}
+	return kl.containerRuntime.AttachContainer(string(container.ID), stdin, stdout, stderr, tty)
+}
+
 // PortForward connects to the pod's port and copies data between the port
 // and the stream.
 func (kl *Kubelet) PortForward(podFullName string, podUID types.UID, port uint16, stream io.ReadWriteCloser) error {

pkg/kubelet/rkt/rkt.go

@@ -18,6 +18,7 @@ package rkt
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -945,6 +946,10 @@ func (r *runtime) RunInContainer(containerID string, cmd []string) ([]byte, erro
 	return []byte(strings.Join(result, "\n")), err
 }
 
+func (r *runtime) AttachContainer(containerID string, stdin io.Reader, stdout, stderr io.WriteCloser, tty bool) error {
+	return errors.New("unimplemented")
+}
+
 // Note: In rkt, the container ID is in the form of "UUID:appName:ImageID", where
 // appName is the container name.
 func (r *runtime) ExecInContainer(containerID string, cmd []string, stdin io.Reader, stdout, stderr io.WriteCloser, tty bool) error {

pkg/kubelet/server.go

@@ -101,6 +101,7 @@ type HostInterface interface {
 	GetPodByName(namespace, name string) (*api.Pod, bool)
 	RunInContainer(name string, uid types.UID, container string, cmd []string) ([]byte, error)
 	ExecInContainer(name string, uid types.UID, container string, cmd []string, in io.Reader, out, err io.WriteCloser, tty bool) error
+	AttachContainer(name string, uid types.UID, container string, in io.Reader, out, err io.WriteCloser, tty bool) error
 	GetKubeletContainerLogs(podFullName, containerName, tail string, follow, previous bool, stdout, stderr io.Writer) error
 	ServeLogs(w http.ResponseWriter, req *http.Request)
 	PortForward(name string, uid types.UID, port uint16, stream io.ReadWriteCloser) error
@@ -140,6 +141,7 @@ func (s *Server) InstallDefaultHandlers() {
 func (s *Server) InstallDebuggingHandlers() {
 	s.mux.HandleFunc("/run/", s.handleRun)
 	s.mux.HandleFunc("/exec/", s.handleExec)
+	s.mux.HandleFunc("/attach/", s.handleAttach)
 	s.mux.HandleFunc("/portForward/", s.handlePortForward)
 
 	s.mux.HandleFunc("/logs/", s.handleLogs)
@@ -367,6 +369,42 @@ func parseContainerCoordinates(path string) (namespace, pod string, uid types.UI
 	return
 }
 
+const streamCreationTimeout = 30 * time.Second
+
+func (s *Server) handleAttach(w http.ResponseWriter, req *http.Request) {
+	u, err := url.ParseRequestURI(req.RequestURI)
+	if err != nil {
+		s.error(w, err)
+		return
+	}
+	podNamespace, podID, uid, container, err := parseContainerCoordinates(u.Path)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+	pod, ok := s.host.GetPodByName(podNamespace, podID)
+	if !ok {
+		http.Error(w, "Pod does not exist", http.StatusNotFound)
+		return
+	}
+
+	stdinStream, stdoutStream, stderrStream, errorStream, conn, tty, ok := s.createStreams(w, req)
+	if conn != nil {
+		defer conn.Close()
+	}
+	if !ok {
+		// error is handled in the createStreams function
+		return
+	}
+
+	err = s.host.AttachContainer(kubecontainer.GetPodFullName(pod), uid, container, stdinStream, stdoutStream, stderrStream, tty)
+	if err != nil {
+		msg := fmt.Sprintf("Error executing command in container: %v", err)
+		glog.Error(msg)
+		errorStream.Write([]byte(msg))
+	}
+}
+
 // handleRun handles requests to run a command inside a container.
 func (s *Server) handleRun(w http.ResponseWriter, req *http.Request) {
 	u, err := url.ParseRequestURI(req.RequestURI)
@@ -394,8 +432,6 @@ func (s *Server) handleRun(w http.ResponseWriter, req *http.Request) {
 	w.Write(data)
 }
 
