chore: fix some small issues detected by golangci-lint

But not using it as some linters are either plain incorrect (the one
suggesting to not use nil for `c.t.Context()`) or just
debatable (checking for err value is a good practice, but there are
good reasons to opt out in some cases).

cmd/components.go

@@ -36,10 +36,8 @@ func StartStopComponents(r *reporter.Reporter, daemonComponent daemon.Component,
 		Str("version", Version).Str("build-date", BuildDate).
 		Msg("akvorado has started")
 
-	select {
-	case <-daemonComponent.Terminated():
-		r.Info().Msg("stopping all components")
-	}
+	<-daemonComponent.Terminated()
+	r.Info().Msg("stopping all components")
 	return nil
 }
 

common/daemon/root.go

@@ -57,19 +57,17 @@ func (c *realComponent) Start() error {
 	// Listen for tombs
 	for _, t := range c.tombs {
 		go func(t tombWithOrigin) {
-			select {
-			case <-t.tomb.Dying():
-				if t.tomb.Err() == nil {
-					c.r.Debug().
-						Str("component", t.origin).
-						Msg("component shutting down, quitting")
-				} else {
-					c.r.Err(t.tomb.Err()).
-						Str("component", t.origin).
-						Msg("component error, quitting")
-				}
-				c.Terminate()
+			<-t.tomb.Dying()
+			if t.tomb.Err() == nil {
+				c.r.Debug().
+					Str("component", t.origin).
+					Msg("component shutting down, quitting")
+			} else {
+				c.r.Err(t.tomb.Err()).
+					Str("component", t.origin).
+					Msg("component error, quitting")
 			}
+			c.Terminate()
 		}(t)
 	}
 	// On signal, terminate

common/daemon/tests.go

@@ -40,5 +40,4 @@ func (c *MockComponent) Stop() error {
 
 // Track does nothing
 func (c *MockComponent) Track(t *tomb.Tomb, who string) {
-	return
 }

common/http/root.go

@@ -100,26 +100,6 @@ func New(r *reporter.Reporter, configuration Configuration, dependencies Depende
 	return &c, nil
 }
 
-type responseWriter struct {
-	http.ResponseWriter
-	status      int
-	wroteHeader bool
-}
-
-func (rw *responseWriter) Status() int {
-	return rw.status
-}
-
-func (rw *responseWriter) WriteHeader(code int) {
-	if rw.wroteHeader {
-		return
-	}
-	rw.status = code
-	rw.ResponseWriter.WriteHeader(code)
-	rw.wroteHeader = true
-	return
-}
-
 // AddHandler registers a new handler for the web server
 func (c *Component) AddHandler(location string, handler http.Handler) {
 	l := c.r.With().Str("handler", location).Logger()
@@ -175,16 +155,14 @@ func (c *Component) Start() error {
 
 	// Gracefully stop when asked to
 	c.t.Go(func() error {
-		select {
-		case <-c.t.Dying():
-			ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
-			defer cancel()
-			if err := server.Shutdown(ctx); err != nil {
-				c.r.Err(err).Msg("unable to shutdown HTTP server")
-				return fmt.Errorf("unable to shutdown HTTP server: %w", err)
-			}
-			return nil
+		<-c.t.Dying()
+		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer cancel()
+		if err := server.Shutdown(ctx); err != nil {
+			c.r.Err(err).Msg("unable to shutdown HTTP server")
+			return fmt.Errorf("unable to shutdown HTTP server: %w", err)
 		}
+		return nil
 	})
 	return nil
 }

common/reporter/healthcheck_test.go

@@ -73,10 +73,8 @@ func TestHealthcheckCancelContext(t *testing.T) {
 		return reporter.HealthcheckResult{reporter.HealthcheckOK, "all well"}
 	})
 	r.RegisterHealthcheck("hc2", func(ctx context.Context) reporter.HealthcheckResult {
-		select {
-		case <-ctx.Done():
-			return reporter.HealthcheckResult{reporter.HealthcheckError, "I am late, sorry"}
-		}
+		<-ctx.Done()
+		return reporter.HealthcheckResult{reporter.HealthcheckError, "I am late, sorry"}
 	})
 	ctx, cancel := context.WithCancel(context.Background())
 	go func() {

console/authentication/handlers.go

@@ -14,16 +14,12 @@ import (
 	"io/fs"
 	"math/rand"
 	"net/http"
-	"regexp"
 
 	"github.com/gin-gonic/gin"
 )
 
-var (
-	//go:embed data/avatars
-	avatarParts  embed.FS
-	avatarRegexp = regexp.MustCompile(`^([a-z]+)_([0-9]+)\.png$`)
-)
+//go:embed data/avatars
+var avatarParts embed.FS
 
 // UserInfoHandlerFunc returns the information about the currently logged user.
 func (c *Component) UserInfoHandlerFunc(gc *gin.Context) {

console/clickhouse.go

@@ -120,11 +120,6 @@ func templateEscape(input string) string {
 	return strings.ReplaceAll(input, `{{`, `{{"{{"}}`)
 }
 
