test(linters): Enable copyloopvar (#15532)

.golangci.yml

@@ -5,6 +5,7 @@ linters:
     - asciicheck
     - bidichk
     - bodyclose
+    - copyloopvar
     - depguard
     - dogsled
     - errcheck

plugins/common/cookie/cookie_test.go

@@ -230,7 +230,6 @@ func TestAuthConfig_Start(t *testing.T) {
 		},
 	}
 	for _, tt := range tests {
-		tt := tt
 		t.Run(tt.name, func(t *testing.T) {
 			srv := newFakeServer(t)
 			c := &CookieAuthConfig{

plugins/inputs/intel_pmu/reader.go

@@ -97,11 +97,8 @@ func (ie *iaEntitiesValuesReader) readCoreEvents(entity *CoreEventEntity) ([]cor
 	metrics := make([]coreMetric, len(entity.activeEvents))
 	errGroup := errgroup.Group{}
 
-	for i, event := range entity.activeEvents {
+	for id, actualEvent := range entity.activeEvents {
-		id := i
+		if actualEvent == nil || actualEvent.PerfEvent == nil {
-		actualEvent := event
-
-		if event == nil || event.PerfEvent == nil {
 			return nil, errors.New("active event or corresponding perf event is nil")
 		}
 
@@ -170,10 +167,7 @@ func (ie *iaEntitiesValuesReader) readMultiEventSeparately(multiEvent multiEvent
 	metrics := make([]uncoreMetric, len(activeEvents))
 	group := errgroup.Group{}
 
-	for i, event := range activeEvents {
+	for id, actualEvent := range activeEvents {
-		id := i
-		actualEvent := event
-
 		group.Go(func() error {
 			values, err := ie.eventReader.readValue(actualEvent)
 			if err != nil {
@@ -211,10 +205,7 @@ func (ie *iaEntitiesValuesReader) readMultiEventAgg(multiEvent multiEvent) (unco
 	values := make([]ia.CounterValue, len(activeEvents))
 	group := errgroup.Group{}
 
-	for i, event := range activeEvents {
+	for id, actualEvent := range activeEvents {
-		id := i
-		actualEvent := event
-
 		group.Go(func() error {
 			value, err := ie.eventReader.readValue(actualEvent)
 			if err != nil {

plugins/inputs/neptune_apex/neptune_apex_test.go

@@ -44,7 +44,6 @@ func TestGather(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		test := test
 		t.Run(test.name, func(t *testing.T) {
 			var acc testutil.Accumulator
 			n.Servers = test.servers
@@ -360,7 +359,6 @@ func TestParseXML(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		test := test
 		t.Run(test.name, func(t *testing.T) {
 			var acc testutil.Accumulator
 			err := n.parseXML(&acc, test.xmlResponse)
@@ -403,7 +401,6 @@ func TestSendRequest(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		test := test
 		t.Run(test.name, func(t *testing.T) {
 			t.Parallel()
 			h := http.HandlerFunc(func(
@@ -462,7 +459,6 @@ func TestParseTime(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		test := test
 		t.Run(test.name, func(t *testing.T) {
 			t.Parallel()
 			res, err := parseTime(test.input, test.timeZone)
@@ -507,7 +503,6 @@ func TestFindProbe(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		test := test
 		t.Run(test.name, func(t *testing.T) {
 			t.Parallel()
 			index := findProbe(test.probeName, fakeProbes)

plugins/inputs/x509_cert/x509_cert_test.go

@@ -451,8 +451,7 @@ func TestServerName(t *testing.T) {
 		{name: "errors", fromCfg: "otherex.com", fromTLS: "example.com", url: "https://other.example.com", err: true},
 	}
 
-	for _, elt := range tests {
+	for _, test := range tests {
-		test := elt
 		t.Run(test.name, func(t *testing.T) {
 			sc := &X509Cert{
 				Sources:      []string{test.url},

plugins/parsers/csv/parser.go

@@ -305,8 +305,7 @@ func parseCSV(p *Parser, r io.Reader) ([]telegraf.Metric, error) {
 			continue
 		}
 		//concatenate header names
-		for i, h := range header {
+		for i, name := range header {
-			name := h
 			if p.TrimSpace {
 				name = strings.Trim(name, " ")
 			}

plugins/parsers/graphite/config.go

@@ -26,8 +26,8 @@ func (c *Config) validateTemplates() error {
 	// map to keep track of filters we see
 	filters := map[string]struct{}{}
 
-	for i, t := range c.Templates {
+	for i, template := range c.Templates {
-		parts := strings.Fields(t)
+		parts := strings.Fields(template)
 		// Ensure template string is non-empty
 		if len(parts) == 0 {
 			return fmt.Errorf("missing template at position: %d", i)
@@ -37,10 +37,9 @@ func (c *Config) validateTemplates() error {
 		}
 
 		if len(parts) > 3 {
-			return fmt.Errorf("invalid template format: %q", t)
+			return fmt.Errorf("invalid template format: %q", template)
 		}
 
-		template := t
 		filter := ""
 		tags := ""
 		if len(parts) >= 2 {

plugins/parsers/json/json_flattener.go

@@ -22,7 +22,7 @@ func (f *JSONFlattener) FlattenJSON(
 
 // FullFlattenJSON flattens nested maps/interfaces into a fields map (including bools and string)
 func (f *JSONFlattener) FullFlattenJSON(
-	fieldname string,
+	fieldName string,
 	v interface{},
 	convertString bool,
 	convertBool bool,
@@ -33,45 +33,44 @@ func (f *JSONFlattener) FullFlattenJSON(
 
 	switch t := v.(type) {
 	case map[string]interface{}:
-		for k, v := range t {
+		for fieldKey, fieldVal := range t {
-			fieldkey := k
+			if fieldName != "" {
-			if fieldname != "" {
+				fieldKey = fieldName + "_" + fieldKey
-				fieldkey = fieldname + "_" + fieldkey
 			}
 