-const streamCreationTimeout = 30 * time.Second
-
 // handleExec handles requests to run a command inside a container.
 func (s *Server) handleExec(w http.ResponseWriter, req *http.Request) {
 	u, err := url.ParseRequestURI(req.RequestURI)
@@ -413,7 +449,22 @@ func (s *Server) handleExec(w http.ResponseWriter, req *http.Request) {
 		http.Error(w, "Pod does not exist", http.StatusNotFound)
 		return
 	}
+	stdinStream, stdoutStream, stderrStream, errorStream, conn, tty, ok := s.createStreams(w, req)
+	if conn != nil {
+		defer conn.Close()
+	}
+	if !ok {
+		return
+	}
+	err = s.host.ExecInContainer(kubecontainer.GetPodFullName(pod), uid, container, u.Query()[api.ExecCommandParamm], stdinStream, stdoutStream, stderrStream, tty)
+	if err != nil {
+		msg := fmt.Sprintf("Error executing command in container: %v", err)
+		glog.Error(msg)
+		errorStream.Write([]byte(msg))
+	}
+}
 
+func (s *Server) createStreams(w http.ResponseWriter, req *http.Request) (io.Reader, io.WriteCloser, io.WriteCloser, io.WriteCloser, httpstream.Connection, bool, bool) {
 	req.ParseForm()
 	// start at 1 for error stream
 	expectedStreams := 1
@@ -430,7 +481,7 @@ func (s *Server) handleExec(w http.ResponseWriter, req *http.Request) {
 
 	if expectedStreams == 1 {
 		http.Error(w, "You must specify at least 1 of stdin, stdout, stderr", http.StatusBadRequest)
-		return
+		return nil, nil, nil, nil, nil, false, false
 	}
 
 	streamCh := make(chan httpstream.Stream)
@@ -445,9 +496,8 @@ func (s *Server) handleExec(w http.ResponseWriter, req *http.Request) {
 		// The upgrader is responsible for notifying the client of any errors that
 		// occurred during upgrading. All we can do is return here at this point
 		// if we weren't successful in upgrading.
-		return
+		return nil, nil, nil, nil, nil, false, false
 	}
-	defer conn.Close()
 
 	conn.SetIdleTimeout(s.host.StreamingConnectionIdleTimeout())
 
@@ -485,7 +535,7 @@ WaitForStreams:
 			// TODO find a way to return the error to the user. Maybe use a separate
 			// stream to report errors?
 			glog.Error("Timed out waiting for client to create streams")
-			return
+			return nil, nil, nil, nil, nil, false, false
 		}
 	}
 
@@ -494,12 +544,7 @@ WaitForStreams:
 		stdinStream.Close()
 	}
 
-	err = s.host.ExecInContainer(kubecontainer.GetPodFullName(pod), uid, container, u.Query()[api.ExecCommandParamm], stdinStream, stdoutStream, stderrStream, tty)
+	return stdinStream, stdoutStream, stderrStream, errorStream, conn, tty, true
-	if err != nil {
-		msg := fmt.Sprintf("Error executing command in container: %v", err)
-		glog.Error(msg)
-		errorStream.Write([]byte(msg))
-	}
 }
 
 func parsePodCoordinates(path string) (namespace, pod string, uid types.UID, err error) {

pkg/kubelet/server_test.go

@@ -52,6 +52,7 @@ type fakeKubelet struct {
 	runFunc                            func(podFullName string, uid types.UID, containerName string, cmd []string) ([]byte, error)
 	containerVersionFunc               func() (kubecontainer.Version, error)
 	execFunc                           func(pod string, uid types.UID, container string, cmd []string, in io.Reader, out, err io.WriteCloser, tty bool) error
+	attachFunc                         func(pod string, uid types.UID, container string, in io.Reader, out, err io.WriteCloser, tty bool) error
 	portForwardFunc                    func(name string, uid types.UID, port uint16, stream io.ReadWriteCloser) error
 	containerLogsFunc                  func(podFullName, containerName, tail string, follow, pervious bool, stdout, stderr io.Writer) error
 	streamingConnectionIdleTimeoutFunc func() time.Duration
@@ -116,6 +117,10 @@ func (fk *fakeKubelet) ExecInContainer(name string, uid types.UID, container str
 	return fk.execFunc(name, uid, container, cmd, in, out, err, tty)
 }
 
+func (fk *fakeKubelet) AttachContainer(name string, uid types.UID, container string, in io.Reader, out, err io.WriteCloser, tty bool) error {
+	return fk.attachFunc(name, uid, container, in, out, err, tty)
+}
+
 func (fk *fakeKubelet) PortForward(name string, uid types.UID, port uint16, stream io.ReadWriteCloser) error {
 	return fk.portForwardFunc(name, uid, port, stream)
 }
@@ -931,6 +936,237 @@ func TestServeExecInContainer(t *testing.T) {
 	}
 }
 
