Backport of NET 6409 into release/1.1.x (#3185)

* backport of commit de72bfd

* NET 6409 (#3158)

* init

* fix help and synopsis

* added some tests

* change log

* some fixes

* rename var name

* tests for get envoy stats

* fix tests

* Update cli/cmd/envoy-stats/envoy_stats.go

Co-authored-by: Thomas Eckert <[email protected]>

* proxy stats command

* fix command options

* pr comment resolved

* fix globaloptions

* fix lint

---------

Co-authored-by: Thomas Eckert <[email protected]>

* removed envoy stats

---------

Co-authored-by: absolutelightning <[email protected]>
Co-authored-by: Ashesh Vidyut <[email protected]>
Co-authored-by: Thomas Eckert <[email protected]>

.changelog/3158.txt

@@ -0,0 +1,3 @@
+```release-note:improvement
+cli: Add consul-k8s proxy stats command line interface that outputs the localhost:19000/stats of envoy in the pod
+```

cli/cmd/proxy/stats/command.go

@@ -0,0 +1,222 @@
+package stats
+
+import (
+	"errors"
+	"fmt"
+	"github.com/hashicorp/consul-k8s/cli/common"
+	"github.com/hashicorp/consul-k8s/cli/common/flag"
+	"github.com/hashicorp/consul-k8s/cli/common/terminal"
+	"github.com/hashicorp/consul-k8s/cli/helm"
+	helmCLI "helm.sh/helm/v3/pkg/cli"
+	"io"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/rest"
+	"net/http"
+	"strconv"
+	"strings"
+	"sync"
+)
+
+const envoyAdminPort = 19000
+
+type StatsCommand struct {
+	*common.BaseCommand
+
+	helmActionsRunner helm.HelmActionsRunner
+
+	kubernetes kubernetes.Interface
+
+	restConfig *rest.Config
+
+	set *flag.Sets
+
+	flagKubeConfig  string
+	flagKubeContext string
+	flagNamespace   string
+	flagPod         string
+
+	once sync.Once
+	help string
+}
+
+func (c *StatsCommand) init() {
+	c.set = flag.NewSets()
+	if c.helmActionsRunner == nil {
+		c.helmActionsRunner = &helm.ActionRunner{}
+	}
+
+	f := c.set.NewSet("Command Options")
+	f.StringVar(&flag.StringVar{
+		Name:    "namespace",
+		Target:  &c.flagNamespace,
+		Usage:   "The namespace where the target Pod can be found.",
+		Aliases: []string{"n"},
+	})
+
+	f = c.set.NewSet("Global Options")
+	f.StringVar(&flag.StringVar{
+		Name:    "kubeconfig",
+		Aliases: []string{"c"},
+		Target:  &c.flagKubeConfig,
+		Default: "",
+		Usage:   "Path to kubeconfig file.",
+	})
+	f.StringVar(&flag.StringVar{
+		Name:    "context",
+		Target:  &c.flagKubeContext,
+		Default: "",
+		Usage:   "Kubernetes context to use.",
+	})
+
+	c.help = c.set.Help()
+}
+
+// validateFlags checks the command line flags and values for errors.
+func (c *StatsCommand) validateFlags() error {
+	if len(c.set.Args()) > 0 {
+		return errors.New("should have no non-flag arguments")
+	}
+	return nil
+}
+
+func (c *StatsCommand) Run(args []string) int {
+	c.once.Do(c.init)
+
+	if err := c.parseFlags(args); err != nil {
+		c.UI.Output(err.Error(), terminal.WithErrorStyle())
+		c.UI.Output("\n" + c.Help())
+		return 1
+	}
+
+	if err := c.validateFlags(); err != nil {
+		c.UI.Output(err.Error())
+		return 1
+	}
+
+	if c.flagPod == "" {
+		c.UI.Output("pod name is required")
+		return 1
+	}
+
+	// helmCLI.New() will create a settings object which is used by the Helm Go SDK calls.
+	settings := helmCLI.New()
+	if c.flagKubeConfig != "" {
