chore: Fix linter findings for errorlint (part3) (#12704)

Co-authored-by: Pawel Zak <Pawel Zak>
(cherry picked from commit 39d6b1d)

plugins/outputs/amon/amon.go

@@ -83,17 +83,17 @@ func (a *Amon) Write(metrics []telegraf.Metric) error {
 	copy(ts.Series, tempSeries[0:])
 	tsBytes, err := json.Marshal(ts)
 	if err != nil {
-		return fmt.Errorf("unable to marshal TimeSeries, %s", err.Error())
+		return fmt.Errorf("unable to marshal TimeSeries: %w", err)
 	}
 	req, err := http.NewRequest("POST", a.authenticatedURL(), bytes.NewBuffer(tsBytes))
 	if err != nil {
-		return fmt.Errorf("unable to create http.Request, %s", err.Error())
+		return fmt.Errorf("unable to create http.Request: %w", err)
 	}
 	req.Header.Add("Content-Type", "application/json")
 
 	resp, err := a.client.Do(req)
 	if err != nil {
-		return fmt.Errorf("error POSTing metrics, %s", err.Error())
+		return fmt.Errorf("error POSTing metrics: %w", err)
 	}
 	defer resp.Body.Close()
 
@@ -113,7 +113,7 @@ func buildMetrics(m telegraf.Metric) (map[string]Point, error) {
 	for k, v := range m.Fields() {
 		var p Point
 		if err := p.setValue(v); err != nil {
-			return ms, fmt.Errorf("unable to extract value from Fields, %s", err.Error())
+			return ms, fmt.Errorf("unable to extract value from Fields: %w", err)
 		}
 		p[0] = float64(m.Time().Unix())
 		ms[k] = p

plugins/outputs/amqp/amqp.go

@@ -4,6 +4,7 @@ package amqp
 import (
 	"bytes"
 	_ "embed"
+	"errors"
 	"strings"
 	"time"
 
@@ -160,7 +161,8 @@ func (q *AMQP) Write(metrics []telegraf.Metric) error {
 			// If this is the first attempt to publish and the connection is
 			// closed, try to reconnect and retry once.
 
-			if aerr, ok := err.(*amqp.Error); first && ok && aerr == amqp.ErrClosed {
+			var aerr *amqp.Error
+			if first && errors.As(err, &aerr) && errors.Is(aerr, amqp.ErrClosed) {
 				q.client = nil
 				err := q.publish(key, body)
 				if err != nil {

plugins/outputs/amqp/client.go

@@ -70,7 +70,7 @@ func newClient(config *ClientConfig) (*client, error) {
 
 	channel, err := client.conn.Channel()
 	if err != nil {
-		return nil, fmt.Errorf("error opening channel: %v", err)
+		return nil, fmt.Errorf("error opening channel: %w", err)
 	}
 	client.channel = channel
 
@@ -110,7 +110,7 @@ func (c *client) DeclareExchange() error {
 		)
 	}
 	if err != nil {
-		return fmt.Errorf("error declaring exchange: %v", err)
+		return fmt.Errorf("error declaring exchange: %w", err)
 	}
 	return nil
 }
@@ -139,7 +139,7 @@ func (c *client) Close() error {
 	}
 
 	err := c.conn.Close()
-	if err != nil && err != amqp.ErrClosed {
+	if err != nil && !errors.Is(err, amqp.ErrClosed) {
 		return err
 	}
 	return nil

plugins/outputs/azure_data_explorer/azure_data_explorer.go

@@ -190,12 +190,12 @@ func (adx *AzureDataExplorer) getMetricIngestor(ctx context.Context, tableName s
 
 	if ingestor == nil {
 		if err := adx.createAzureDataExplorerTable(ctx, tableName); err != nil {
-			return nil, fmt.Errorf("creating table for %q failed: %v", tableName, err)
+			return nil, fmt.Errorf("creating table for %q failed: %w", tableName, err)
 		}
 		//create a new ingestor client for the table
 		tempIngestor, err := createIngestorByTable(adx.kustoClient, adx.Database, tableName, adx.IngestionType)
 		if err != nil {
-			return nil, fmt.Errorf("creating ingestor for %q failed: %v", tableName, err)
+			return nil, fmt.Errorf("creating ingestor for %q failed: %w", tableName, err)
 		}
 		adx.metricIngestors[tableName] = tempIngestor
 		adx.Log.Debugf("Ingestor for table %s created", tableName)
@@ -225,21 +225,21 @@ func (adx *AzureDataExplorer) createAzureDataExplorerTable(ctx context.Context,
 
 func (adx *AzureDataExplorer) Init() error {
 	if adx.Endpoint == "" {
-		return errors.New("Endpoint configuration cannot be empty")
+		return errors.New("endpoint configuration cannot be empty")
 	}
 	if adx.Database == "" {
-		return errors.New("Database configuration cannot be empty")
+		return errors.New("database configuration cannot be empty")
 	}
 
 	adx.MetricsGrouping = strings.ToLower(adx.MetricsGrouping)
 	if adx.MetricsGrouping == singleTable && adx.TableName == "" {
-		return errors.New("Table name cannot be empty for SingleTable metrics grouping type")
+		return errors.New("table name cannot be empty for SingleTable metrics grouping type")
 	}
 	if adx.MetricsGrouping == "" {
 		adx.MetricsGrouping = tablePerMetric
 	}
 	if !(adx.MetricsGrouping == singleTable || adx.MetricsGrouping == tablePerMetric) {
-		return errors.New("Metrics grouping type is not valid")
+		return errors.New("metrics grouping type is not valid")
 	}
 
