add linter and fix faults

.github/workflows/linter.yml

@@ -0,0 +1,22 @@
+name: linter
+
+on: push
+
+jobs:
+  linter:
+    runs-on: ubuntu-latest
+    steps:
+      - name: checkout
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+
+      - name: set up go
+        uses: actions/setup-go@v4
+        with:
+          go-version: ">=1.20"
+
+      - name: golangci-lint
+        uses: golangci/golangci-lint-action@v3
+        with:
+          args: --config .golangci.yml

.golangci.yml

@@ -0,0 +1,35 @@
+run:
+  timeout: 30m
+output:
+  format: line-number
+linters:
+  disable-all: false
+  enable:
+  - bodyclose
+  - depguard
+  - dogsled
+  #- dupl
+  - errcheck
+  - exportloopref
+  #- funlen
+  - gocognit
+  - goconst
+  - gocritic
+  - godox
+  - gofmt
+  - goimports
+  - gosec
+  - gosimple
+  - govet
+  - ineffassign
+  - misspell
+  - nakedret
+  - revive
+  - staticcheck
+  - stylecheck
+  - typecheck
+  - unconvert
+  - unparam
+  - unused
+  - whitespace
+  - reassign

Makefile

@@ -0,0 +1,12 @@
+all: test
+
+test:
+	@go test -v ./...
+
+check:
+	@golangci-lint run --config .golangci.yml
+
+coverage:
+	@go test -cover -coverprofile cover.out -v ./...
+	@go tool cover -func=cover.out
+	@rm -f cover.out

collectors/raw_metrics_collector.go

@@ -2,17 +2,18 @@ package collectors
 
 import (
 	"compress/gzip"
+	"io"
+	"net/http"
+	"strings"
+	"sync"
+	"time"
+
 	"github.com/bosh-prometheus/firehose_exporter/metrics"
 	"github.com/gogo/protobuf/proto"
 	"github.com/prometheus/client_golang/prometheus"
 	dto "github.com/prometheus/client_model/go"
 	"github.com/prometheus/common/expfmt"
 	log "github.com/sirupsen/logrus"
-	"io"
-	"net/http"
-	"strings"
-	"sync"
-	"time"
 )
 
 var gzipPool = sync.Pool{
@@ -32,7 +33,6 @@ func NewRawMetricsCollector(
 	pointBuffer chan []*metrics.RawMetric,
 	metricExpireIn time.Duration,
 ) *RawMetricsCollector {
-
 	return &RawMetricsCollector{
 		pointBuffer:           pointBuffer,
 		metricStore:           &sync.Map{},
@@ -46,7 +46,7 @@ func (c *RawMetricsCollector) Collect() {
 		for _, point := range points {
 			smapMetric, _ := c.metricStore.LoadOrStore(point.MetricName(), &sync.Map{})
 			point.ExpireIn(c.metricExpireIn)
-			smapMetric.(*sync.Map).Store(point.Id(), point)
+			smapMetric.(*sync.Map).Store(point.ID(), point)
 		}
 	}
 }

firehose_exporter.go

@@ -8,21 +8,19 @@ import (
 	"time"
 
 	"code.cloudfoundry.org/go-loggregator/v8"
+	"github.com/alecthomas/kingpin/v2"
 	"github.com/bosh-prometheus/firehose_exporter/collectors"
 	"github.com/bosh-prometheus/firehose_exporter/metricmaker"
 	"github.com/bosh-prometheus/firehose_exporter/metrics"
 	"github.com/bosh-prometheus/firehose_exporter/nozzle"
 	"github.com/prometheus/common/version"
 	log "github.com/sirupsen/logrus"
-	"github.com/alecthomas/kingpin/v2"
 )
 
 var (
-	retroCompatDisable = kingpin.Flag("retro_compat.disable", "Disable retro compatibility",
-	).Envar("FIREHOSE_EXPORTER_RETRO_COMPAT_DISABLE").Default("false").Bool()
+	retroCompatDisable = kingpin.Flag("retro_compat.disable", "Disable retro compatibility").Envar("FIREHOSE_EXPORTER_RETRO_COMPAT_DISABLE").Default("false").Bool()
 
