build: add more linting rules with revive

Makefile

@@ -239,8 +239,8 @@ test-coverage-js: ; $(info $(M) running JS coverage tests…) @ ## Run JS covera
 
 .PHONY: lint
 lint: .lint-go~ .lint-js~ ## Run linting
-.lint-go~: $(shell $(LSFILES) '*.go' 2> /dev/null) ; $(info $(M) running golint…)
+.lint-go~: revive.toml $(shell $(LSFILES) '*.go' 2> /dev/null) ; $(info $(M) running golint…)
-	$Q $(REVIVE) -formatter stylish -set_exit_status ./...
+	$Q $(REVIVE) -config $(PWD)/revive.toml -formatter stylish -set_exit_status ./...
 	$Q touch $@
 .lint-js~: $(shell $(LSFILES) '*.js' '*.ts' '*.vue' '*.html' 2> /dev/null)
 .lint-js~: $(GENERATED_JS) ; $(info $(M) running jslint…)

common/helpers/subnetmap.go

@@ -147,7 +147,8 @@ var subnetLookAlikeRegex = regexp.MustCompile("^([a-fA-F:.0-9]*[:.][a-fA-F:.0-9]
 
 // LooksLikeSubnetMap returns true iff the provided value could be a SubnetMap
 // (but not 100% sure).
-func LooksLikeSubnetMap(v reflect.Value) (result bool) {
+func LooksLikeSubnetMap(v reflect.Value) bool {
+	var result bool
 	if v.Kind() == reflect.Map {
 		// When we have a map, we check if all keys look like a subnet.
 		result = true
@@ -163,7 +164,7 @@ func LooksLikeSubnetMap(v reflect.Value) (result bool) {
 			}
 		}
 	}
-	return
+	return result
 }
 
 // SubnetMapUnmarshallerHook decodes SubnetMap and notably check that valid

common/reporter/metrics/root.go

@@ -55,7 +55,8 @@ func (m *Metrics) HTTPHandler() http.Handler {
 	})
 }
 
-func getPrefix(module string) (moduleName string) {
+func getPrefix(module string) string {
+	var moduleName string
 	if !strings.HasPrefix(module, stack.ModuleName) {
 		moduleName = stack.ModuleName
 	} else {
@@ -64,7 +65,7 @@ func getPrefix(module string) (moduleName string) {
 	moduleName = strings.ReplaceAll(moduleName, "/", "_")
 	moduleName = strings.ReplaceAll(moduleName, ".", "_")
 	moduleName = fmt.Sprintf("%s_", moduleName)
-	return
+	return moduleName
 }
 
 // Factory returns a factory to register new metrics with promauto. It

outlet/clickhouse/functional_test.go

@@ -188,6 +188,7 @@ func TestMultipleServers(t *testing.T) {
 	for range 10 {
 		r := reporter.NewMock(t)
 		sch := schema.NewMock(t)
+		func() {
 			ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
 			defer cancel()
 			ctx = clickhousego.Context(ctx, clickhousego.WithSettings(clickhousego.Settings{
@@ -223,6 +224,7 @@ func TestMultipleServers(t *testing.T) {
 			bf.Finalize()
 			w := ch.NewWorker(1, bf)
 			w.Flush(ctx)
+		}()
 
 		// Check metrics
 		gotMetrics := r.GetMetrics("akvorado_outlet_clickhouse_", "errors_total")

outlet/core/enricher.go

@@ -19,11 +19,14 @@ type exporterAndInterfaceInfo struct {
 }
 
 // enrichFlow adds more data to a flow.
-func (w *worker) enrichFlow(exporterIP netip.Addr, exporterStr string) (skip bool) {
+func (w *worker) enrichFlow(exporterIP netip.Addr, exporterStr string) bool {
-	var flowExporterName string
+	var (
-	var flowInIfName, flowInIfDescription, flowOutIfName, flowOutIfDescription string
+		flowExporterName                                                       string
-	var flowInIfSpeed, flowOutIfSpeed, flowInIfIndex, flowOutIfIndex uint32
+		flowInIfName, flowInIfDescription, flowOutIfName, flowOutIfDescription string
-	var flowInIfVlan, flowOutIfVlan uint16
+		flowInIfSpeed, flowOutIfSpeed, flowInIfIndex, flowOutIfIndex           uint32
+		flowInIfVlan, flowOutIfVlan                                            uint16
+	)
+	var skip bool
 
 	t := time.Now() // only call it once
 	expClassification := exporterClassification{}
@@ -102,7 +105,7 @@ func (w *worker) enrichFlow(exporterIP netip.Addr, exporterStr string) (skip boo
 	}
 
 	if skip {
-		return
+		return true
 	}
 
 	// Classification
@@ -148,7 +151,7 @@ func (w *worker) enrichFlow(exporterIP netip.Addr, exporterStr string) (skip boo
 	flow.AppendUint(schema.ColumnInIfSpeed, uint64(flowInIfSpeed))
 	flow.AppendUint(schema.ColumnOutIfSpeed, uint64(flowOutIfSpeed))
 
