Resolved linter-identified issues for improved code quality

Signed-off-by: Vadym Fedorov <[email protected]>

.vscode/launch.json

@@ -14,7 +14,8 @@
             "args": [
                 "-f",
                 "./etc/default-counters.csv",
-                "--web-config-file=./tests/integration/testdata/web-config.yml"
+                "--web-config-file=./tests/integration/testdata/web-config.yml",
+                "--debug"
             ]
         }
     ]

pkg/cmd/app.go

@@ -15,6 +15,7 @@ import (
 
 	"github.com/NVIDIA/dcgm-exporter/pkg/dcgmexporter"
 	"github.com/NVIDIA/go-dcgm/pkg/dcgm"
+	"github.com/davecgh/go-spew/spew"
 	"github.com/sirupsen/logrus"
 	"github.com/urfave/cli/v2"
 )
@@ -61,6 +62,7 @@ var (
 	CLIConfigMapData       = "configmap-data"
 	CLIWebSystemdSocket    = "web-systemd-socket"
 	CLIWebConfigFile       = "web-config-file"
+	CLIDebugMode           = "debug"
 )
 
 func NewApp(buildVersion ...string) *cli.App {
@@ -174,6 +176,12 @@ func NewApp(buildVersion ...string) *cli.App {
 			Usage:   "TLS config file following webConfig spec.",
 			EnvVars: []string{"DCGM_EXPORTER_WEB_CONFIG_FILE"},
 		},
+		&cli.BoolFlag{
+			Name:    CLIDebugMode,
+			Value:   false,
+			Usage:   "Enable debug output",
+			EnvVars: []string{"DCGM_EXPORTER_DEBUG"},
+		},
 	}
 
 	if runtime.GOOS == "linux" {
@@ -212,6 +220,19 @@ restart:
 		return err
 	}
 
+	if config.Debug {
+		spew.Config.Indent = " "
+		spew.Config.DisablePointerAddresses = true
+		spew.Config.DisableCapacities = true
+		//enable debug logging
+		logrus.SetLevel(logrus.DebugLevel)
+		logrus.Debug("Debug output is enabled")
+	}
+
+	logrus.Debugf("Command line: %s", strings.Join(os.Args, " "))
+
+	logrus.WithField(dcgmexporter.LoggerDumpField, spew.Sdump(config)).Debug("Loaded configuration")
+
 	if config.UseRemoteHE {
 		logrus.Info("Attemping to connect to remote hostengine at ", config.RemoteHEInfo)
 		cleanup, err := dcgm.Init(dcgm.Standalone, config.RemoteHEInfo, "0")
@@ -375,5 +396,6 @@ func contextToConfig(c *cli.Context) (*dcgmexporter.Config, error) {
 		ConfigMapData:       c.String(CLIConfigMapData),
 		WebSystemdSocket:    c.Bool(CLIWebSystemdSocket),
 		WebConfigFile:       c.String(CLIWebConfigFile),
+		Debug:               c.Bool(CLIDebugMode),
 	}, nil
 }

pkg/dcgmexporter/dcgm.go

@@ -21,6 +21,13 @@ import (
 	"math/rand"
 
 	"github.com/NVIDIA/go-dcgm/pkg/dcgm"
+	"github.com/sirupsen/logrus"
+)
+
+const (
+	LoggerErrorField   = "error"
+	LoggerGroupIDField = "group_id"
+	LoggerDumpField    = "dump"
 )
 
 func NewGroup() (dcgm.GroupHandle, func(), error) {
@@ -29,7 +36,12 @@ func NewGroup() (dcgm.GroupHandle, func(), error) {
 		return dcgm.GroupHandle{}, func() {}, err
 	}
 
-	return group, func() { dcgm.DestroyGroup(group) }, nil
+	return group, func() {
+		err := dcgm.DestroyGroup(group)
+		logrus.WithFields(logrus.Fields{
+			LoggerErrorField: err,
+		}).Warn("can not destroy group")
+	}, nil
 }
 
 func NewDeviceFields(counters []Counter, entityType dcgm.Field_Entity_Group) []dcgm.Short {
@@ -56,7 +68,13 @@ func NewFieldGroup(deviceFields []dcgm.Short) (dcgm.FieldHandle, func(), error)
 		return dcgm.FieldHandle{}, func() {}, err
 	}
 
-	return fieldGroup, func() { dcgm.FieldGroupDestroy(fieldGroup) }, nil
+	return fieldGroup, func() {
+		err := dcgm.FieldGroupDestroy(fieldGroup)
+		logrus.WithFields(logrus.Fields{
+			LoggerErrorField: err,
+		}).Warn("can not destroy field group")
+
+	}, nil
 }
 
 func WatchFieldGroup(group dcgm.GroupHandle, field dcgm.FieldHandle, updateFreq int64, maxKeepAge float64, maxKeepSamples int32) error {

pkg/dcgmexporter/gpu_collector.go

@@ -33,7 +33,7 @@ func NewDCGMCollector(c []Counter, config *Config, entityType dcgm.Field_Entity_
 	}
 
 	hostname := ""
-	if config.NoHostname == false {
+	if !config.NoHostname {
 		if nodeName := os.Getenv("NODE_NAME"); nodeName != "" {
 			hostname = nodeName
 		} else {
@@ -309,8 +309,6 @@ func ToString(value dcgm.FieldValue_v1) string {
 		default:
 			return v
 		}
-	default:
-		return FailedToConvert
 	}
 
 	return FailedToConvert

pkg/dcgmexporter/kubernetes.go

@@ -28,6 +28,7 @@ import (
 	"github.com/NVIDIA/dcgm-exporter/internal/pkg/nvmlprovider"
 	"github.com/sirupsen/logrus"
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
 	podresourcesapi "k8s.io/kubelet/pkg/apis/podresources/v1alpha1"
 )
 