-			err := f.FullFlattenJSON(fieldkey, v, convertString, convertBool)
+			err := f.FullFlattenJSON(fieldKey, fieldVal, convertString, convertBool)
 			if err != nil {
 				return err
 			}
 		}
 	case []interface{}:
-		for i, v := range t {
+		for i, fieldVal := range t {
-			fieldkey := strconv.Itoa(i)
+			fieldKey := strconv.Itoa(i)
-			if fieldname != "" {
+			if fieldName != "" {
-				fieldkey = fieldname + "_" + fieldkey
+				fieldKey = fieldName + "_" + fieldKey
 			}
-			err := f.FullFlattenJSON(fieldkey, v, convertString, convertBool)
+			err := f.FullFlattenJSON(fieldKey, fieldVal, convertString, convertBool)
 			if err != nil {
 				return err
 			}
 		}
 	case float64:
-		f.Fields[fieldname] = t
+		f.Fields[fieldName] = t
 	case string:
 		if !convertString {
 			return nil
 		}
-		f.Fields[fieldname] = v.(string)
+		f.Fields[fieldName] = v.(string)
 	case bool:
 		if !convertBool {
 			return nil
 		}
-		f.Fields[fieldname] = v.(bool)
+		f.Fields[fieldName] = v.(bool)
 	case nil:
 		return nil
 	default:
 		return fmt.Errorf("JSON Flattener: got unexpected type %T with value %v (%s)",
-			t, t, fieldname)
+			t, t, fieldName)
 	}
 	return nil
 }

plugins/processors/strings/strings.go

@@ -68,8 +68,7 @@ func (c *converter) convertTag(metric telegraf.Metric) {
 		tags[c.Tag] = tv
 	}
 
-	for key, value := range tags {
+	for dest, value := range tags {
-		dest := key
 		if c.Tag != "*" && c.Dest != "" {
 			dest = c.Dest
 		}
@@ -111,8 +110,7 @@ func (c *converter) convertField(metric telegraf.Metric) {
 		fields[c.Field] = fv
 	}
 
-	for key, value := range fields {
+	for dest, value := range fields {
-		dest := key
 		if c.Field != "*" && c.Dest != "" {
 			dest = c.Dest
 		}
@@ -194,7 +192,6 @@ func (s *Strings) initOnce() {
 		s.converters = append(s.converters, c)
 	}
 	for _, c := range s.Trim {
-		c := c
 		if c.Cutset != "" {
 			c.fn = func(s string) string { return strings.Trim(s, c.Cutset) }
 		} else {
@@ -203,7 +200,6 @@ func (s *Strings) initOnce() {
 		s.converters = append(s.converters, c)
 	}
 	for _, c := range s.TrimLeft {
-		c := c
 		if c.Cutset != "" {
 			c.fn = func(s string) string { return strings.TrimLeft(s, c.Cutset) }
 		} else {
@@ -212,7 +208,6 @@ func (s *Strings) initOnce() {
 		s.converters = append(s.converters, c)
 	}
 	for _, c := range s.TrimRight {
-		c := c
 		if c.Cutset != "" {
 			c.fn = func(s string) string { return strings.TrimRight(s, c.Cutset) }
 		} else {
@@ -221,17 +216,14 @@ func (s *Strings) initOnce() {
 		s.converters = append(s.converters, c)
 	}
 	for _, c := range s.TrimPrefix {
-		c := c
 		c.fn = func(s string) string { return strings.TrimPrefix(s, c.Prefix) }
 		s.converters = append(s.converters, c)
 	}
 	for _, c := range s.TrimSuffix {
-		c := c
 		c.fn = func(s string) string { return strings.TrimSuffix(s, c.Suffix) }
 		s.converters = append(s.converters, c)
 	}
 	for _, c := range s.Replace {
-		c := c
 		c.fn = func(s string) string {
 			newString := strings.ReplaceAll(s, c.Old, c.New)
 			if newString == "" {
@@ -243,7 +235,6 @@ func (s *Strings) initOnce() {
 		s.converters = append(s.converters, c)
 	}
 	for _, c := range s.Left {
-		c := c
 		c.fn = func(s string) string {
 			if len(s) < c.Width {
 				return s
@@ -254,7 +245,6 @@ func (s *Strings) initOnce() {
 		s.converters = append(s.converters, c)
 	}
 	for _, c := range s.Base64Decode {
-		c := c
 		c.fn = func(s string) string {
 			data, err := base64.StdEncoding.DecodeString(s)
 			if err != nil {
@@ -268,7 +258,6 @@ func (s *Strings) initOnce() {
 		s.converters = append(s.converters, c)
 	}
 	for _, c := range s.ValidUTF8 {
-		c := c
 		c.fn = func(s string) string { return strings.ToValidUTF8(s, c.Replacement) }
 		s.converters = append(s.converters, c)
 	}

tools/config_includer/generator.go

@@ -120,11 +120,11 @@ func main() {
 			}
 			pwd = string(filepath.Separator) + pwd
 			for _, iname := range extractIncludes(tmpl) {
-				ifn := iname
+				if !strings.HasPrefix(iname, "/") {
-				if !strings.HasPrefix(ifn, "/") {
+					newUnresolved[iname] = filepath.Join(pwd, iname)
-					ifn = filepath.Join(pwd, ifn)
+				} else {
+					newUnresolved[iname] = iname
 				}
-				newUnresolved[iname] = ifn
 			}
 		}
 		unresolved = newUnresolved