fix: Linter fixes for plugins/common/[a-z]* (#10189)

Co-authored-by: Pawel Zak <Pawel Zak>

plugins/common/kafka/scram_client.go

@@ -27,8 +27,7 @@ func (x *XDGSCRAMClient) Begin(userName, password, authzID string) (err error) {
 }
 
 func (x *XDGSCRAMClient) Step(challenge string) (response string, err error) {
-	response, err = x.ClientConversation.Step(challenge)
+	return x.ClientConversation.Step(challenge)
-	return
 }
 
 func (x *XDGSCRAMClient) Done() bool {

plugins/common/logrus/hook.go

@@ -14,7 +14,7 @@ var once sync.Once
 type LogHook struct {
 }
 
-// Install a logging hook into the logrus standard logger, diverting all logs
+// InstallHook installs a logging hook into the logrus standard logger, diverting all logs
 // through the Telegraf logger at debug level.  This is useful for libraries
 // that directly log to the logrus system without providing an override method.
 func InstallHook() {

plugins/common/proxy/proxy.go

@@ -14,11 +14,11 @@ type proxyFunc func(req *http.Request) (*url.URL, error)
 
 func (p *HTTPProxy) Proxy() (proxyFunc, error) {
 	if len(p.HTTPProxyURL) > 0 {
-		url, err := url.Parse(p.HTTPProxyURL)
+		address, err := url.Parse(p.HTTPProxyURL)
 		if err != nil {
 			return nil, fmt.Errorf("error parsing proxy url %q: %w", p.HTTPProxyURL, err)
 		}
-		return http.ProxyURL(url), nil
+		return http.ProxyURL(address), nil
 	}
 	return http.ProxyFromEnvironment, nil
 }

plugins/common/shim/config_test.go

@@ -5,16 +5,19 @@ import (
 	"testing"
 	"time"
 
+	"github.com/stretchr/testify/require"
+
 	"github.com/influxdata/telegraf"
 	tgConfig "github.com/influxdata/telegraf/config"
 	"github.com/influxdata/telegraf/plugins/inputs"
 	"github.com/influxdata/telegraf/plugins/processors"
-	"github.com/stretchr/testify/require"
 )
 
 func TestLoadConfig(t *testing.T) {
-	os.Setenv("SECRET_TOKEN", "xxxxxxxxxx")
+	err := os.Setenv("SECRET_TOKEN", "xxxxxxxxxx")
-	os.Setenv("SECRET_VALUE", `test"\test`)
+	require.NoError(t, err)
+	err = os.Setenv("SECRET_VALUE", `test"\test`)
+	require.NoError(t, err)
 
 	inputs.Add("test", func() telegraf.Input {
 		return &serviceInput{}

plugins/common/shim/goshim.go

@@ -84,13 +84,13 @@ func (s *Shim) Run(pollInterval time.Duration) error {
 		if err != nil {
 			return fmt.Errorf("RunProcessor error: %w", err)
 		}
-	} else if s.Output != nil {
+	} else if s.Output != nil { //nolint:revive // Not simplifying here to stay in the structure for better understanding the code
 		err := s.RunOutput()
 		if err != nil {
 			return fmt.Errorf("RunOutput error: %w", err)
 		}
 	} else {
-		return fmt.Errorf("Nothing to run")
+		return fmt.Errorf("nothing to run")
 	}
 
 	return nil
@@ -102,7 +102,7 @@ func hasQuit(ctx context.Context) bool {
 
 func (s *Shim) writeProcessedMetrics() error {
 	serializer := influx.NewSerializer()
-	for {
+	for { //nolint:gosimple // for-select used on purpose
 		select {
 		case m, open := <-s.metricCh:
 			if !open {
@@ -113,7 +113,10 @@ func (s *Shim) writeProcessedMetrics() error {
 				return fmt.Errorf("failed to serialize metric: %s", err)
 			}
 			// Write this to stdout
-			fmt.Fprint(s.stdout, string(b))
+			_, err = fmt.Fprint(s.stdout, string(b))
+			if err != nil {
+				return fmt.Errorf("failed to write metric: %s", err)
+			}
 		}
 	}
 }

plugins/common/shim/goshim_test.go

@@ -8,8 +8,9 @@ import (
 	"testing"
 	"time"
 