-	enableRetroCompatDelta = kingpin.Flag("retro_compat.enable_delta", "Enable retro compatibility delta in counter",
-	).Envar("FIREHOSE_EXPORTER_RETRO_COMPAT_ENABLE_DELTA").Default("false").Bool()
+	enableRetroCompatDelta = kingpin.Flag("retro_compat.enable_delta", "Enable retro compatibility delta in counter").Envar("FIREHOSE_EXPORTER_RETRO_COMPAT_ENABLE_DELTA").Default("false").Bool()
 
 	loggingURL = kingpin.Flag(
 		"logging.url", "Cloud Foundry Logging endpoint ($FIREHOSE_EXPORTER_LOGGING_URL)",
@@ -48,7 +46,7 @@ var (
 		"metrics.batch_size", "Batch size for nozzle envelop buffer ($FIREHOSE_EXPORTER_METRICS_NAMESPACE)",
 	).Envar("FIREHOSE_EXPORTER_METRICS_BATCH_SIZE").Default("-1").Int()
 
-	metricsShardId = kingpin.Flag(
+	metricsShardID = kingpin.Flag(
 		"metrics.shard_id", "The sharding group name to use for egress from RLP ($FIREHOSE_EXPORTER_SHARD_ID)",
 	).Envar("FIREHOSE_EXPORTER_SHARD_ID").Default("firehose_exporter").String()
 
@@ -104,14 +102,11 @@ var (
 		"web.tls.key_file", "Path to a file that contains the TLS private key (PEM format) ($FIREHOSE_EXPORTER_WEB_TLS_KEYFILE)",
 	).Envar("FIREHOSE_EXPORTER_WEB_TLS_KEYFILE").ExistingFile()
 
-	enableProfiler = kingpin.Flag("profiler.enable", "Enable pprof profiling on app on /debug/pprof",
-	).Envar("FIREHOSE_EXPORTER_ENABLE_PROFILER").Default("false").Bool()
+	enableProfiler = kingpin.Flag("profiler.enable", "Enable pprof profiling on app on /debug/pprof").Envar("FIREHOSE_EXPORTER_ENABLE_PROFILER").Default("false").Bool()
 
-	logLevel = kingpin.Flag("log.level", "Only log messages with the given severity or above. Valid levels: [debug, info, warn, error, fatal]",
-	).Envar("FIREHOSE_EXPORTER_LOG_LEVEL").Default("info").String()
+	logLevel = kingpin.Flag("log.level", "Only log messages with the given severity or above. Valid levels: [debug, info, warn, error, fatal]").Envar("FIREHOSE_EXPORTER_LOG_LEVEL").Default("info").String()
 
-	logInJson = kingpin.Flag("log.in_json", "Log in json",
-	).Envar("FIREHOSE_EXPORTER_LOG_IN_JSON").Default("false").Bool()
+	logInJSON = kingpin.Flag("log.in_json", "Log in json").Envar("FIREHOSE_EXPORTER_LOG_IN_JSON").Default("false").Bool()
 )
 
 type basicAuthHandler struct {
@@ -129,7 +124,6 @@ func (h *basicAuthHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	h.handler(w, r)
-	return
 }
 
 func initLog() {
@@ -138,7 +132,7 @@ func initLog() {
 		log.Panic(err.Error())
 	}
 	log.SetLevel(logLvl)
-	if *logInJson {
+	if *logInJSON {
 		log.SetFormatter(&log.JSONFormatter{})
 	}
 }
@@ -154,7 +148,6 @@ func initMetricMaker() {
 	} else {
 		metricmaker.PrependMetricConverter(metricmaker.SuffixCounterWithTotal)
 	}
-
 }
 
 func MakeStreamer() (*loggregator.EnvelopeStreamConnector, error) {
@@ -210,7 +203,7 @@ func main() {
 	im := metrics.NewInternalMetrics(*metricsNamespace, *metricsEnvironment)
 	nozz := nozzle.NewNozzle(
 		streamer,
-		*metricsShardId,
+		*metricsShardID,
 		*metricsNodeIndex,
 		pointBuffer,
 		im,
@@ -249,7 +242,7 @@ func main() {
 		router.Handle("/debug/vars", expvar.Handler())
 	}
 	router.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
-		w.Write([]byte(`<html>
+		_, _ = w.Write([]byte(`<html>
 				             <head><title>Cloud Foundry Firehose Exporter</title></head>
 				             <body>
 				             <h1>Cloud Foundry Firehose Exporter</h1>
@@ -258,13 +251,21 @@ func main() {
 				             </html>`))
 	})
 
