Exported services CLI and docs

.changelog/20331.txt

@@ -0,0 +1,3 @@
+```release-note:feature
+cli: Adds new command `exported-services` to list all services exported and their consumers. Refer to the [CLI docs](https://developer.hashicorp.com/consul/commands/exported-services) for more information.
+```

command/exportedservices/exported_services.go

@@ -0,0 +1,154 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: BUSL-1.1
+
+package exportedservices
+
+import (
+	"encoding/json"
+	"flag"
+	"fmt"
+	"strings"
+
+	"github.com/mitchellh/cli"
+
+	"github.com/hashicorp/consul/api"
+	"github.com/hashicorp/consul/command/flags"
+	"github.com/ryanuber/columnize"
+)
+
+const (
+	PrettyFormat string = "pretty"
+	JSONFormat   string = "json"
+)
+
+func getSupportedFormats() []string {
+	return []string{PrettyFormat, JSONFormat}
+}
+
+func formatIsValid(f string) bool {
+	return f == PrettyFormat || f == JSONFormat
+}
+
+func New(ui cli.Ui) *cmd {
+	c := &cmd{UI: ui}
+	c.init()
+	return c
+}
+
+type cmd struct {
+	UI    cli.Ui
+	flags *flag.FlagSet
+	http  *flags.HTTPFlags
+	help  string
+
+	format string
+}
+
+func (c *cmd) init() {
+	c.flags = flag.NewFlagSet("", flag.ContinueOnError)
+
+	c.flags.StringVar(
+		&c.format,
+		"format",
+		PrettyFormat,
+		fmt.Sprintf("Output format {%s} (default: %s)", strings.Join(getSupportedFormats(), "|"), PrettyFormat),
+	)
+
+	c.http = &flags.HTTPFlags{}
+	flags.Merge(c.flags, c.http.ClientFlags())
+	flags.Merge(c.flags, c.http.ServerFlags())
+	flags.Merge(c.flags, c.http.PartitionFlag())
+	c.help = flags.Usage(help, c.flags)
+}
+
+func (c *cmd) Run(args []string) int {
+	if err := c.flags.Parse(args); err != nil {
+		return 1
+	}
+
+	if !formatIsValid(c.format) {
+		c.UI.Error(fmt.Sprintf("Invalid format, valid formats are {%s}", strings.Join(getSupportedFormats(), "|")))
+		return 1
+	}
+
+	client, err := c.http.APIClient()
+	if err != nil {
+		c.UI.Error(fmt.Sprintf("Error connect to Consul agent: %s", err))
+		return 1
+	}
+
+	exportedServices, _, err := client.ExportedServices(nil)
+	if err != nil {
+		c.UI.Error(fmt.Sprintf("Error reading exported services: %v", err))
+		return 1
+	}
+
+	if len(exportedServices) == 0 {
+		c.UI.Info("No exported services found")
+		return 0
+	}
+
+	if c.format == JSONFormat {
+		output, err := json.MarshalIndent(exportedServices, "", "    ")
+		if err != nil {
+			c.UI.Error(fmt.Sprintf("Error marshalling JSON: %s", err))
+			return 1
+		}
+		c.UI.Output(string(output))
+		return 0
+	}
+
+	c.UI.Output(formatExportedServices(exportedServices))
+
+	return 0
+}
+
+func formatExportedServices(services []api.ResolvedExportedService) string {
+	result := make([]string, 0, len(services)+1)
+
+	if services[0].Partition != "" {
+		result = append(result, "Service\x1fPartition\x1fNamespace\x1fConsumer")
+	} else {
+		result = append(result, "Service\x1fConsumer")
+	}
+
+	for _, expService := range services {
+		service := ""
+		if expService.Partition != "" {
+			service = fmt.Sprintf("%s\x1f%s\x1f%s", expService.Service, expService.Partition, expService.Namespace)
+		} else {
+			service = expService.Service
+		}
+
+		for _, peer := range expService.Consumers.Peers {
+			result = append(result, fmt.Sprintf("%s\x1fPeer: %s", service, peer))
+		}
+		for _, partition := range expService.Consumers.Partitions {
+			result = append(result, fmt.Sprintf("%s\x1fPartition: %s", service, partition))
+		}
+
+	}
+
+	return columnize.Format(result, &columnize.Config{Delim: string([]byte{0x1f})})
+}
+
+func (c *cmd) Synopsis() string {
+	return synopsis
+}
+
+func (c *cmd) Help() string {
+	return flags.Usage(c.help, nil)
+}
+
+const (
+	synopsis = "Lists exported services"
+	help     = `
+Usage: consul exported-services [options]
+
+  Lists all the exported services and their consumers. Wildcards and sameness groups(Enterprise) are expanded.
+
+  Example:
+
+    $ consul exported-services
+`
+)