-	"github.com/influxdata/telegraf"
 	"github.com/stretchr/testify/require"
+
+	"github.com/influxdata/telegraf"
 )
 
 func TestShimSetsUpLogger(t *testing.T) {
@@ -18,7 +19,8 @@ func TestShimSetsUpLogger(t *testing.T) {
 
 	runErroringInputPlugin(t, 40*time.Second, stdinReader, nil, stderrWriter)
 
-	stdinWriter.Write([]byte("\n"))
+	_, err := stdinWriter.Write([]byte("\n"))
+	require.NoError(t, err)
 
 	// <-metricProcessed
 
@@ -27,7 +29,8 @@ func TestShimSetsUpLogger(t *testing.T) {
 	require.NoError(t, err)
 	require.Contains(t, out, "Error in plugin: intentional")
 
-	stdinWriter.Close()
+	err = stdinWriter.Close()
+	require.NoError(t, err)
 }
 
 func runErroringInputPlugin(t *testing.T, interval time.Duration, stdin io.Reader, stdout, stderr io.Writer) (metricProcessed chan bool, exited chan bool) {
@@ -46,7 +49,8 @@ func runErroringInputPlugin(t *testing.T, interval time.Duration, stdin io.Reade
 		shim.stderr = stderr
 		log.SetOutput(stderr)
 	}
-	shim.AddInput(inp)
+	err := shim.AddInput(inp)
+	require.NoError(t, err)
 	go func() {
 		err := shim.Run(interval)
 		require.NoError(t, err)

plugins/common/shim/input_test.go

@@ -34,7 +34,8 @@ func TestInputShimStdinSignalingWorks(t *testing.T) {
 
 	metricProcessed, exited := runInputPlugin(t, 40*time.Second, stdinReader, stdoutWriter, nil)
 
-	stdinWriter.Write([]byte("\n"))
+	_, err := stdinWriter.Write([]byte("\n"))
+	require.NoError(t, err)
 
 	<-metricProcessed
 
@@ -43,7 +44,8 @@ func TestInputShimStdinSignalingWorks(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, "measurement,tag=tag field=1i 1234000005678\n", out)
 
-	stdinWriter.Close()
+	err = stdinWriter.Close()
+	require.NoError(t, err)
 	go func() {
 		_, _ = io.ReadAll(r)
 	}()
@@ -68,7 +70,8 @@ func runInputPlugin(t *testing.T, interval time.Duration, stdin io.Reader, stdou
 	if stderr != nil {
 		shim.stderr = stderr
 	}
-	shim.AddInput(inp)
+	err := shim.AddInput(inp)
+	require.NoError(t, err)
 	go func() {
 		err := shim.Run(interval)
 		require.NoError(t, err)

plugins/common/shim/logger.go

@@ -66,7 +66,7 @@ func (l *Logger) Info(args ...interface{}) {
 // setLoggerOnPlugin injects the logger into the plugin,
 // if it defines Log telegraf.Logger. This is sort of like SetLogger but using
 // reflection instead of forcing the plugin author to define the function for it
-func setLoggerOnPlugin(i interface{}, log telegraf.Logger) {
+func setLoggerOnPlugin(i interface{}, logger telegraf.Logger) {
 	valI := reflect.ValueOf(i)
 
 	if valI.Type().Kind() != reflect.Ptr {
@@ -78,10 +78,9 @@ func setLoggerOnPlugin(i interface{}, log telegraf.Logger) {
 		return
 	}
 
-	switch field.Type().String() {
+	if field.Type().String() == "telegraf.Logger" {
-	case "telegraf.Logger":
 		if field.CanSet() {
-			field.Set(reflect.ValueOf(log))
+			field.Set(reflect.ValueOf(logger))
 		}
 	}
 }

plugins/common/shim/processor_test.go

@@ -8,11 +8,12 @@ import (
 	"testing"
 	"time"
 
+	"github.com/stretchr/testify/require"
+
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/metric"
 	"github.com/influxdata/telegraf/plugins/parsers"
 	"github.com/influxdata/telegraf/plugins/serializers"
-	"github.com/stretchr/testify/require"
 )
 
 func TestProcessorShim(t *testing.T) {
@@ -95,8 +96,8 @@ type testProcessor struct {
 }
 
 func (p *testProcessor) Apply(in ...telegraf.Metric) []telegraf.Metric {
-	for _, metric := range in {
+	for _, m := range in {
-		metric.AddTag(p.tagName, p.tagValue)
+		m.AddTag(p.tagName, p.tagValue)
 	}
 	return in
 }

plugins/common/starlark/builtins.go

@@ -5,8 +5,9 @@ import (
 	"sort"
 	"time"
 