-// templateDate turns a date into an UTC string compatible with ClickHouse.
-func templateDate(input time.Time) string {
-	return input.UTC().Format("2006-01-02 15:04:05")
-}
-
 // templateWhere transforms a filter to a WHERE clause
 func templateWhere(qf queryFilter) string {
 	if qf.Filter == "" {

console/docs.go

@@ -168,7 +168,7 @@ func (r *imageEmbedder) Transform(node *ast.Document, reader text.Reader, pc par
 		switch node := n.(type) {
 		case *ast.Image:
 			path := string(node.Destination)
-			if strings.Index(path, "/") != -1 || !strings.HasSuffix(path, ".svg") {
+			if strings.Contains(path, "/") || !strings.HasSuffix(path, ".svg") {
 				break
 			}
 			f, err := r.root.Open(path)

console/filter.go

@@ -273,7 +273,6 @@ LIMIT 20`, column, column, column, column, column)
 		}
 	}
 	gc.JSON(http.StatusOK, filterCompleteHandlerOutput{filteredCompletions})
-	return
 }
 
 func (c *Component) filterSavedListHandlerFunc(gc *gin.Context) {

console/graph.go

@@ -277,11 +277,11 @@ func (c *Component) graphHandlerFunc(gc *gin.Context) {
 			lastTimeForAxis[axis] = result.Time
 		}
 		rowKey := fmt.Sprintf("%d-%s", axis, result.Dimensions)
-		row, ok := points[axis][rowKey]
+		_, ok = points[axis][rowKey]
 		if !ok {
 			// Not points for this row yet, create it
 			rows[axis][rowKey] = result.Dimensions
-			row = make([]int, len(output.Time))
+			row := make([]int, len(output.Time))
 			points[axis][rowKey] = row
 			sums[axis][rowKey] = 0
 		}

console/query.go

@@ -79,6 +79,9 @@ func (qf *queryFilter) UnmarshalText(input []byte) error {
 	}
 	meta = &filter.Meta{ReverseDirection: true}
 	reverse, err := filter.Parse("", input, filter.GlobalStore("meta", meta))
+	if err != nil {
+		return fmt.Errorf("cannot parse reverse filter: %s", filter.HumanError(err))
+	}
 	*qf = queryFilter{
 		Filter:            direct.(string),
 		ReverseFilter:     reverse.(string),

console/root.go

@@ -12,7 +12,6 @@ import (
 	"path/filepath"
 	"runtime"
 	"sync"
-	"text/template"
 	"time"
 
 	"github.com/benbjohnson/clock"
@@ -33,9 +32,6 @@ type Component struct {
 	t      tomb.Tomb
 	config Configuration
 
-	templates     map[string]*template.Template
-	templatesLock sync.RWMutex
-
 	flowsTables     []flowsTable
 	flowsTablesLock sync.RWMutex
 

demoexporter/snmp/server.go

@@ -69,10 +69,8 @@ func (c *Component) startSNMPServer() error {
 		return fmt.Errorf("unable to bind SNMP server: %w", err)
 	}
 	c.t.Go(func() error {
-		select {
-		case <-c.t.Dying():
-			server.Shutdown()
-		}
+		<-c.t.Dying()
+		server.Shutdown()
 		return nil
 	})
 

inlet/flow/decoder/netflow/root.go

@@ -218,7 +218,7 @@ func (nd *Decoder) Decode(in decoder.RawFlow) []*decoder.FlowMessage {
 		}
 	}
 
-	flowMessageSet, err := producer.ProcessMessageNetFlow(msgDec, sampling)
+	flowMessageSet, _ := producer.ProcessMessageNetFlow(msgDec, sampling)
 	for _, fmsg := range flowMessageSet {
 		fmsg.TimeReceived = ts
 		fmsg.SamplerAddress = in.Source

inlet/flow/decoder/sflow/root.go

@@ -117,7 +117,7 @@ func (nd *Decoder) Decode(in decoder.RawFlow) []*decoder.FlowMessage {
 		}
 	}
 
-	flowMessageSet, err := producer.ProcessMessageSFlow(msgDec)
+	flowMessageSet, _ := producer.ProcessMessageSFlow(msgDec)
 	for _, fmsg := range flowMessageSet {
 		fmsg.TimeReceived = ts
 		fmsg.TimeFlowStart = ts

inlet/snmp/cache.go

@@ -195,9 +195,9 @@ func (sc *snmpCache) entriesOlderThan(older time.Duration, lastAccessed bool) ma
 				what = &iface.LastUpdated
 			}
 			if atomic.LoadInt64(what) < threshold {
-				rifaces, ok := result[ip]
+				_, ok := result[ip]
 				if !ok {
-					rifaces = make(map[uint]Interface)
+					rifaces := make(map[uint]Interface)
 					result[ip] = rifaces
 				}
 				result[ip][ifindex] = iface.Interface

orchestrator/clickhouse/http.go

@@ -74,7 +74,7 @@ func (c *Component) registerHTTPHandlers() error {
 				f, err := data.Open("data/asns.csv")
 				if err != nil {
 					c.r.Err(err).Msg("unable to open data/asns.csv")
-					http.Error(w, fmt.Sprintf("Unable to open ASN file."),
+					http.Error(w, "Unable to open ASN file.",
 						http.StatusInternalServerError)
 					return
 				}