command/exportedservices/exported_services_test.go

@@ -0,0 +1,178 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: BUSL-1.1
+
+package exportedservices
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/hashicorp/consul/agent"
+	"github.com/hashicorp/consul/api"
+	"github.com/mitchellh/cli"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestExportedServices_noTabs(t *testing.T) {
+	t.Parallel()
+
+	require.NotContains(t, New(cli.NewMockUi()).Help(), "\t")
+}
+
+func TestExportedServices_Error(t *testing.T) {
+	if testing.Short() {
+		t.Skip("too slow for testing.Short")
+	}
+
+	t.Parallel()
+
+	a := agent.NewTestAgent(t, ``)
+	defer a.Shutdown()
+
+	t.Run("No exported services", func(t *testing.T) {
+		ui := cli.NewMockUi()
+		cmd := New(ui)
+
+		args := []string{
+			"-http-addr=" + a.HTTPAddr(),
+		}
+
+		code := cmd.Run(args)
+		require.Equal(t, 0, code)
+
+		output := ui.OutputWriter.String()
+		require.Equal(t, "No exported services found\n", output)
+	})
+
+	t.Run("invalid format", func(t *testing.T) {
+		ui := cli.NewMockUi()
+		cmd := New(ui)
+
+		args := []string{
+			"-http-addr=" + a.HTTPAddr(),
+			"-format=toml",
+		}
+
+		code := cmd.Run(args)
+		require.Equal(t, 1, code, "exited successfully when it should have failed")
+		output := ui.ErrorWriter.String()
+		require.Contains(t, output, "Invalid format")
+	})
+}
+
+func TestExportedServices_Pretty(t *testing.T) {
+	if testing.Short() {
+		t.Skip("too slow for testing.Short")
+	}
+
+	t.Parallel()
+
+	a := agent.NewTestAgent(t, ``)
+	defer a.Shutdown()
+	client := a.Client()
+
+	ui := cli.NewMockUi()
+	c := New(ui)
+
+	set, _, err := client.ConfigEntries().Set(&api.ExportedServicesConfigEntry{
+		Name: "default",
+		Services: []api.ExportedService{
+			{
+				Name: "db",
+				Consumers: []api.ServiceConsumer{
+					{
+						Peer: "east",
+					},
+					{
+						Peer: "west",
+					},
+				},
+			},
+			{
+				Name: "web",
+				Consumers: []api.ServiceConsumer{
+					{
+						Peer: "east",
+					},
+				},
+			},
+		},
+	}, nil)
+	require.NoError(t, err)
+	require.True(t, set)
+
+	args := []string{
+		"-http-addr=" + a.HTTPAddr(),
+	}
+
+	code := c.Run(args)
+	require.Equal(t, 0, code)
+
+	output := ui.OutputWriter.String()
+
+	// Spot check some fields and values
+	require.Contains(t, output, "db")
+	require.Contains(t, output, "web")
+}
+
+func TestExportedServices_JSON(t *testing.T) {
+	if testing.Short() {
+		t.Skip("too slow for testing.Short")
+	}
+
+	t.Parallel()
+
+	a := agent.NewTestAgent(t, ``)
+	defer a.Shutdown()
+	client := a.Client()
+
+	ui := cli.NewMockUi()
+	c := New(ui)
+
+	set, _, err := client.ConfigEntries().Set(&api.ExportedServicesConfigEntry{
+		Name: "default",
+		Services: []api.ExportedService{
+			{
+				Name: "db",
+				Consumers: []api.ServiceConsumer{
+					{
+						Peer: "east",
+					},
+					{
+						Peer: "west",
+					},
+				},
+			},
+			{
+				Name: "web",
+				Consumers: []api.ServiceConsumer{
+					{
+						Peer: "east",
+					},
+				},
+			},
+		},
+	}, nil)
+	require.NoError(t, err)
+	require.True(t, set)
+
+	args := []string{
+		"-http-addr=" + a.HTTPAddr(),
+		"-format=json",
+	}
+
+	code := c.Run(args)
+	require.Equal(t, 0, code)
+
+	var resp []api.ResolvedExportedService
+
+	err = json.Unmarshal(ui.OutputWriter.Bytes(), &resp)
+	require.NoError(t, err)
+
+	require.Equal(t, 2, len(resp))
+	require.Equal(t, "db", resp[0].Service)
+	require.Equal(t, "web", resp[1].Service)
+	require.Equal(t, []string{"east", "west"}, resp[0].Consumers.Peers)
+	require.Equal(t, []string{"east"}, resp[1].Consumers.Peers)
+}

command/registry.go

@@ -69,6 +69,7 @@ import (
 	"github.com/hashicorp/consul/command/debug"
 	"github.com/hashicorp/consul/command/event"
 	"github.com/hashicorp/consul/command/exec"
+	exportedservices "github.com/hashicorp/consul/command/exportedservices"
 	"github.com/hashicorp/consul/command/forceleave"
 	"github.com/hashicorp/consul/command/info"
 	"github.com/hashicorp/consul/command/intention"
@@ -212,6 +213,7 @@ func RegisteredCommands(ui cli.Ui) map[string]mcli.CommandFactory {
 		entry{"debug", func(ui cli.Ui) (cli.Command, error) { return debug.New(ui), nil }},
 		entry{"event", func(ui cli.Ui) (cli.Command, error) { return event.New(ui), nil }},
 		entry{"exec", func(ui cli.Ui) (cli.Command, error) { return exec.New(ui, MakeShutdownCh()), nil }},
+		entry{"exported-services", func(ui cli.Ui) (cli.Command, error) { return exportedservices.New(ui), nil }},
 		entry{"force-leave", func(ui cli.Ui) (cli.Command, error) { return forceleave.New(ui), nil }},
 		entry{"info", func(ui cli.Ui) (cli.Command, error) { return info.New(ui), nil }},
 		entry{"intention", func(ui cli.Ui) (cli.Command, error) { return intention.New(), nil }},