Merge pull request #3210 from tstromberg/dashboard_on_demand

Use "kubectl proxy" instead of a NodePort to expose the dashboard.

cmd/minikube/cmd/dashboard.go

@@ -17,68 +17,138 @@ limitations under the License.
 package cmd
 
 import (
+	"bufio"
 	"fmt"
+	"net/http"
 	"os"
-	"text/template"
+	"os/exec"
+	"regexp"
 	"time"
 
 	"github.com/golang/glog"
 	"github.com/pkg/browser"
+	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
 	"k8s.io/minikube/pkg/minikube/cluster"
+	"k8s.io/minikube/pkg/minikube/config"
 	"k8s.io/minikube/pkg/minikube/machine"
 	"k8s.io/minikube/pkg/minikube/service"
 
-	commonutil "k8s.io/minikube/pkg/util"
+	"k8s.io/minikube/pkg/util"
 )
 
 var (
 	dashboardURLMode bool
+	// Matches: 127.0.0.1:8001
+	// TODO(tstromberg): Get kubectl to implement a stable supported output format.
+	hostPortRe = regexp.MustCompile(`127.0.0.1:\d{4,}`)
 )
 
 // dashboardCmd represents the dashboard command
 var dashboardCmd = &cobra.Command{
 	Use:   "dashboard",
-	Short: "Opens/displays the kubernetes dashboard URL for your local cluster",
-	Long:  `Opens/displays the kubernetes dashboard URL for your local cluster`,
+	Short: "Access the kubernetes dashboard running within the minikube cluster",
+	Long:  `Access the kubernetes dashboard running within the minikube cluster`,
 	Run: func(cmd *cobra.Command, args []string) {
 		api, err := machine.NewAPIClient()
+		defer func() {
+			err := api.Close()
+			if err != nil {
+				glog.Warningf("Failed to close API: %v", err)
+			}
+		}()
+
 		if err != nil {
-			fmt.Fprintf(os.Stderr, "Error getting client: %s\n", err)
+			fmt.Fprintf(os.Stderr, "Error creating client: %v\n", err)
 			os.Exit(1)
 		}
-		defer api.Close()
-
 		cluster.EnsureMinikubeRunningOrExit(api, 1)
-		namespace := "kube-system"
+
+		ns := "kube-system"
 		svc := "kubernetes-dashboard"
-
-		if err = commonutil.RetryAfter(20, func() error { return service.CheckService(namespace, svc) }, 6*time.Second); err != nil {
-			fmt.Fprintf(os.Stderr, "Could not find finalized endpoint being pointed to by %s: %s\n", svc, err)
+		if err = util.RetryAfter(30, func() error { return service.CheckService(ns, svc) }, 1*time.Second); err != nil {
+			fmt.Fprintf(os.Stderr, "%s:%s is not running: %v\n", ns, svc, err)
 			os.Exit(1)
 		}
 
-		urls, err := service.GetServiceURLsForService(api, namespace, svc, template.Must(template.New("dashboardServiceFormat").Parse(defaultServiceFormatTemplate)))
+		p, hostPort, err := kubectlProxy()
 		if err != nil {
-			fmt.Fprintln(os.Stderr, err)
-			fmt.Fprintln(os.Stderr, "Check that minikube is running.")
-			os.Exit(1)
-		}
-		if len(urls) == 0 {
-			errMsg := "There appears to be no url associated with dashboard, this is not expected, exiting"
-			glog.Infoln(errMsg)
+			glog.Fatalf("kubectl proxy: %v", err)
+		}
+		url := dashboardURL(hostPort, ns, svc)
+
+		if err = util.RetryAfter(60, func() error { return checkURL(url) }, 1*time.Second); err != nil {
+			fmt.Fprintf(os.Stderr, "%s is not responding properly: %v\n", url, err)
 			os.Exit(1)
 		}
+
 		if dashboardURLMode {
-			fmt.Fprintln(os.Stdout, urls[0])
+			fmt.Fprintln(os.Stdout, url)
 		} else {
-			fmt.Fprintln(os.Stdout, "Opening kubernetes dashboard in default browser...")
-			browser.OpenURL(urls[0])
+			fmt.Fprintln(os.Stdout, fmt.Sprintf("Opening %s in your default browser...", url))
+			if err = browser.OpenURL(url); err != nil {
+				fmt.Fprintf(os.Stderr, fmt.Sprintf("failed to open browser: %v", err))
+			}
+		}
+
+		glog.Infof("Waiting forever for kubectl proxy to exit ...")
+		if err = p.Wait(); err != nil {
+			glog.Errorf("Wait: %v", err)
 		}
 	},
 }
 