+// TODO: largely cloned from TestServeExecContainer, refactor and re-use code
+func TestServeAttachContainer(t *testing.T) {
+	tests := []struct {
+		stdin              bool
+		stdout             bool
+		stderr             bool
+		tty                bool
+		responseStatusCode int
+		uid                bool
+	}{
+		{responseStatusCode: http.StatusBadRequest},
+		{stdin: true, responseStatusCode: http.StatusSwitchingProtocols},
+		{stdout: true, responseStatusCode: http.StatusSwitchingProtocols},
+		{stderr: true, responseStatusCode: http.StatusSwitchingProtocols},
+		{stdout: true, stderr: true, responseStatusCode: http.StatusSwitchingProtocols},
+		{stdout: true, stderr: true, tty: true, responseStatusCode: http.StatusSwitchingProtocols},
+		{stdin: true, stdout: true, stderr: true, responseStatusCode: http.StatusSwitchingProtocols},
+	}
+
+	for i, test := range tests {
+		fw := newServerTest()
+
+		fw.fakeKubelet.streamingConnectionIdleTimeoutFunc = func() time.Duration {
+			return 0
+		}
+
+		podNamespace := "other"
+		podName := "foo"
+		expectedPodName := getPodName(podName, podNamespace)
+		expectedUid := "9b01b80f-8fb4-11e4-95ab-4200af06647"
+		expectedContainerName := "baz"
+		expectedStdin := "stdin"
+		expectedStdout := "stdout"
+		expectedStderr := "stderr"
+		attachFuncDone := make(chan struct{})
+		clientStdoutReadDone := make(chan struct{})
+		clientStderrReadDone := make(chan struct{})
+
+		fw.fakeKubelet.attachFunc = func(podFullName string, uid types.UID, containerName string, in io.Reader, out, stderr io.WriteCloser, tty bool) error {
+			defer close(attachFuncDone)
+			if podFullName != expectedPodName {
+				t.Fatalf("%d: podFullName: expected %s, got %s", i, expectedPodName, podFullName)
+			}
+			if test.uid && string(uid) != expectedUid {
+				t.Fatalf("%d: uid: expected %v, got %v", i, expectedUid, uid)
+			}
+			if containerName != expectedContainerName {
+				t.Fatalf("%d: containerName: expected %s, got %s", i, expectedContainerName, containerName)
+			}
+
+			if test.stdin {
+				if in == nil {
+					t.Fatalf("%d: stdin: expected non-nil", i)
+				}
+				b := make([]byte, 10)
+				n, err := in.Read(b)
+				if err != nil {
+					t.Fatalf("%d: error reading from stdin: %v", i, err)
+				}
+				if e, a := expectedStdin, string(b[0:n]); e != a {
+					t.Fatalf("%d: stdin: expected to read %v, got %v", i, e, a)
+				}
+			} else if in != nil {
+				t.Fatalf("%d: stdin: expected nil: %#v", i, in)
+			}
+
+			if test.stdout {
+				if out == nil {
+					t.Fatalf("%d: stdout: expected non-nil", i)
+				}
+				_, err := out.Write([]byte(expectedStdout))
+				if err != nil {
+					t.Fatalf("%d:, error writing to stdout: %v", i, err)
+				}
+				out.Close()
+				<-clientStdoutReadDone
+			} else if out != nil {
+				t.Fatalf("%d: stdout: expected nil: %#v", i, out)
+			}
+
+			if tty {
+				if stderr != nil {
+					t.Fatalf("%d: tty set but received non-nil stderr: %v", i, stderr)
+				}
+			} else if test.stderr {
+				if stderr == nil {
+					t.Fatalf("%d: stderr: expected non-nil", i)
+				}
+				_, err := stderr.Write([]byte(expectedStderr))
+				if err != nil {
+					t.Fatalf("%d:, error writing to stderr: %v", i, err)
+				}
+				stderr.Close()
+				<-clientStderrReadDone
+			} else if stderr != nil {
+				t.Fatalf("%d: stderr: expected nil: %#v", i, stderr)
+			}
+
+			return nil
+		}
+
+		var url string
+		if test.uid {
+			url = fw.testHTTPServer.URL + "/attach/" + podNamespace + "/" + podName + "/" + expectedUid + "/" + expectedContainerName + "?"
