feat(internal): Introduce 'metrics' command for instances

Signed-off-by: Cezar Craciunoiu <cezar.craciunoiu@unikraft.io>

internal/cli/kraft/cloud/instance/instance.go

@@ -17,6 +17,7 @@ import (
 	"kraftkit.sh/internal/cli/kraft/cloud/instance/get"
 	"kraftkit.sh/internal/cli/kraft/cloud/instance/list"
 	"kraftkit.sh/internal/cli/kraft/cloud/instance/logs"
+	"kraftkit.sh/internal/cli/kraft/cloud/instance/metrics"
 	"kraftkit.sh/internal/cli/kraft/cloud/instance/remove"
 	"kraftkit.sh/internal/cli/kraft/cloud/instance/start"
 	"kraftkit.sh/internal/cli/kraft/cloud/instance/stop"
@@ -42,6 +43,7 @@ func NewCmd() *cobra.Command {
 	cmd.AddCommand(create.NewCmd())
 	cmd.AddCommand(list.NewCmd())
 	cmd.AddCommand(logs.NewCmd())
+	cmd.AddCommand(metrics.NewCmd())
 	cmd.AddCommand(remove.NewCmd())
 	cmd.AddCommand(start.NewCmd())
 	cmd.AddCommand(get.NewCmd())

internal/cli/kraft/cloud/instance/metrics/metrics.go

@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: BSD-3-Clause
+// Copyright (c) 2024, Unikraft GmbH and The KraftKit Authors.
+// Licensed under the BSD-3-Clause License (the "License").
+// You may not use this file except in compliance with the License.
+
+package metrics
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/MakeNowJust/heredoc"
+	"github.com/spf13/cobra"
+
+	kraftcloud "sdk.kraft.cloud"
+
+	"kraftkit.sh/cmdfactory"
+	"kraftkit.sh/config"
+	"kraftkit.sh/internal/cli/kraft/cloud/utils"
+)
+
+type MetricsOptions struct {
+	Auth   *config.AuthConfig    `noattribute:"true"`
+	Client kraftcloud.KraftCloud `noattribute:"true"`
+	Metro  string                `noattribute:"true"`
+	Token  string                `noattribute:"true"`
+	Output string                `long:"output" short:"o" usage:"Set output format. Options: table,yaml,json,list" default:"list"`
+}
+
+func NewCmd() *cobra.Command {
+	cmd, err := cmdfactory.New(&MetricsOptions{}, cobra.Command{
+		Short:   "Return metrics for instances",
+		Use:     "metrics [FLAGS] [UUID|NAME [UUID|NAME]...]",
+		Aliases: []string{"metric", "m", "meter"},
+		Args:    cobra.MinimumNArgs(1),
+		Example: heredoc.Doc(`
+			# Return metrics for an instance by UUID
+			$ kraft cloud instance metrics fd1684ea-7970-4994-92d6-61dcc7905f2b
+
+			# Return metrics for an instance by name
+			$ kraft cloud instance metrics my-instance-431342
+		`),
+		Annotations: map[string]string{
+			cmdfactory.AnnotationHelpGroup: "kraftcloud-instance",
+		},
+	})
+	if err != nil {
+		panic(err)
+	}
+
+	return cmd
+}
+
+func (opts *MetricsOptions) Pre(cmd *cobra.Command, _ []string) error {
+	err := utils.PopulateMetroToken(cmd, &opts.Metro, &opts.Token)
+	if err != nil {
+		return fmt.Errorf("could not populate metro and token: %w", err)
+	}
+
+	if !utils.IsValidOutputFormat(opts.Output) {
+		return fmt.Errorf("invalid output format: %s", opts.Output)
+	}
+
+	return nil
+}
+
+func (opts *MetricsOptions) Run(ctx context.Context, args []string) error {
+	auth, err := config.GetKraftCloudAuthConfig(ctx, opts.Token)
+	if err != nil {
+		return fmt.Errorf("could not retrieve credentials: %w", err)
+	}
+
+	client := kraftcloud.NewInstancesClient(
+		kraftcloud.WithToken(config.GetKraftCloudTokenAuthConfig(*auth)),
+	)
+
+	resp, err := client.WithMetro(opts.Metro).Metrics(ctx, args...)
+	if err != nil {
+		return fmt.Errorf("could not get instance %s: %w", args, err)
+	}
+
+	return utils.PrintMetrics(ctx, opts.Output, *resp)
+}

internal/cli/kraft/cloud/utils/print.go

@@ -1070,6 +1070,109 @@ func PrintCertificates(ctx context.Context, format string, resp kcclient.Service
 	return table.Render(iostreams.G(ctx).Out)
 }
 