+		settings.KubeConfig = c.flagKubeConfig
+	}
+	if c.flagKubeContext != "" {
+		settings.KubeContext = c.flagKubeContext
+	}
+
+	if c.flagNamespace == "" {
+		c.flagNamespace = settings.Namespace()
+	}
+
+	if err := c.setupKubeClient(settings); err != nil {
+		c.UI.Output(err.Error(), terminal.WithErrorStyle())
+		return 1
+	}
+
+	if c.restConfig == nil {
+		var err error
+		if c.restConfig, err = settings.RESTClientGetter().ToRESTConfig(); err != nil {
+			c.UI.Output("error setting rest config")
+			return 1
+		}
+	}
+
+	pf := common.PortForward{
+		Namespace:  c.flagNamespace,
+		PodName:    c.flagPod,
+		RemotePort: envoyAdminPort,
+		KubeClient: c.kubernetes,
+		RestConfig: c.restConfig,
+	}
+
+	stats, err := c.getEnvoyStats(&pf)
+	if err != nil {
+		c.UI.Output("error fetching envoy stats %v", err, terminal.WithErrorStyle())
+		return 1
+	}
+
+	c.UI.Output(stats)
+	return 0
+
+}
+
+func (c *StatsCommand) getEnvoyStats(pf common.PortForwarder) (string, error) {
+	_, err := pf.Open(c.Ctx)
+	if err != nil {
+		return "", fmt.Errorf("error port forwarding %s", err)
+	}
+	defer pf.Close()
+
+	resp, err := http.Get(fmt.Sprintf("http://localhost:%s/stats", strconv.Itoa(pf.GetLocalPort())))
+	if err != nil {
+		return "", fmt.Errorf("error hitting stats endpoint of envoy %s", err)
+	}
+
+	bodyBytes, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", fmt.Errorf("error reading body of http response %s", err)
+	}
+
+	defer func(Body io.ReadCloser) {
+		_ = Body.Close()
+	}(resp.Body)
+
+	return string(bodyBytes), nil
+}
+
+// setupKubeClient to use for non Helm SDK calls to the Kubernetes API The Helm SDK will use
+// settings.RESTClientGetter for its calls as well, so this will use a consistent method to
+// target the right cluster for both Helm SDK and non Helm SDK calls.
+func (c *StatsCommand) setupKubeClient(settings *helmCLI.EnvSettings) error {
+	if c.kubernetes == nil {
+		restConfig, err := settings.RESTClientGetter().ToRESTConfig()
+		if err != nil {
+			c.UI.Output("Error retrieving Kubernetes authentication: %v", err, terminal.WithErrorStyle())
+			return err
+		}
+		c.kubernetes, err = kubernetes.NewForConfig(restConfig)
+		if err != nil {
+			c.UI.Output("Error initializing Kubernetes client: %v", err, terminal.WithErrorStyle())
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (c *StatsCommand) parseFlags(args []string) error {
+	// Separate positional arguments from keyed arguments.
+	var positional []string
+	for _, arg := range args {
+		if strings.HasPrefix(arg, "-") {
+			break
+		}
+		positional = append(positional, arg)
+	}
+	keyed := args[len(positional):]
+
+	if len(positional) != 1 {
+		return fmt.Errorf("exactly one positional argument is required: <pod-name>")
+	}
+	c.flagPod = positional[0]
+
+	if err := c.set.Parse(keyed); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// Help returns a description of the command and how it is used.
+func (c *StatsCommand) Help() string {
+	c.once.Do(c.init)
+	return c.Synopsis() + "\n\nUsage: consul-k8s proxy stats pod-name -n namespace [flags]\n\n" + c.help
+}
+
+// Synopsis returns a one-line command summary.
+func (c *StatsCommand) Synopsis() string {
+	return "Display Envoy stats for a proxy"
+}