+	server := &http.Server{
+		Addr:              *listenAddress,
+		ReadTimeout:       time.Second * 5,
+		ReadHeaderTimeout: time.Second * 10,
+	}
+
 	if *tlsCertFile != "" && *tlsKeyFile != "" {
 		log.Infoln("Listening TLS on", *listenAddress)
-		log.Fatal(http.ListenAndServeTLS(*listenAddress, *tlsCertFile, *tlsKeyFile, router))
+		err = server.ListenAndServeTLS(*tlsCertFile, *tlsKeyFile)
 	} else {
 		log.Infoln("Listening on", *listenAddress)
-		log.Fatal(http.ListenAndServe(*listenAddress, router))
+		err = server.ListenAndServe()
 	}
+
+	log.Fatal(err)
 }
 
 func prometheusHandler(collector *collectors.RawMetricsCollector) http.Handler {

metricmaker/converters.go

@@ -33,7 +33,7 @@ func OrderAndSanitizeLabels(metric *metrics.RawMetric) {
 			continue
 		}
 		if strings.Contains(label.GetName(), "-") {
-			label.Name = proto.String(strings.Replace(label.GetName(), "-", "_", -1))
+			label.Name = proto.String(strings.ReplaceAll(label.GetName(), "-", "_"))
 		}
 		labels = append(labels, label)
 	}

metricmaker/metricmaker_suite_test.go

@@ -11,4 +11,3 @@ func TestMetricmaker(t *testing.T) {
 	RegisterFailHandler(Fail)
 	RunSpecs(t, "Metricate Suite")
 }
-

metricmaker/metricmaker_test.go

@@ -105,11 +105,11 @@ var _ = Describe("MetricMaker", func() {
 					Message: &loggregator_v2.Envelope_Gauge{
 						Gauge: &loggregator_v2.Gauge{
 							Metrics: map[string]*loggregator_v2.GaugeValue{
-								"my_metric_1": &loggregator_v2.GaugeValue{
+								"my_metric_1": {
 									Unit:  "bytes",
 									Value: 1,
 								},
-								"my_metric_2": &loggregator_v2.GaugeValue{
+								"my_metric_2": {
 									Unit:  "bytes",
 									Value: 1,
 								},

metrics/consts.go

@@ -1,8 +1,8 @@
 package metrics
 
 const (
-	GorouterHttpMetricName          = "http"
-	GorouterHttpCounterMetricName   = GorouterHttpMetricName + "_total"
-	GorouterHttpHistogramMetricName = GorouterHttpMetricName + "_duration_seconds"
-	GorouterHttpSummaryMetricName   = GorouterHttpMetricName + "_response_size_bytes"
+	GorouterHTTPMetricName          = "http"
+	GorouterHTTPCounterMetricName   = GorouterHTTPMetricName + "_total"
+	GorouterHTTPHistogramMetricName = GorouterHTTPMetricName + "_duration_seconds"
+	GorouterHTTPSummaryMetricName   = GorouterHTTPMetricName + "_response_size_bytes"
 )

metrics/internal_metrics.go

@@ -20,8 +20,8 @@ type InternalMetrics struct {
 	LastCounterEventReceivedTimestamp    prometheus.Gauge
 	TotalValueMetricsReceived            prometheus.Counter
 	LastValueMetricReceivedTimestamp     prometheus.Gauge
-	TotalHttpMetricsReceived             prometheus.Counter
-	LastHttpMetricReceivedTimestamp      prometheus.Gauge
+	TotalHTTPMetricsReceived             prometheus.Counter
+	LastHTTPMetricReceivedTimestamp      prometheus.Gauge
 }
 
 func NewInternalMetrics(namespace string, environment string) *InternalMetrics {
@@ -109,7 +109,7 @@ func NewInternalMetrics(namespace string, environment string) *InternalMetrics {
 		},
 	)
 
-	im.TotalHttpMetricsReceived = promauto.NewCounter(
+	im.TotalHTTPMetricsReceived = promauto.NewCounter(
 		prometheus.CounterOpts{
 			Namespace:   namespace,
 			Subsystem:   "",
@@ -118,7 +118,7 @@ func NewInternalMetrics(namespace string, environment string) *InternalMetrics {
 			ConstLabels: prometheus.Labels{"environment": environment},
 		},
 	)
-	im.LastHttpMetricReceivedTimestamp = promauto.NewGauge(
+	im.LastHTTPMetricReceivedTimestamp = promauto.NewGauge(
 		prometheus.GaugeOpts{
 			Namespace:   namespace,
 			Subsystem:   "",

metrics/raw_metric.go

@@ -121,7 +121,7 @@ func (r *RawMetric) EstimateMetricSize() (size int) {
 	return size
 }
 