+// PrintMetrics pretty-prints the provided set of instances metrics or returns
+// an error if unable to send to stdout via the provided context.
+func PrintMetrics(ctx context.Context, format string, resp kcclient.ServiceResponse[kcinstances.MetricsResponseItem]) error {
+	if format == "raw" {
+		printRaw(ctx, resp)
+		return nil
+	}
+
+	metrics, err := resp.AllOrErr()
+	if err != nil {
+		return err
+	}
+
+	if err := iostreams.G(ctx).StartPager(); err != nil {
+		log.G(ctx).Errorf("error starting pager: %v", err)
+	}
+
+	defer iostreams.G(ctx).StopPager()
+
+	cs := iostreams.G(ctx).ColorScheme()
+	table, err := tableprinter.NewTablePrinter(ctx,
+		tableprinter.WithMaxWidth(iostreams.G(ctx).TerminalWidth()),
+		tableprinter.WithOutputFormatFromString(format),
+	)
+	if err != nil {
+		return err
+	}
+
+	// Header row
+	if format != "table" {
+		table.AddField("UUID", cs.Bold)
+	}
+	table.AddField("NAME", cs.Bold)
+	table.AddField("RSS", cs.Bold)
+	table.AddField("CPU TIME", cs.Bold)
+	if format != "table" {
+		table.AddField("RX SIZE", cs.Bold)
+		table.AddField("RX PACKETS", cs.Bold)
+		table.AddField("TX SIZE", cs.Bold)
+		table.AddField("TX PACKETS", cs.Bold)
+		table.AddField("CONNECTIONS", cs.Bold)
+		table.AddField("REQUESTS", cs.Bold)
+		table.AddField("QUEUED", cs.Bold)
+	}
+	table.AddField("TOTAL", cs.Bold)
+	table.EndRow()
+
+	if config.G[config.KraftKit](ctx).NoColor {
+		instanceStateColor = instanceStateColorNil
+	}
+
+	for _, metric := range metrics {
+		if metric.Message != "" {
+			// Header row
+			if format != "table" {
+				table.AddField(metric.UUID, nil)
+			}
+			table.AddField(metric.Name, nil)
+			table.AddField("", nil) // RSS
+			table.AddField("", nil) // CPU TIME
+			if format != "table" {
+				table.AddField("", nil)     // RX SIZE
+				table.AddField("", nil)     // RX PACKETS
+				table.AddField("", nil)     // TX SIZE
+				table.AddField("", nil)     // TX PACKETS
+				table.AddField("", nil)     // CONNECTIONS
+				table.AddField("", nil)     // REQUESTS
+				table.AddField("", cs.Bold) // QUEUED
+			}
+			table.AddField("", cs.Bold) // TOTAL
+			table.EndRow()
+
+			continue
+		}
+		if format != "table" {
+			table.AddField(metric.UUID, nil)
+		}
+
+		table.AddField(metric.Name, nil)
+		table.AddField(humanize.IBytes(metric.RSS), nil)
+
+		duration, err := time.ParseDuration(fmt.Sprintf("%dms", metric.CPUTimeMs))
+		if err != nil {
+			return fmt.Errorf("could not parse CPU time for '%s': %w", metric.UUID, err)
+		}
+		table.AddField(duration.String(), nil)
+
+		if format != "table" {
+			table.AddField(humanize.IBytes(metric.RxBytes), nil)
+			table.AddField(fmt.Sprintf("%d", metric.RxPackets), nil)
+			table.AddField(humanize.IBytes(metric.TxBytes), nil)
+			table.AddField(fmt.Sprintf("%d", metric.TxPackets), nil)
+			table.AddField(fmt.Sprintf("%d", metric.Connections), nil)
+			table.AddField(fmt.Sprintf("%d", metric.Requests), nil)
+			table.AddField(fmt.Sprintf("%d", metric.Queued), nil)
+		}
+		table.AddField(fmt.Sprintf("%d", metric.Total), nil)
+		table.EndRow()
+	}
+
+	return table.Render(iostreams.G(ctx).Out)
+}
+
 // PrettyPrintInstance outputs a single instance and information about it.
 func PrettyPrintInstance(ctx context.Context, instance kcinstances.GetResponseItem, service *kcservices.GetResponseItem, autoStart bool) {
 	out := iostreams.G(ctx).Out