+// kubectlProxy runs "kubectl proxy", returning host:port
+func kubectlProxy() (*exec.Cmd, string, error) {
+	path, err := exec.LookPath("kubectl")
+	if err != nil {
+		return nil, "", errors.Wrap(err, "kubectl not found in PATH")
+	}
+
+	// port=0 picks a random system port
+	// config.GetMachineName() respects the -p (profile) flag
+	cmd := exec.Command(path, "--context", config.GetMachineName(), "proxy", "--port=0")
+	stdoutPipe, err := cmd.StdoutPipe()
+	if err != nil {
+		return nil, "", errors.Wrap(err, "cmd stdout")
+	}
+
+	glog.Infof("Executing: %s %s", cmd.Path, cmd.Args)
+	if err := cmd.Start(); err != nil {
+		return nil, "", errors.Wrap(err, "proxy start")
+	}
+	reader := bufio.NewReader(stdoutPipe)
+	glog.Infof("proxy started, reading stdout pipe ...")
+	out, err := reader.ReadString('\n')
+	if err != nil {
+		return nil, "", errors.Wrap(err, "reading stdout pipe")
+	}
+	glog.Infof("proxy stdout: %s", out)
+	return cmd, hostPortRe.FindString(out), nil
+}
+
+// dashboardURL generates a URL for accessing the dashboard service
+func dashboardURL(proxy string, ns string, svc string) string {
+	// Reference: https://github.com/kubernetes/dashboard/wiki/Accessing-Dashboard---1.7.X-and-above
+	return fmt.Sprintf("http://%s/api/v1/namespaces/%s/services/http:%s:/proxy/", proxy, ns, svc)
+}
+
+// checkURL checks if a URL returns 200 HTTP OK
+func checkURL(url string) error {
+	resp, err := http.Get(url)
+	glog.Infof("%s response: %v %+v", url, err, resp)
+	if err != nil {
+		return errors.Wrap(err, "checkURL")
+	}
+	if resp.StatusCode != http.StatusOK {
+		return &util.RetriableError{
+			Err: fmt.Errorf("unexpected response code: %d", resp.StatusCode),
+		}
+	}
+	return nil
+}
+
 func init() {
-	dashboardCmd.Flags().BoolVar(&dashboardURLMode, "url", false, "Display the kubernetes dashboard in the CLI instead of opening it in the default browser")
+	dashboardCmd.Flags().BoolVar(&dashboardURLMode, "url", false, "Display dashboard URL instead of opening a browser")
 	RootCmd.AddCommand(dashboardCmd)
 }

deploy/addons/dashboard/dashboard-svc.yaml

@@ -24,10 +24,8 @@ metadata:
     kubernetes.io/minikube-addons: dashboard
     kubernetes.io/minikube-addons-endpoint: dashboard
 spec:
-  type: NodePort
   ports:
   - port: 80
     targetPort: 9090
-    nodePort: 30000
   selector:
     app: kubernetes-dashboard

pkg/minikube/service/service.go

@@ -25,6 +25,8 @@ import (
 	"time"
 
 	"github.com/docker/machine/libmachine"
+	"github.com/golang/glog"
+
 	"github.com/pkg/browser"
 	"github.com/pkg/errors"
 	"k8s.io/api/core/v1"
@@ -189,45 +191,23 @@ func printURLsForService(c corev1.CoreV1Interface, ip, service, namespace string
 	return urls, nil
 }
 
-// CheckService waits for the specified service to be ready by returning an error until the service is up
-// The check is done by polling the endpoint associated with the service and when the endpoint exists, returning no error->service-online
+// CheckService checks if a service is listening on a port.
 func CheckService(namespace string, service string) error {
 	client, err := K8s.GetCoreClient()
 	if err != nil {
 		return errors.Wrap(err, "Error getting kubernetes client")
 	}
-	services := client.Services(namespace)
-	err = validateService(services, service)
-	if err != nil {
-		return errors.Wrap(err, "Error validating service")
-	}
-	endpoints := client.Endpoints(namespace)
-	return checkEndpointReady(endpoints, service)
-}
 