-func (r *RawMetric) Id() uint64 {
+func (r *RawMetric) ID() uint64 {
 	if r.id != 0 {
 		return r.id
 	}
@@ -131,8 +131,8 @@ func (r *RawMetric) Id() uint64 {
 		if label.GetName() == model.MetricNameLabel {
 			continue
 		}
-		xxh.WriteString("$" + label.GetName() + "$" + label.GetValue())
-		xxh.Write(separatorByteSlice)
+		_, _ = xxh.WriteString("$" + label.GetName() + "$" + label.GetValue())
+		_, _ = xxh.Write(separatorByteSlice)
 	}
 	r.id = xxh.Sum64()
 	return r.id

metrics/raw_metric_test.go

@@ -69,8 +69,8 @@ var _ = Describe("RawMetric", func() {
 				}),
 			})
 
-			Expect(m1.Id()).To(Equal(m2.Id()))
-			Expect(m1.Id()).ToNot(Equal(m3.Id()))
+			Expect(m1.ID()).To(Equal(m2.ID()))
+			Expect(m1.ID()).ToNot(Equal(m3.ID()))
 		})
 	})
 })

nozzle/filter_selector.go

@@ -9,13 +9,13 @@ import (
 type FilterSelectorType int32
 
 const (
-	FilterSelectorType_CONTAINER_METRIC FilterSelectorType = 0
-	FilterSelectorType_COUNTER_EVENT    FilterSelectorType = 1
-	FilterSelectorType_HTTP_START_STOP  FilterSelectorType = 2
-	FilterSelectorType_VALUE_METRIC     FilterSelectorType = 3
+	FilterSelectorTypeContainerMetric FilterSelectorType = 0
+	FilterSelectorTypeCounterEvent    FilterSelectorType = 1
+	FilterSelectorTypeHTTPStartStop   FilterSelectorType = 2
+	FilterSelectorTypeValueMetric     FilterSelectorType = 3
 )
 
-var FilterSelectorType_value = map[string]int32{
+var FilterSelectorTypeValue = map[string]int32{
 	"containermetric": 0,
 	"counterevent":    1,
 	"httpstartstop":   2,
@@ -60,7 +60,7 @@ func (f FilterSelector) ValueMetricDisabled() bool {
 	return f.valueMetricDisabled
 }
 
-func (f FilterSelector) HttpStartStopDisabled() bool {
+func (f FilterSelector) HTTPStartStopDisabled() bool {
 	return f.httpStartStopDisabled
 }
 
@@ -79,13 +79,13 @@ func (f FilterSelector) AllGaugeDisabled() bool {
 func (f *FilterSelector) Filters(filterSelectorTypes ...FilterSelectorType) {
 	for _, filterSelectorType := range filterSelectorTypes {
 		switch filterSelectorType {
-		case FilterSelectorType_CONTAINER_METRIC:
+		case FilterSelectorTypeContainerMetric:
 			f.containerMetricDisabled = false
-		case FilterSelectorType_COUNTER_EVENT:
+		case FilterSelectorTypeCounterEvent:
 			f.counterEventDisabled = false
-		case FilterSelectorType_HTTP_START_STOP:
+		case FilterSelectorTypeHTTPStartStop:
 			f.httpStartStopDisabled = false
-		case FilterSelectorType_VALUE_METRIC:
+		case FilterSelectorTypeValueMetric:
 			f.valueMetricDisabled = false
 		}
 	}
@@ -94,7 +94,7 @@ func (f *FilterSelector) Filters(filterSelectorTypes ...FilterSelectorType) {
 func (f *FilterSelector) FiltersByNames(filterSelectorNames ...string) {
 	filterSelectorTypes := make([]FilterSelectorType, 0)
 	for _, filterSelectorName := range filterSelectorNames {
-		if selectorType, ok := FilterSelectorType_value[strings.ToLower(filterSelectorName)]; ok {
+		if selectorType, ok := FilterSelectorTypeValue[strings.ToLower(filterSelectorName)]; ok {
 			filterSelectorTypes = append(filterSelectorTypes, FilterSelectorType(selectorType))
 		}
 	}
@@ -117,7 +117,7 @@ func (f *FilterSelector) ToSelectorTypes() []*loggregator_v2.Selector {
 			},
 		})
 	}
-	if !f.HttpStartStopDisabled() {
+	if !f.HTTPStartStopDisabled() {
 		selectors = append(selectors, &loggregator_v2.Selector{
 			Message: &loggregator_v2.Selector_Timer{
 				Timer: &loggregator_v2.TimerSelector{},