-	"github.com/influxdata/telegraf/metric"
 	"go.starlark.net/starlark"
+
+	"github.com/influxdata/telegraf/metric"
 )
 
 func newMetric(_ *starlark.Thread, _ *starlark.Builtin, args starlark.Tuple, kwargs []starlark.Tuple) (starlark.Value, error) {
@@ -210,11 +211,11 @@ func dictUpdate(b *starlark.Builtin, args starlark.Tuple, kwargs []starlark.Tupl
 					return nil, fmt.Errorf("dictionary update sequence element #%d is not iterable (%s)", i, pair.Type())
 				}
 				defer iter2.Done()
-				len := starlark.Len(pair)
+				length := starlark.Len(pair)
-				if len < 0 {
+				if length < 0 {
 					return nil, fmt.Errorf("dictionary update sequence element #%d has unknown length (%s)", i, pair.Type())
-				} else if len != 2 {
+				} else if length != 2 {
-					return nil, fmt.Errorf("dictionary update sequence element #%d has length %d, want 2", i, len)
+					return nil, fmt.Errorf("dictionary update sequence element #%d has length %d, want 2", i, length)
 				}
 				var k, v starlark.Value
 				iter2.Next(&k)

plugins/common/starlark/field_dict.go

@@ -6,8 +6,9 @@ import (
 	"reflect"
 	"strings"
 
-	"github.com/influxdata/telegraf"
 	"go.starlark.net/starlark"
+
+	"github.com/influxdata/telegraf"
 )
 
 // FieldDict is a starlark.Value for the metric fields.  It is heavily based on the
@@ -18,17 +19,17 @@ type FieldDict struct {
 
 func (d FieldDict) String() string {
 	buf := new(strings.Builder)
-	buf.WriteString("{")
+	buf.WriteString("{") //nolint:revive // from builder.go: "It returns the length of r and a nil error."
 	sep := ""
 	for _, item := range d.Items() {
 		k, v := item[0], item[1]
-		buf.WriteString(sep)
+		buf.WriteString(sep)        //nolint:revive // from builder.go: "It returns the length of r and a nil error."
-		buf.WriteString(k.String())
+		buf.WriteString(k.String()) //nolint:revive // from builder.go: "It returns the length of r and a nil error."
-		buf.WriteString(": ")
+		buf.WriteString(": ")       //nolint:revive // from builder.go: "It returns the length of r and a nil error."
-		buf.WriteString(v.String())
+		buf.WriteString(v.String()) //nolint:revive // from builder.go: "It returns the length of r and a nil error."
 		sep = ", "
 	}
-	buf.WriteString("}")
+	buf.WriteString("}") //nolint:revive // from builder.go: "It returns the length of r and a nil error."
 	return buf.String()
 }
 
@@ -181,7 +182,7 @@ func (d FieldDict) Delete(k starlark.Value) (v starlark.Value, found bool, err e
 	return starlark.None, false, errors.New("key must be of type 'str'")
 }
 
-// Items implements the starlark.Mapping interface.
+// Iterate implements the starlark.Iterator interface.
 func (d FieldDict) Iterate() starlark.Iterator {
 	d.fieldIterCount++
 	return &FieldIterator{Metric: d.Metric, fields: d.metric.FieldList()}

plugins/common/starlark/metric.go

@@ -6,8 +6,9 @@ import (
 	"strings"
 	"time"
 
-	"github.com/influxdata/telegraf"
 	"go.starlark.net/starlark"
+
+	"github.com/influxdata/telegraf"
 )
 