-func validateService(s corev1.ServiceInterface, service string) error {
-	if _, err := s.Get(service, metav1.GetOptions{}); err != nil {
-		return errors.Wrapf(err, "Error getting service %s", service)
-	}
-	return nil
-}
-
-func checkEndpointReady(endpoints corev1.EndpointsInterface, service string) error {
-	endpoint, err := endpoints.Get(service, metav1.GetOptions{})
+	svc, err := client.Services(namespace).Get(service, metav1.GetOptions{})
 	if err != nil {
-		return &util.RetriableError{Err: errors.Errorf("Error getting endpoints for service %s", service)}
-	}
-	const notReadyMsg = "Waiting, endpoint for service is not ready yet...\n"
-	if len(endpoint.Subsets) == 0 {
-		fmt.Fprintf(os.Stderr, notReadyMsg)
-		return &util.RetriableError{Err: errors.New("Endpoint for service is not ready yet")}
-	}
-	for _, subset := range endpoint.Subsets {
-		if len(subset.Addresses) == 0 {
-			fmt.Fprintf(os.Stderr, notReadyMsg)
-			return &util.RetriableError{Err: errors.New("No endpoints for service are ready yet")}
+		return &util.RetriableError{
+			Err: errors.Wrapf(err, "Error getting service %s", service),
 		}
 	}
+	if len(svc.Spec.Ports) == 0 {
+		return fmt.Errorf("%s:%s has no ports", namespace, service)
+	}
+	glog.Infof("Found service: %+v", svc)
 	return nil
 }
 

pkg/minikube/service/service_test.go

@@ -133,44 +133,6 @@ func (e MockEndpointsInterface) Get(name string, _ metav1.GetOptions) (*v1.Endpo
 	return endpoint, nil
 }
 
-func TestCheckEndpointReady(t *testing.T) {
-	var tests = []struct {
-		description string
-		service     string
-		err         bool
-	}{
-		{
-			description: "Endpoint with no subsets should return an error",
-			service:     "no-subsets",
-			err:         true,
-		},
-		{
-			description: "Endpoint with no ready endpoints should return an error",
-			service:     "not-ready",
-			err:         true,
-		},
-		{
-			description: "Endpoint with at least one ready endpoint should not return an error",
-			service:     "one-ready",
-			err:         false,
-		},
-	}
-
-	for _, test := range tests {
-		test := test
-		t.Run(test.description, func(t *testing.T) {
-			t.Parallel()
-			err := checkEndpointReady(&MockEndpointsInterface{}, test.service)
-			if err != nil && !test.err {
-				t.Errorf("Check endpoints returned an error: %+v", err)
-			}
-			if err == nil && test.err {
-				t.Errorf("Check endpoints should have returned an error but returned nil")
-			}
-		})
-	}
-}
-
 type MockServiceInterface struct {
 	fake.FakeServices
 	ServiceList *v1.ServiceList

pkg/util/utils.go

@@ -97,14 +97,17 @@ func Retry(attempts int, callback func() error) (err error) {
 func RetryAfter(attempts int, callback func() error, d time.Duration) (err error) {
 	m := MultiError{}
 	for i := 0; i < attempts; i++ {
+		glog.V(1).Infof("retry loop %d", i)
 		err = callback()
 		if err == nil {
 			return nil
 		}
 		m.Collect(err)
 		if _, ok := err.(*RetriableError); !ok {
+			glog.Infof("non-retriable error: %v", err)
 			return m.ToError()
 		}
+		glog.V(2).Infof("sleeping %s", d)
 		time.Sleep(d)
 	}
 	return m.ToError()

test/integration/addons_test.go

@@ -19,9 +19,10 @@ limitations under the License.
 package integration
 
 import (
-	"errors"
 	"fmt"
+	"io/ioutil"
 	"net"
+	"net/http"
 	"net/url"
 	"path/filepath"
 	"strings"
@@ -49,34 +50,45 @@ func testDashboard(t *testing.T) {
 	t.Parallel()
 	minikubeRunner := NewMinikubeRunner(t)
 
