Add memstat flag

changelogs/unreleased/2127-GuessWhoSamFoo

@@ -0,0 +1 @@
+Added memstats flag

internal/commands/dash.go

@@ -99,6 +99,9 @@ func newOctantCmd(version string, gitCommit string, buildTime string) *cobra.Com
 				if viper.GetBool("enable-opencensus") {
 					options = append(options, dash.WithOpenCensus())
 				}
+				if file := viper.GetString("memstats"); file != "" {
+					options = append(options, dash.WithMemStats())
+				}
 
 				klogVerbosity := viper.GetString("klog-verbosity")
 				var klogOpts []string
@@ -171,6 +174,8 @@ func newOctantCmd(version string, gitCommit string, buildTime string) *cobra.Com
 	octantCmd.Flags().StringP("proxy-frontend", "", "", "url to send frontend request to [DEV]")
 	octantCmd.Flags().String("ui-url", "", "dashboard url [DEV]")
 	octantCmd.Flags().String("browser-path", "", "the browser path to open the browser on")
+	octantCmd.Flags().String("memstats", "", "log memory usage to this file")
+	octantCmd.Flags().String("meminterval", "100ms", "interval to poll memory usage (requires --memstats), valid time units are \"ns\", \"us\" (or \"µs\"), \"ms\", \"s\", \"m\", \"h\".")
 
 	return octantCmd
 }

pkg/dash/dash.go

@@ -13,6 +13,7 @@ import (
 	"net/http"
 	"os"
 	"path/filepath"
+	"runtime"
 	"strings"
 	"time"
 
@@ -53,6 +54,7 @@ import (
 
 type Options struct {
 	EnableOpenCensus       bool
+	EnableMemStats         bool
 	DisableClusterOverview bool
 	KubeConfig             string
 	Namespace              string
@@ -82,6 +84,15 @@ func WithOpenCensus() RunnerOption {
 	}
 }
 
+func WithMemStats() RunnerOption {
+	return RunnerOption{
+		kubeConfigOption: kubeconfig.Noop(),
+		nonClusterOption: func(o *Options) {
+			o.EnableMemStats = true
+		},
+	}
+}
+
 func WithoutClusterOverview() RunnerOption {
 	return RunnerOption{
 		kubeConfigOption: kubeconfig.Noop(),
@@ -352,6 +363,14 @@ func (r *Runner) initAPI(ctx context.Context, logger log.Logger, opts ...RunnerO
 		}
 	}
 
+	fmt.Println(options.EnableMemStats)
+	if options.EnableMemStats {
+		if err := memStats(); err != nil {
+			logger.Infof("Enable MemStat")
+			return nil, nil, fmt.Errorf("enabling memstat: %w", err)
+		}
+	}
+
 	nsClient, err := clusterClient.NamespaceClient()
 	if err != nil {
 		return nil, nil, fmt.Errorf("failed to create namespace client: %w", err)
@@ -704,6 +723,38 @@ func enableOpenCensus() error {
 	return nil
 }
 
+func memStats() error {
+	memstats := viper.GetString("memstats")
+	if memstats != "" {
+		interval, err := time.ParseDuration(viper.GetString("meminterval"))
+		if err != nil {
+			interval, _ = time.ParseDuration("100ms")
+		}
+
+		fileMemStats, err := os.Create(memstats)
+		if err != nil {
+			return err
+		}
+
+		fileMemStats.WriteString("# Time\tHeapSys\tHeapAlloc\tHeapIdle\tHeapReleased\n")
+		go func() {
+			var stats runtime.MemStats
+			start := time.Now().UnixNano()
+			for {
+				runtime.ReadMemStats(&stats)
+				if fileMemStats != nil {
+					fileMemStats.WriteString(fmt.Sprintf("%d\t%d\t%d\t%d\t%d\n",
+						(time.Now().UnixNano()-start)/1000000, stats.HeapSys, stats.HeapAlloc, stats.HeapIdle, stats.HeapReleased))
+					time.Sleep(interval)
+				} else {
+					break
+				}
+			}
+		}()
+	}
+	return nil
+}
+
 // ValidateKubeConfig returns a valid file list of kube config(s)
 func ValidateKubeConfig(logger log.Logger, kubeConfig string, fs afero.Fs) (string, error) {
 	fileList := []string{}