+		} else {
+			url = fw.testHTTPServer.URL + "/attach/" + podNamespace + "/" + podName + "/" + expectedContainerName + "?"
+		}
+		if test.stdin {
+			url += "&" + api.ExecStdinParam + "=1"
+		}
+		if test.stdout {
+			url += "&" + api.ExecStdoutParam + "=1"
+		}
+		if test.stderr && !test.tty {
+			url += "&" + api.ExecStderrParam + "=1"
+		}
+		if test.tty {
+			url += "&" + api.ExecTTYParam + "=1"
+		}
+
+		var (
+			resp                *http.Response
+			err                 error
+			upgradeRoundTripper httpstream.UpgradeRoundTripper
+			c                   *http.Client
+		)
+
+		if test.responseStatusCode != http.StatusSwitchingProtocols {
+			c = &http.Client{}
+		} else {
+			upgradeRoundTripper = spdy.NewRoundTripper(nil)
+			c = &http.Client{Transport: upgradeRoundTripper}
+		}
+
+		resp, err = c.Get(url)
+		if err != nil {
+			t.Fatalf("%d: Got error GETing: %v", i, err)
+		}
+		defer resp.Body.Close()
+
+		_, err = ioutil.ReadAll(resp.Body)
+		if err != nil {
+			t.Errorf("%d: Error reading response body: %v", i, err)
+		}
+
+		if e, a := test.responseStatusCode, resp.StatusCode; e != a {
+			t.Fatalf("%d: response status: expected %v, got %v", i, e, a)
+		}
+
+		if test.responseStatusCode != http.StatusSwitchingProtocols {
+			continue
+		}
+
+		conn, err := upgradeRoundTripper.NewConnection(resp)
+		if err != nil {
+			t.Fatalf("Unexpected error creating streaming connection: %s", err)
+		}
+		if conn == nil {
+			t.Fatalf("%d: unexpected nil conn", i)
+		}
+		defer conn.Close()
+
+		h := http.Header{}
+		h.Set(api.StreamType, api.StreamTypeError)
+		errorStream, err := conn.CreateStream(h)
+		if err != nil {
+			t.Fatalf("%d: error creating error stream: %v", i, err)
+		}
+		defer errorStream.Reset()
+
+		if test.stdin {
+			h.Set(api.StreamType, api.StreamTypeStdin)
+			stream, err := conn.CreateStream(h)
+			if err != nil {
+				t.Fatalf("%d: error creating stdin stream: %v", i, err)
+			}
+			defer stream.Reset()
+			_, err = stream.Write([]byte(expectedStdin))
+			if err != nil {
+				t.Fatalf("%d: error writing to stdin stream: %v", i, err)
+			}
+		}
+
+		var stdoutStream httpstream.Stream
+		if test.stdout {
+			h.Set(api.StreamType, api.StreamTypeStdout)
+			stdoutStream, err = conn.CreateStream(h)
+			if err != nil {
+				t.Fatalf("%d: error creating stdout stream: %v", i, err)
+			}
+			defer stdoutStream.Reset()
+		}
+
+		var stderrStream httpstream.Stream
+		if test.stderr && !test.tty {
+			h.Set(api.StreamType, api.StreamTypeStderr)
+			stderrStream, err = conn.CreateStream(h)
+			if err != nil {
+				t.Fatalf("%d: error creating stderr stream: %v", i, err)
+			}
+			defer stderrStream.Reset()
+		}
+
+		if test.stdout {
+			output := make([]byte, 10)
+			n, err := stdoutStream.Read(output)
+			close(clientStdoutReadDone)
+			if err != nil {
+				t.Fatalf("%d: error reading from stdout stream: %v", i, err)
+			}
+			if e, a := expectedStdout, string(output[0:n]); e != a {
+				t.Fatalf("%d: stdout: expected '%v', got '%v'", i, e, a)
+			}
+		}
+
+		if test.stderr && !test.tty {
+			output := make([]byte, 10)
+			n, err := stderrStream.Read(output)
+			close(clientStderrReadDone)
+			if err != nil {
+				t.Fatalf("%d: error reading from stderr stream: %v", i, err)
+			}
+			if e, a := expectedStderr, string(output[0:n]); e != a {
+				t.Fatalf("%d: stderr: expected '%v', got '%v'", i, e, a)
+			}
+		}
+
+		<-attachFuncDone
+	}
+}
+
 func TestServePortForwardIdleTimeout(t *testing.T) {
 	fw := newServerTest()