 type Metric struct {
@@ -36,15 +37,15 @@ func (m *Metric) Unwrap() telegraf.Metric {
 // it behaves more like the repr function would in Python.
 func (m *Metric) String() string {
 	buf := new(strings.Builder)
-	buf.WriteString("Metric(")
+	buf.WriteString("Metric(")           //nolint:revive // from builder.go: "It returns the length of r and a nil error."
-	buf.WriteString(m.Name().String())
+	buf.WriteString(m.Name().String())   //nolint:revive // from builder.go: "It returns the length of r and a nil error."
-	buf.WriteString(", tags=")
+	buf.WriteString(", tags=")           //nolint:revive // from builder.go: "It returns the length of r and a nil error."
-	buf.WriteString(m.Tags().String())
+	buf.WriteString(m.Tags().String())   //nolint:revive // from builder.go: "It returns the length of r and a nil error."
-	buf.WriteString(", fields=")
+	buf.WriteString(", fields=")         //nolint:revive // from builder.go: "It returns the length of r and a nil error."
-	buf.WriteString(m.Fields().String())
+	buf.WriteString(m.Fields().String()) //nolint:revive // from builder.go: "It returns the length of r and a nil error."
-	buf.WriteString(", time=")
+	buf.WriteString(", time=")           //nolint:revive // from builder.go: "It returns the length of r and a nil error."
-	buf.WriteString(m.Time().String())
+	buf.WriteString(m.Time().String())   //nolint:revive // from builder.go: "It returns the length of r and a nil error."
-	buf.WriteString(")")
+	buf.WriteString(")")                 //nolint:revive // from builder.go: "It returns the length of r and a nil error."
 	return buf.String()
 }
 

plugins/common/starlark/tag_dict.go

@@ -5,8 +5,9 @@ import (
 	"fmt"
 	"strings"
 
-	"github.com/influxdata/telegraf"
 	"go.starlark.net/starlark"
+
+	"github.com/influxdata/telegraf"
 )
 
 // TagDict is a starlark.Value for the metric tags.  It is heavily based on the
@@ -17,17 +18,17 @@ type TagDict struct {
 
 func (d TagDict) String() string {
 	buf := new(strings.Builder)
-	buf.WriteString("{")
+	buf.WriteString("{") //nolint:revive // from builder.go: "It returns the length of r and a nil error."
 	sep := ""
 	for _, item := range d.Items() {
 		k, v := item[0], item[1]
-		buf.WriteString(sep)
+		buf.WriteString(sep)        //nolint:revive // from builder.go: "It returns the length of r and a nil error."
-		buf.WriteString(k.String())
+		buf.WriteString(k.String()) //nolint:revive // from builder.go: "It returns the length of r and a nil error."
-		buf.WriteString(": ")
+		buf.WriteString(": ")       //nolint:revive // from builder.go: "It returns the length of r and a nil error."
-		buf.WriteString(v.String())
+		buf.WriteString(v.String()) //nolint:revive // from builder.go: "It returns the length of r and a nil error."
 		sep = ", "
 	}
-	buf.WriteString("}")
+	buf.WriteString("}") //nolint:revive // from builder.go: "It returns the length of r and a nil error."
 	return buf.String()
 }
 
@@ -168,7 +169,7 @@ func (d TagDict) Delete(k starlark.Value) (v starlark.Value, found bool, err err
 	return starlark.None, false, errors.New("key must be of type 'str'")
 }
 
-// Items implements the starlark.Mapping interface.
+// Iterate implements the starlark.Iterator interface.
 func (d TagDict) Iterate() starlark.Iterator {
 	d.tagIterCount++
 	return &TagIterator{Metric: d.Metric, tags: d.metric.TagList()}

plugins/common/tls/config_test.go

@@ -6,9 +6,10 @@ import (
 	"testing"
 	"time"
 
+	"github.com/stretchr/testify/require"
+
 	"github.com/influxdata/telegraf/plugins/common/tls"
 	"github.com/influxdata/telegraf/testutil"
-	"github.com/stretchr/testify/require"
 )
 
 var pki = testutil.NewPKI("../../../testutil/pki")
@@ -344,6 +345,8 @@ func TestConnect(t *testing.T) {
 
 	resp, err := client.Get(ts.URL)
 	require.NoError(t, err)
+
+	defer resp.Body.Close()
 	require.Equal(t, 200, resp.StatusCode)
 }
 

plugins/common/tls/utils.go

@@ -10,11 +10,11 @@ func ParseCiphers(ciphers []string) ([]uint16, error) {
 	suites := []uint16{}
 
 	for _, cipher := range ciphers {
-		if v, ok := tlsCipherMap[cipher]; ok {
+		v, ok := tlsCipherMap[cipher]
-			suites = append(suites, v)
+		if !ok {
-		} else {
 			return nil, fmt.Errorf("unsupported cipher %q", cipher)
 		}
+		suites = append(suites, v)
 	}
 
 	return suites, nil