cli/cmd/proxy/stats/command_test.go

@@ -0,0 +1,157 @@
+package stats
+
+import (
+	"bytes"
+	"context"
+	"github.com/hashicorp/consul-k8s/cli/common"
+	"github.com/hashicorp/consul-k8s/cli/common/terminal"
+	"github.com/hashicorp/go-hclog"
+	"github.com/stretchr/testify/require"
+	"io"
+	v1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/kubernetes/fake"
+	"net/http"
+	"os"
+	"strconv"
+	"testing"
+)
+
+func TestFlagParsing(t *testing.T) {
+	cases := map[string]struct {
+		args []string
+		out  int
+	}{
+		"No args, should fail": {
+			args: []string{},
+			out:  1,
+		},
+		"Nonexistent flag passed, -foo bar, should fail": {
+			args: []string{"-foo", "bar"},
+			out:  1,
+		},
+		"Invalid argument passed, -namespace notaname, should fail": {
+			args: []string{"-namespace", "notaname"},
+			out:  1,
+		},
+	}
+
+	for name, tc := range cases {
+		t.Run(name, func(t *testing.T) {
+			c := setupCommand(new(bytes.Buffer))
+			c.kubernetes = fake.NewSimpleClientset()
+			out := c.Run(tc.args)
+			require.Equal(t, tc.out, out)
+		})
+	}
+}
+func setupCommand(buf io.Writer) *StatsCommand {
+	// Log at a test level to standard out.
+	log := hclog.New(&hclog.LoggerOptions{
+		Name:   "test",
+		Level:  hclog.Debug,
+		Output: os.Stdout,
+	})
+
+	// Setup and initialize the command struct
+	command := &StatsCommand{
+		BaseCommand: &common.BaseCommand{
+			Log: log,
+			UI:  terminal.NewUI(context.Background(), buf),
+		},
+	}
+	command.init()
+
+	return command
+}
+
+type MockPortForwarder struct {
+}
+
+func (mpf *MockPortForwarder) Open(ctx context.Context) (string, error) {
+	return "localhost:" + strconv.Itoa(envoyAdminPort), nil
+}
+
+func (mpf *MockPortForwarder) Close() {
+	//noop
+}
+
+func (mpf *MockPortForwarder) GetLocalPort() int {
+	return envoyAdminPort
+}
+
+func TestEnvoyStats(t *testing.T) {
+	cases := map[string]struct {
+		namespace string
+		pods      []v1.Pod
+	}{
+		"Sidecar Pods": {
+			namespace: "default",
+			pods: []v1.Pod{
+				{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      "pod1",
+						Namespace: "default",
+						Labels: map[string]string{
+							"consul.hashicorp.com/connect-inject-status": "injected",
+						},
+					},
+				},
+			},
+		},
+		"Pods in consul namespaces": {
+			namespace: "consul",
+			pods: []v1.Pod{
+				{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      "api-gateway",
+						Namespace: "consul",
+						Labels: map[string]string{
+							"api-gateway.consul.hashicorp.com/managed": "true",
+						},
+					},
+				},
+				{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      "pod1",
+						Namespace: "consul",
+						Labels: map[string]string{
+							"consul.hashicorp.com/connect-inject-status": "injected",
+						},
+					},
+				},
+			},
+		},
+	}
+
+	srv := startHttpServer(envoyAdminPort)
+	for name, tc := range cases {
+		t.Run(name, func(t *testing.T) {
+			c := setupCommand(new(bytes.Buffer))
+			c.kubernetes = fake.NewSimpleClientset(&v1.PodList{Items: tc.pods})
+			c.flagNamespace = tc.namespace
+			for _, pod := range tc.pods {
+				c.flagPod = pod.Name
+				mpf := &MockPortForwarder{}
+				resp, err := c.getEnvoyStats(mpf)
+				require.NoError(t, err)
+				require.Equal(t, resp, "Envoy Stats")
+			}
+		})
+	}
+	srv.Shutdown(context.Background())
+}
+
+func startHttpServer(port int) *http.Server {
+	srv := &http.Server{Addr: ":" + strconv.Itoa(port)}
+
+	http.HandleFunc("/stats", func(w http.ResponseWriter, r *http.Request) {
+		io.WriteString(w, "Envoy Stats")
+	})
+
+	go func() {
+		srv.ListenAndServe()
+	}()
+
+	return srv
+}