-	return
+	return skip
 }
 
 // getASNumber retrieves the AS number for a flow, depending on user preferences.

outlet/kafka/root_test.go

@@ -46,6 +46,7 @@ func TestMock(t *testing.T) {
 	}
 
 	c.Stop()
+	time.Sleep(10 * time.Millisecond)
 	if !shutdownCalled {
 		t.Error("Stop() should have triggered shutdown function")
 	}

outlet/kafka/scaler.go

@@ -72,9 +72,7 @@ func (s *scalerState) nextWorkerCount(request ScaleRequest, currentWorkers, minW
 func scaleWhileDraining(ctx context.Context, ch <-chan ScaleRequest, scaleFn func()) {
 	var wg sync.WaitGroup
 	done := make(chan struct{})
-	wg.Add(2)
+	wg.Go(func() {
-	go func() {
-		defer wg.Done()
 		for {
 			select {
 			case <-ctx.Done():
@@ -85,12 +83,11 @@ func scaleWhileDraining(ctx context.Context, ch <-chan ScaleRequest, scaleFn fun
 				// Discard signal
 			}
 		}
-	}()
+	})
-	go func() {
+	wg.Go(func() {
-		defer wg.Done()
 		scaleFn()
 		close(done)
-	}()
+	})
 	wg.Wait()
 }
 

outlet/kafka/tests.go

@@ -36,8 +36,8 @@ func (c *mockComponent) StartWorkers(workerBuilder WorkerBuilderFunc) error {
 	}()
 	for i := range c.config.MinWorkers {
 		callback, shutdown := workerBuilder(i, ch)
-		defer shutdown()
 		go func() {
+			defer shutdown()
 			for {
 				message, ok := <-c.incoming
 				if !ok {

outlet/metadata/provider/gnmi/config.go

@@ -4,7 +4,7 @@
 package gnmi
 
 import (
-	"fmt"
+	"errors"
 	"net/netip"
 	"reflect"
 	"time"
@@ -197,7 +197,7 @@ func AuthenticationParameterUnmarshallerHook() mapstructure.DecodeHookFunc {
 
 		// If we have new TLS key and any old keys, that's an error
 		if tlsKey != nil && (insecureKey != nil || skipVerifyKey != nil || tlsCAKey != nil || tlsCertKey != nil || tlsKeyKey != nil) {
-			return nil, fmt.Errorf("cannot mix old TLS configuration (Insecure, SkipVerify, TLSCA, TLSCert, TLSKey) with new TLS configuration")
+			return nil, errors.New("cannot mix old TLS configuration (Insecure, SkipVerify, TLSCA, TLSCert, TLSKey) with new TLS configuration")
 		}
 
 		// If no old keys, we need to set default TLS.Enable

revive.toml

@@ -0,0 +1,35 @@
+enableDefaultRules = true
+ignoreGeneratedHeader = false
+confidence = 0.8
+
+[rule.atomic]
+[rule.bare-return]
+[rule.blank-imports]
+[rule.bool-literal-in-expr]
+[rule.context-as-argument]
+[rule.context-keys-type]
+[rule.defer]
+[rule.dot-imports]
+[rule.empty-block]
+[rule.error-naming]
+[rule.error-return]
+[rule.error-strings]
+[rule.errorf]
+[rule.exported]
+[rule.increment-decrement]
+[rule.indent-error-flow]
+[rule.package-comments]
+[rule.range]
+[rule.receiver-naming]
+[rule.redefines-builtin-id]
+[rule.superfluous-else]
+[rule.time-equal]
+[rule.time-naming]
+[rule.unexported-return]
+[rule.unreachable-code]
+[rule.unused-parameter]
+[rule.use-any]
+[rule.use-errors-new]
+[rule.use-waitgroup-go]
+[rule.var-declaration]
+[rule.var-naming]