@@ -102,9 +103,13 @@ func connectToServer(socket string) (*grpc.ClientConn, func(), error) {
 	ctx, cancel := context.WithTimeout(context.Background(), connectionTimeout)
 	defer cancel()
 
-	conn, err := grpc.DialContext(ctx, socket, grpc.WithInsecure(), grpc.WithBlock(),
-		grpc.WithDialer(func(addr string, timeout time.Duration) (net.Conn, error) {
-			return net.DialTimeout("unix", addr, timeout)
+	conn, err := grpc.DialContext(ctx,
+		socket,
+		grpc.WithTransportCredentials(insecure.NewCredentials()),
+		grpc.WithBlock(),
+		grpc.WithContextDialer(func(ctx context.Context, addr string) (net.Conn, error) {
+			d := net.Dialer{}
+			return d.DialContext(ctx, "unix", addr)
 		}),
 	)
 

pkg/dcgmexporter/kubernetes_test.go

@@ -99,7 +99,8 @@ func StartMockServer(t *testing.T, server *grpc.Server, socket string) func() {
 	stopped := make(chan interface{})
 
 	go func() {
-		server.Serve(l)
+		err := server.Serve(l)
+		assert.NoError(t, err)
 		close(stopped)
 	}()
 

pkg/dcgmexporter/parser_test.go

@@ -1,7 +1,6 @@
 package dcgmexporter
 
 import (
-	"io/ioutil"
 	"os"
 	"testing"
 
@@ -100,7 +99,7 @@ func TestInvalidConfigMapNamespace(t *testing.T) {
 }
 
 func TestExtractCounters(t *testing.T) {
-	tmpFile, err := ioutil.TempFile(os.TempDir(), "prefix-")
+	tmpFile, err := os.CreateTemp(os.TempDir(), "prefix-")
 	if err != nil {
 		t.Fatalf("Cannot create temporary file: %v", err)
 	}

pkg/dcgmexporter/pipeline.go

@@ -24,6 +24,7 @@ import (
 	"time"
 
 	"github.com/NVIDIA/go-dcgm/pkg/dcgm"
+	"github.com/davecgh/go-spew/spew"
 	"github.com/sirupsen/logrus"
 )
 
@@ -33,6 +34,8 @@ func NewMetricsPipeline(c *Config, newDCGMCollector DCGMCollectorConstructor) (*
 		return nil, func() {}, err
 	}
 
+	logrus.WithField(LoggerDumpField, spew.Sdump(counters)).Debug("Counters are initialized")
+
 	cleanups := []func(){}
 	gpuCollector, cleanup, err := newDCGMCollector(counters, c, dcgm.FE_GPU)
 	if err != nil {

pkg/dcgmexporter/pipeline_test.go

@@ -35,6 +35,7 @@ func TestRun(t *testing.T) {
 
 	p, cleanup, err := NewMetricsPipelineWithGPUCollector(&Config{}, c)
 	defer cleanup()
+	require.NoError(t, err)
 
 	out, err := p.run()
 	require.NoError(t, err)

pkg/dcgmexporter/server.go

@@ -49,13 +49,17 @@ func NewMetricsServer(c *Config, metrics chan string) (*MetricsServer, func(), e
 	router.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("X-Content-Type-Options", "nosniff")
 		w.WriteHeader(http.StatusOK)
-		w.Write([]byte(`<html>
+		_, err := w.Write([]byte(`<html>
 			<head><title>GPU Exporter</title></head>
 			<body>
 			<h1>GPU Exporter</h1>
 			<p><a href="./metrics">Metrics</a></p>
 			</body>
 			</html>`))
+		if err != nil {
+			http.Error(w, "Failed to write response", http.StatusInternalServerError)
+			return
+		}
 	})
 
 	router.HandleFunc("/health", serverv1.Health)
@@ -105,18 +109,28 @@ func (s *MetricsServer) Run(stop chan interface{}, wg *sync.WaitGroup) {
 func (s *MetricsServer) Metrics(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("X-Content-Type-Options", "nosniff")
 	w.WriteHeader(http.StatusOK)
-	w.Write([]byte(s.getMetrics()))
+	_, err := w.Write([]byte(s.getMetrics()))
+	if err != nil {
+		http.Error(w, "Failed to write response", http.StatusInternalServerError)
+		return
+	}
 }
 
 func (s *MetricsServer) Health(w http.ResponseWriter, r *http.Request) {
 	if s.getMetrics() == "" {
 		w.Header().Set("X-Content-Type-Options", "nosniff")
 		w.WriteHeader(http.StatusServiceUnavailable)
-		w.Write([]byte("KO"))
+		_, err := w.Write([]byte("KO"))
+		if err != nil {
+			http.Error(w, "Failed to write response", http.StatusInternalServerError)
+		}
 	} else {
 		w.Header().Set("X-Content-Type-Options", "nosniff")
 		w.WriteHeader(http.StatusOK)
-		w.Write([]byte("OK"))
+		_, err := w.Write([]byte("OK"))
+		if err != nil {
+			http.Error(w, "Failed to write response", http.StatusInternalServerError)
+		}
 	}
 }