scout/advise: first iteration of the src scout advise subcommand (#988)

Author: jasonhawkharris

cmd/src/scout_advise.go

@@ -0,0 +1,120 @@
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"path/filepath"
+
+	"github.com/docker/docker/client"
+	"github.com/sourcegraph/sourcegraph/lib/errors"
+	"github.com/sourcegraph/src-cli/internal/scout/advise"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/tools/clientcmd"
+	"k8s.io/client-go/util/homedir"
+	metricsv "k8s.io/metrics/pkg/client/clientset/versioned"
+)
+
+func init() {
+	cmdUsage := `'src scout advise' is a tool that makes resource allocation recommendations. Based on current usage.
+    Part of the EXPERIMENTAL "src scout" tool.
+    
+    Examples
+        Make recommendations for all pods in a kubernetes deployment of Sourcegraph.
+        $ src scout advise
+        
+        Make recommendations for all containers in a Docker deployment of Sourcegraph.
+        $ src scout advise
+        
+        Make recommendations for specific pod:
+        $ src scout advise --pod <podname>
+
+        Make recommendations for specific container:
+        $ src scout advise --container <containername>
+
+        Add namespace if using namespace in a Kubernetes cluster
+        $ src scout advise --namespace <namespace>
+    `
+
+	flagSet := flag.NewFlagSet("advise", flag.ExitOnError)
+	usage := func() {
+		fmt.Fprintf(flag.CommandLine.Output(), "Usage of 'src scout %s':\n", flagSet.Name())
+		flagSet.PrintDefaults()
+		fmt.Println(cmdUsage)
+	}
+
+	var (
+		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")
+	)
+
+	if home := homedir.HomeDir(); home != "" {
+		kubeConfig = flagSet.String(
+			"kubeconfig",
+			filepath.Join(home, ".kube", "config"),
+			"(optional) absolute path to the kubeconfig file",
+		)
+	} else {
+		kubeConfig = flagSet.String("kubeconfig", "", "absolute path to the kubeconfig file")
+	}
+
+	handler := func(args []string) error {
+		if err := flagSet.Parse(args); err != nil {
+			return err
+		}
+
+		config, err := clientcmd.BuildConfigFromFlags("", *kubeConfig)
+		if err != nil {
+			return errors.Wrap(err, "failed to load .kube config: ")
+		}
+
+		clientSet, err := kubernetes.NewForConfig(config)
+		if err != nil {
+			return errors.Wrap(err, "failed to initiate kubernetes client: ")
+		}
+
+		metricsClient, err := metricsv.NewForConfig(config)
+		if err != nil {
+			return errors.Wrap(err, "failed to initiate metrics client")
+		}
+
+		var options []advise.Option
+
+		if *namespace != "" {
+			options = append(options, advise.WithNamespace(*namespace))
+		}
+		if *pod != "" {
+			options = append(options, advise.WithPod(*pod))
+		}
+		if *container != "" || *docker {
+			if *container != "" {
+				options = append(options, advise.WithContainer(*container))
+			}
+
+			dockerClient, err := client.NewClientWithOpts(client.FromEnv)
+			if err != nil {
+				return errors.Wrap(err, "error creating docker client: ")
+			}
+
+			return advise.Docker(context.Background(), *dockerClient, options...)
+		}
+
+		return advise.K8s(
+			context.Background(),
+			clientSet,
+			metricsClient,
+			config,
+			options...,
+		)
+	}
+
+	scoutCommands = append(scoutCommands, &command{
+		flagSet:   flagSet,
+		handler:   handler,
+		usageFunc: usage,
+	})
+
+}

internal/scout/advise/advise.go

@@ -0,0 +1,30 @@
+package advise
+
+import "github.com/sourcegraph/src-cli/internal/scout"
+
+type Option = func(config *scout.Config)
+
+const (
+	OVER_100 = "\t%s %s: Your %s usage is over 100%% (%.2f%%). Add more %s."
+	OVER_80  = "\t%s %s: Your %s usage is over 80%% (%.2f%%). Consider raising limits."
+	OVER_40  = "\t%s %s: Your %s usage is under 80%% (%.2f%%). Keep %s allocation the same."
+	UNDER_40 = "\t%s %s: Your %s usage is under 40%% (%.2f%%). Consider lowering limits."
+)
+
+func WithNamespace(namespace string) Option {
+	return func(config *scout.Config) {
+		config.Namespace = namespace
+	}
+}
+
+func WithPod(podname string) Option {
+	return func(config *scout.Config) {
+		config.Pod = podname
+	}
+}
+
+func WithContainer(containerName string) Option {
+	return func(config *scout.Config) {
+		config.Container = containerName
+	}
+}

internal/scout/advise/docker.go

@@ -0,0 +1,40 @@
+package advise
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/client"
+	"github.com/sourcegraph/sourcegraph/lib/errors"
+	"github.com/sourcegraph/src-cli/internal/scout"
+)
+
+func Docker(ctx context.Context, client client.Client, opts ...Option) error {
+	cfg := &scout.Config{
+		Namespace:    "default",
+		Docker:       true,
+		Pod:          "",
+		Container:    "",
+		Spy:          false,
+		DockerClient: &client,
+	}
+
+	for _, opt := range opts {
+		opt(cfg)
+	}
+
+	containers, err := client.ContainerList(ctx, types.ContainerListOptions{})
+	if err != nil {
+		return errors.Wrap(err, "could not get list of containers")
+	}
+
+	PrintContainers(containers)
+	return nil
+}
+
+func PrintContainers(containers []types.Container) {
+	for _, c := range containers {
+		fmt.Println(c.Image)
+	}
+}

