scout/usage: add --container flag to src scout usage (#986)

Author: jasonhawkharris

cmd/src/scout_usage.go

@@ -29,6 +29,9 @@ func init() {
         Check usage for specific pod
         $ src scout usage --pod <podname>
 
+        Check usage for specific container (docker only)
+        $ src scout usage --container <containername>
+
         Add namespace if using namespace in a Kubernetes cluster
         $ src scout usage --namespace <namespace>
         
@@ -47,6 +50,7 @@ func init() {
 		kubeConfig *string
 		namespace  = flagSet.String("namespace", "", "(optional) specify the kubernetes namespace to use")
 		pod        = flagSet.String("pod", "", "(optional) specify a single pod")
+		container  = flagSet.String("container", "", "(optional) specify a single container")
 		docker     = flagSet.Bool("docker", false, "(optional) using docker deployment")
 		spy        = flagSet.Bool("spy", false, "(optional) see resource usage in real time")
 	)
@@ -92,14 +96,17 @@ func init() {
 		if *pod != "" {
 			options = append(options, usage.WithPod(*pod))
 		}
+		if *container != "" || *docker {
+			if *container != "" {
+				options = append(options, usage.WithContainer(*container))
+			}
 
-		if *docker {
 			dockerClient, err := client.NewClientWithOpts(client.FromEnv)
 			if err != nil {
 				return errors.Wrap(err, "error creating docker client: ")
 			}
 
-			return usage.Docker(context.Background(), *dockerClient)
+			return usage.Docker(context.Background(), *dockerClient, options...)
 		}
 
 		return usage.K8s(

internal/scout/usage/docker.go

@@ -4,8 +4,10 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"os"
 
 	"github.com/charmbracelet/bubbles/table"
+	"github.com/charmbracelet/lipgloss"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/client"
 	"github.com/sourcegraph/sourcegraph/lib/errors"
@@ -51,34 +53,58 @@ func renderDockerUsageTable(ctx context.Context, cfg *Config, containers []types
 			return errors.Wrap(err, "failed to get container info")
 		}
 
-		stats, err := cfg.dockerClient.ContainerStats(ctx, container.ID, false)
-		if err != nil {
-			return errors.Wrap(err, "could not get container stats")
-		}
-		defer stats.Body.Close()
-
-		var usage types.StatsJSON
-		if err := json.NewDecoder(stats.Body).Decode(&usage); err != nil {
-			return errors.Wrap(err, "could not decode container stats")
+		if cfg.container != "" {
+			if containerInfo.Name == cfg.container {
+				row := makeDockerUsageRow(ctx, cfg, containerInfo)
+				rows = append(rows, row)
+				break
+			} else {
+				continue
+			}
 		}
 
-		row := makeDockerUsageRow(usage, containerInfo)
+		row := makeDockerUsageRow(ctx, cfg, containerInfo)
 		rows = append(rows, row)
 	}
 
+	if len(rows) == 0 {
+		msg := lipgloss.NewStyle().Foreground(lipgloss.Color("#FFA500"))
+		if cfg.container == "" {
+			fmt.Println(msg.Render(`No docker containers are running.`))
+			os.Exit(1)
+		}
+		fmt.Println(msg.Render(
+			fmt.Sprintf(`No container with name '%s' running.`, cfg.container),
+		))
+		os.Exit(1)
+	}
+
 	style.ResourceTable(columns, rows)
 	return nil
 }
 
 // makeDockerUsageRow generates a table row displaying CPU and memory usage for a Docker container.
-func makeDockerUsageRow(containerUsage types.StatsJSON, containerInfo types.ContainerJSON) table.Row {
-	cpuCores := float64(containerInfo.HostConfig.NanoCPUs)
-	memory := float64(containerInfo.HostConfig.Memory)
-	cpuUsage := float64(containerUsage.CPUStats.CPUUsage.TotalUsage)
-	memoryUsage := float64(containerUsage.MemoryStats.Usage)
+func makeDockerUsageRow(ctx context.Context, cfg *Config, container types.ContainerJSON) table.Row {
+	stats, err := cfg.dockerClient.ContainerStats(ctx, container.ID, false)
+	if err != nil {
+		errors.Wrap(err, "could not get container stats")
+		os.Exit(1)
+	}
+	defer func() { _ = stats.Body.Close() }()
+
+	var usage types.StatsJSON
+	if err := json.NewDecoder(stats.Body).Decode(&usage); err != nil {
+		errors.Wrap(err, "could not get container stats")
+		os.Exit(1)
+	}
+
+	cpuCores := float64(container.HostConfig.NanoCPUs)
+	memory := float64(container.HostConfig.Memory)
+	cpuUsage := float64(usage.CPUStats.CPUUsage.TotalUsage)
+	memoryUsage := float64(usage.MemoryStats.Usage)
 
 	return table.Row{
-		containerInfo.Name,
+		container.Name,
 		fmt.Sprintf("%.2f", cpuCores/1_000_000_000),
 		fmt.Sprintf("%.2f%%", getPercentage(cpuUsage, cpuCores)),
 		fmt.Sprintf("%.2fG", memory/1_000_000_000),