-	var u *url.URL
-
-	checkDashboard := func() error {
-		var err error
-		dashboardURL := minikubeRunner.RunCommand("dashboard --url", false)
-		if dashboardURL == "" {
-			return errors.New("error getting dashboard URL")
-		}
-		u, err = url.Parse(strings.TrimSpace(dashboardURL))
+	cmd, out := minikubeRunner.RunDaemon("dashboard --url")
+	defer func() {
+		err := cmd.Process.Kill()
 		if err != nil {
-			return err
+			t.Logf("Failed to kill mount command: %v", err)
 		}
-		return nil
+	}()
+
+	s, err := out.ReadString('\n')
+	if err != nil {
+		t.Fatalf("failed to read url: %v", err)
 	}
 
-	if err := util.Retry(t, checkDashboard, 2*time.Second, 60); err != nil {
-		t.Fatalf("error checking dashboard URL: %v", err)
+	u, err := url.Parse(strings.TrimSpace(s))
+	if err != nil {
+		t.Fatalf("failed to parse %q: %v", s, err)
 	}
 
 	if u.Scheme != "http" {
-		t.Fatalf("wrong scheme in dashboard URL, expected http, actual %s", u.Scheme)
+		t.Errorf("got Scheme %s, expected http", u.Scheme)
 	}
-	_, port, err := net.SplitHostPort(u.Host)
+	host, _, err := net.SplitHostPort(u.Host)
 	if err != nil {
-		t.Fatalf("failed to split dashboard host %s: %v", u.Host, err)
+		t.Fatalf("failed SplitHostPort: %v", err)
 	}
-	if port != "30000" {
-		t.Fatalf("Dashboard is exposed on wrong port, expected 30000, actual %s", port)
+	if host != "127.0.0.1" {
+		t.Errorf("got host %s, expected 127.0.0.1", host)
+	}
+
+	resp, err := http.Get(u.String())
+	if err != nil {
+		t.Fatalf("failed get: %v", err)
+	}
+	if resp.StatusCode != http.StatusOK {
+		body, err := ioutil.ReadAll(resp.Body)
+		if err != nil {
+			t.Fatalf("Unable to read http response body: %v", err)
+		}
+		t.Errorf("%s returned status code %d, expected %d.\nbody:\n%s", u, resp.StatusCode, http.StatusOK, body)
 	}
 }
 

test/integration/mount_test.go

@@ -46,7 +46,7 @@ func testMounting(t *testing.T) {
 	defer os.RemoveAll(tempDir)
 
 	mountCmd := fmt.Sprintf("mount %s:/mount-9p", tempDir)
-	cmd := minikubeRunner.RunDaemon(mountCmd)
+	cmd, _ := minikubeRunner.RunDaemon(mountCmd)
 	defer func() {
 		err := cmd.Process.Kill()
 		if err != nil {

test/integration/util/util.go

@@ -17,6 +17,7 @@ limitations under the License.
 package util
 
 import (
+	"bufio"
 	"bytes"
 	"encoding/json"
 	"fmt"
@@ -81,15 +82,21 @@ func (m *MinikubeRunner) RunCommand(command string, checkError bool) string {
 	return string(stdout)
 }
 
-func (m *MinikubeRunner) RunDaemon(command string) *exec.Cmd {
+func (m *MinikubeRunner) RunDaemon(command string) (*exec.Cmd, *bufio.Reader) {
 	commandArr := strings.Split(command, " ")
 	path, _ := filepath.Abs(m.BinaryPath)
 	cmd := exec.Command(path, commandArr...)
-	err := cmd.Start()
+	stdoutPipe, err := cmd.StdoutPipe()
 	if err != nil {
-		m.T.Fatalf("Error running command: %s %s", command, err)
+		m.T.Fatalf("stdout pipe failed: %v", err)
 	}
-	return cmd
+
+	err = cmd.Start()
+	if err != nil {
+		m.T.Fatalf("Error running command: %s %v", command, err)
+	}
+	return cmd, bufio.NewReader(stdoutPipe)
+
 }
 
 func (m *MinikubeRunner) SSH(command string) (string, error) {