internal/scout/advise/k8s.go

@@ -0,0 +1,164 @@
+package advise
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/sourcegraph/sourcegraph/lib/errors"
+	"github.com/sourcegraph/src-cli/internal/scout"
+	"github.com/sourcegraph/src-cli/internal/scout/kube"
+	v1 "k8s.io/api/core/v1"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/rest"
+	metricsv "k8s.io/metrics/pkg/client/clientset/versioned"
+)
+
+func K8s(
+	ctx context.Context,
+	k8sClient *kubernetes.Clientset,
+	metricsClient *metricsv.Clientset,
+	restConfig *rest.Config,
+	opts ...Option,
+) error {
+	cfg := &scout.Config{
+		Namespace:     "default",
+		Pod:           "",
+		Container:     "",
+		Spy:           false,
+		Docker:        false,
+		RestConfig:    restConfig,
+		K8sClient:     k8sClient,
+		DockerClient:  nil,
+		MetricsClient: metricsClient,
+	}
+
+	for _, opt := range opts {
+		opt(cfg)
+	}
+
+	pods, err := kube.GetPods(ctx, cfg)
+	if err != nil {
+		return errors.Wrap(err, "could not get list of pods")
+	}
+
+	if cfg.Pod != "" {
+		pod, err := kube.GetPod(cfg.Pod, pods)
+		if err != nil {
+			return errors.Wrap(err, "could not get pod")
+		}
+
+		err = Advise(ctx, cfg, pod)
+		if err != nil {
+			return errors.Wrap(err, "could not advise")
+		}
+		return nil
+	}
+
+	for _, pod := range pods {
+		err = Advise(ctx, cfg, pod)
+		if err != nil {
+			return errors.Wrap(err, "could not advise")
+		}
+	}
+
+	return nil
+}
+
+func Advise(ctx context.Context, cfg *scout.Config, pod v1.Pod) error {
+	var advice []string
+	usageMetrics, err := getUsageMetrics(ctx, cfg, pod)
+	if err != nil {
+		return errors.Wrap(err, "could not get usage metrics")
+	}
+
+	for _, metrics := range usageMetrics {
+		cpuAdvice := checkUsage(metrics.CpuUsage, "CPU", metrics.ContainerName, pod.Name)
+		advice = append(advice, cpuAdvice)
+
+		memoryAdvice := checkUsage(metrics.MemoryUsage, "memory", metrics.ContainerName, pod.Name)
+		advice = append(advice, memoryAdvice)
+
+		if metrics.Storage != nil {
+			storageAdvice := checkUsage(metrics.StorageUsage, "storage", metrics.ContainerName, pod.Name)
+			advice = append(advice, storageAdvice)
+		}
+
+		fmt.Println(scout.EmojiFingerPointRight, pod.Name)
+		for _, msg := range advice {
+			fmt.Println(msg)
+		}
+	}
+
+	return nil
+}
+
+func getUsageMetrics(ctx context.Context, cfg *scout.Config, pod v1.Pod) ([]scout.UsageStats, error) {
+	var usages []scout.UsageStats
+	var usage scout.UsageStats
+	podMetrics, err := kube.GetPodMetrics(ctx, cfg, pod)
+	if err != nil {
+		return usages, errors.Wrap(err, "while attempting to fetch pod metrics")
+	}
+
+	containerMetrics := &scout.ContainerMetrics{
+		PodName: cfg.Pod,
+		Limits:  map[string]scout.Resources{},
+	}
+
+	if err = kube.AddLimits(ctx, cfg, &pod, containerMetrics); err != nil {
+		return usages, errors.Wrap(err, "failed to get get container metrics")
+	}
+
+	for _, container := range podMetrics.Containers {
+		usage, err = kube.GetUsage(ctx, cfg, *containerMetrics, pod, container)
+		if err != nil {
+			return usages, errors.Wrapf(err, "could not compile usages data for row: %s\n", container.Name)
+		}
+		usages = append(usages, usage)
+	}
+
+	return usages, nil
+}
+
+func checkUsage(usage float64, resourceType, container, pod string) string {
+	var message string
+
+	switch {
+	case usage >= 100:
+		message = fmt.Sprintf(
+			OVER_100,
+			scout.FlashingLightEmoji,
+			container,
+			resourceType,
+			usage,
+			resourceType,
+		)
+	case usage >= 80 && usage < 100:
+		message = fmt.Sprintf(
+			OVER_80,
+			scout.WarningSign,
+			container,
+			resourceType,
+			usage,
+		)
+	case usage >= 40 && usage < 80:
+		message = fmt.Sprintf(
+			OVER_40,
+			scout.SuccessEmoji,
+			container,
+			resourceType,
+			usage,
+			resourceType,
+		)
+	default:
+		message = fmt.Sprintf(
+			UNDER_40,
+			scout.WarningSign,
+			container,
+			resourceType,
+			usage,
+		)
+	}
+
+	return message
+}

internal/scout/constants.go

@@ -0,0 +1,9 @@
+package scout
+
+const (
+	ABillion              float64 = 1_000_000_000
+	EmojiFingerPointRight         = "👉"
+	FlashingLightEmoji            = "🚨"
+	SuccessEmoji                  = "✅"
+	WarningSign                   = "⚠️ " // why does this need an extra space to align?!?!
+)

internal/scout/helpers.go

@@ -0,0 +1,24 @@
+package scout
+
+// contains checks if a string slice contains a given value.
+func Contains(slice []string, value string) bool {
+	for _, v := range slice {
+		if v == value {
+			return true
+		}
+	}
+	return false
+}
+
+// getPercentage calculates the percentage of x in relation to y.
+func GetPercentage(x, y float64) float64 {
+	if x == 0 {
+		return 0
+	}
+
+	if y == 0 {
+		return 0
+	}
+
+	return x * 100 / y
+}