feat: add egctl experimental dashboard envoy-proxy to render the admin dashboard for the proxy

internal/cmd/egctl/config_test.go

@@ -79,6 +79,8 @@ func (fw *fakePortForwarder) Address() string {
 	return fmt.Sprintf("localhost:%d", fw.localPort)
 }
 
+func (fw *fakePortForwarder) WaitForStop() {}
+
 func TestExtractAllConfigDump(t *testing.T) {
 	input, err := readInputConfig("in.all.json")
 	require.NoError(t, err)

internal/cmd/egctl/dashboard.go

@@ -0,0 +1,23 @@
+// Copyright Envoy Gateway Authors
+// SPDX-License-Identifier: Apache-2.0
+// The full text of the Apache license is available in the LICENSE file at
+// the root of the repo.
+
+package egctl
+
+import (
+	"github.com/spf13/cobra"
+)
+
+func newDashboardCommand() *cobra.Command {
+	c := &cobra.Command{
+		Use:     "dashboard",
+		Aliases: []string{"d"},
+		Long:    "Retrieve the dashboard.",
+		Short:   "Retrieve the dashboard.",
+	}
+
+	c.AddCommand(newEnvoyDashboardCmd())
+
+	return c
+}

internal/cmd/egctl/envoy_dashboard.go

@@ -0,0 +1,134 @@
+// Copyright Envoy Gateway Authors
+// SPDX-License-Identifier: Apache-2.0
+// The full text of the Apache license is available in the LICENSE file at
+// the root of the repo.
+
+package egctl
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"os/signal"
+	"runtime"
+
+	"github.com/spf13/cobra"
+	"k8s.io/apimachinery/pkg/types"
+
+	kube "github.com/envoyproxy/gateway/internal/kubernetes"
+)
+
+func newEnvoyDashboardCmd() *cobra.Command {
+	var podName, podNamespace string
+	var listenPort int
+
+	dashboardCmd := &cobra.Command{
+		Use:   "envoy-proxy <name> -n <namespace>",
+		Short: "Retrieves Envoy admin dashboard for the specified pod",
+		Long:  `Retrieve Envoy admin dashboard for the specified pod.`,
+		Example: `  # Retrieve Envoy admin dashboard for the specified pod.
+  egctl experimental dashboard envoy-proxy <pod-name> -n <namespace>
+
+  # short syntax
+  egctl experimental d envoy-proxy <pod-name> -n <namespace>
+`,
+		Aliases: []string{"d"},
+		Args: func(cmd *cobra.Command, args []string) error {
+			if len(args) != 1 && len(labelSelectors) == 0 {
+				cmd.Println(cmd.UsageString())
+				return fmt.Errorf("dashboard requires pod name or label selector")
+			}
+			if len(args) > 0 && len(labelSelectors) > 0 {
+				cmd.Println(cmd.UsageString())
+				return fmt.Errorf("name cannot be provided when a selector is specified")
+			}
+			return nil
+		},
+		RunE: func(c *cobra.Command, args []string) error {
+			kubeClient, err := getCLIClient()
+			if err != nil {
+				return err
+			}
+			if len(args) != 0 {
+				podName = args[0]
+			}
+			if len(labelSelectors) > 0 {
+				pl, err := kubeClient.PodsForSelector(podNamespace, labelSelectors...)
+				if err != nil {
+					return fmt.Errorf("not able to locate pod with selector %s: %w", labelSelectors, err)
+				}
+				if len(pl.Items) < 1 {
+					return errors.New("no pods found")
+				}
+				podName = pl.Items[0].Name
+				podNamespace = pl.Items[0].Namespace
+			}
+
+			return portForward(podName, podNamespace, "http://%s", adminPort, kubeClient, c.OutOrStdout())
+		},
+	}
+	dashboardCmd.PersistentFlags().StringArrayVarP(&labelSelectors, "labels", "l", nil, "Labels to select the envoy proxy pod.")
+	dashboardCmd.PersistentFlags().StringVarP(&podNamespace, "namespace", "n", "envoy-gateway-system", "Namespace where envoy proxy pod are installed.")
+	dashboardCmd.PersistentFlags().IntVarP(&listenPort, "port", "p", 0, "Local port to listen to.")
+
+	return dashboardCmd
+}
+
+// portForward first tries to forward localhost:remotePort to podName:remotePort, falls back to dynamic local port
+func portForward(podName, namespace, urlFormat string, listenPort int, client kube.CLIClient, writer io.Writer) error {
+	var fw kube.PortForwarder
+	meta := types.NamespacedName{
+		Namespace: namespace,
+		Name:      podName,
+	}
+	fw, err := kube.NewLocalPortForwarder(client, meta, listenPort, adminPort)
+	if err != nil {
+		return fmt.Errorf("could not build port forwarder for envoy proxy: %w", err)
+	}
+
+	if err = fw.Start(); err != nil {
+		fw.Stop()
+		return fmt.Errorf("could not start port forwarder for envoy proxy: %w", err)
+	}
+
+	ClosePortForwarderOnInterrupt(fw)
+
+	openBrowser(fmt.Sprintf(urlFormat, fw.Address()), writer)
+
+	fw.WaitForStop()
+
+	return nil
+}
+
+func ClosePortForwarderOnInterrupt(fw kube.PortForwarder) {
+	go func() {
+		signals := make(chan os.Signal, 1)
+		signal.Notify(signals, os.Interrupt)
+		defer signal.Stop(signals)
+		<-signals
+		fw.Stop()
+	}()
+}
+
+func openBrowser(url string, writer io.Writer) {
+	var err error
+
+	fmt.Fprintf(writer, "%s\n", url)
+
+	switch runtime.GOOS {
+	case "linux":
+		err = exec.Command("xdg-open", url).Start()
+	case "windows":
+		err = exec.Command("rundll32", "url.dll,FileProtocolHandler", url).Start()
+	case "darwin":
+		err = exec.Command("open", url).Start()
+	default:
+		fmt.Fprintf(writer, "Unsupported platform %q; open %s in your browser.\n", runtime.GOOS, url)
+	}
+
+	if err != nil {
+		fmt.Fprintf(writer, "Failed to open browser; open %s in your browser.\n", url)
+	}
+}

internal/cmd/egctl/experimental.go

@@ -25,6 +25,7 @@
 	experimentalCommand.AddCommand(newTranslateCommand())
 	experimentalCommand.AddCommand(newStatsCommand())
 	experimentalCommand.AddCommand(newStatusCommand())
+	experimentalCommand.AddCommand(newDashboardCommand())
 
 	return experimentalCommand
 }

internal/kubernetes/port-forwarder.go

@@ -24,6 +24,8 @@ type PortForwarder interface {
 
 	Stop()
 
+	WaitForStop()
+
 	// Address returns the address of the local forwarded address.
 	Address() string
 }
@@ -128,6 +130,10 @@ func (f *localForwarder) Stop() {
 	close(f.stopCh)
 }
 
+func (f *localForwarder) WaitForStop() {
+	<-f.stopCh
+}
+
 func (f *localForwarder) Address() string {
 	return fmt.Sprintf("%s:%d", netutil.DefaultLocalAddress, f.localPort)
 }