 	if adx.IngestionType == "" {

plugins/outputs/azure_data_explorer/azure_data_explorer_test.go

@@ -302,7 +302,7 @@ func TestInitBlankEndpointData(t *testing.T) {
 
 	errorInit := plugin.Init()
 	require.Error(t, errorInit)
-	require.Equal(t, "Endpoint configuration cannot be empty", errorInit.Error())
+	require.Equal(t, "endpoint configuration cannot be empty", errorInit.Error())
 }
 
 type fakeIngestor struct {

plugins/outputs/azure_monitor/azure_monitor.go

@@ -8,11 +8,11 @@ import (
 	_ "embed"
 	"encoding/binary"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"hash/fnv"
 	"io"
 	"net/http"
-	"net/url"
 	"regexp"
 	"strings"
 	"time"
@@ -187,7 +187,7 @@ func (a *AzureMonitor) initHTTPClient() {
 func vmInstanceMetadata(c *http.Client) (region string, resourceID string, err error) {
 	req, err := http.NewRequest("GET", vmInstanceMetadataURL, nil)
 	if err != nil {
-		return "", "", fmt.Errorf("error creating request: %v", err)
+		return "", "", fmt.Errorf("error creating request: %w", err)
 	}
 	req.Header.Set("Metadata", "true")
 
@@ -323,12 +323,12 @@ func (a *AzureMonitor) send(body []byte) error {
 	// refresh the token if needed.
 	req, err = autorest.CreatePreparer(a.auth.WithAuthorization()).Prepare(req)
 	if err != nil {
-		return fmt.Errorf("unable to fetch authentication credentials: %v", err)
+		return fmt.Errorf("unable to fetch authentication credentials: %w", err)
 	}
 
 	resp, err := a.client.Do(req)
 	if err != nil {
-		if err.(*url.Error).Unwrap() == context.DeadlineExceeded {
+		if errors.Is(err, context.DeadlineExceeded) {
 			a.initHTTPClient()
 		}
 

plugins/outputs/cloud_pubsub/cloud_pubsub.go

@@ -122,7 +122,7 @@ func (ps *PubSub) initPubSubClient() error {
 		option.WithUserAgent(internal.ProductToken()),
 	)
 	if err != nil {
-		return fmt.Errorf("unable to generate PubSub client: %v", err)
+		return fmt.Errorf("unable to generate PubSub client: %w", err)
 	}
 	ps.c = client
 	return nil

plugins/outputs/datadog/datadog.go

@@ -131,7 +131,7 @@ func (d *Datadog) Write(metrics []telegraf.Metric) error {
 	copy(ts.Series, tempSeries[0:])
 	tsBytes, err := json.Marshal(ts)
 	if err != nil {
-		return fmt.Errorf("unable to marshal TimeSeries, %s", err.Error())
+		return fmt.Errorf("unable to marshal TimeSeries: %w", err)
 	}
 
 	var req *http.Request
@@ -192,7 +192,7 @@ func buildMetrics(m telegraf.Metric) (map[string]Point, error) {
 		}
 		var p Point
 		if err := p.setValue(field.Value); err != nil {
-			return ms, fmt.Errorf("unable to extract value from Fields %v error %v", field.Key, err.Error())
+			return ms, fmt.Errorf("unable to extract value from Field %v: %w", field.Key, err)
 		}
 		p[0] = float64(m.Time().Unix())
 		ms[field.Key] = p

plugins/outputs/dynatrace/dynatrace.go

@@ -134,7 +134,7 @@ func (d *Dynatrace) Write(metrics []telegraf.Metric) error {
 		output := strings.Join(batch, "\n")
 		if output != "" {
 			if err := d.send(output); err != nil {
-				return fmt.Errorf("error processing data:, %s", err.Error())
+				return fmt.Errorf("error processing data: %w", err)
 			}
 		}
 	}
@@ -147,7 +147,7 @@ func (d *Dynatrace) send(msg string) error {
 	req, err := http.NewRequest("POST", d.URL, bytes.NewBufferString(msg))
 	if err != nil {
 		d.Log.Errorf("Dynatrace error: %s", err.Error())
-		return fmt.Errorf("error while creating HTTP request:, %s", err.Error())
+		return fmt.Errorf("error while creating HTTP request: %w", err)
 	}
 	req.Header.Add("Content-Type", "text/plain; charset=UTF-8")
 
@@ -160,12 +160,12 @@ func (d *Dynatrace) send(msg string) error {
 	resp, err := d.client.Do(req)
 	if err != nil {
 		d.Log.Errorf("Dynatrace error: %s", err.Error())
-		return fmt.Errorf("error while sending HTTP request:, %s", err.Error())
+		return fmt.Errorf("error while sending HTTP request: %w", err)
 	}
 	defer resp.Body.Close()
 
 	if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusAccepted && resp.StatusCode != http.StatusBadRequest {
-		return fmt.Errorf("request failed with response code:, %d", resp.StatusCode)
+		return fmt.Errorf("request failed with response code: %d", resp.StatusCode)
 	}
 
 	// print metric line results as info log

plugins/outputs/elasticsearch/elasticsearch.go

@@ -169,7 +169,7 @@ func (a *Elasticsearch) Connect() error {
 
 	elasticURL, err := url.Parse(a.URLs[0])
 	if err != nil {
-		return fmt.Errorf("parsing URL failed: %v", err)
+		return fmt.Errorf("parsing URL failed: %w", err)
 	}
 
 	clientOptions = append(clientOptions,
@@ -213,7 +213,7 @@ func (a *Elasticsearch) Connect() error {
 	esVersion, err := client.ElasticsearchVersion(a.URLs[0])
 
 	if err != nil {
-		return fmt.Errorf("elasticsearch version check failed: %s", err)
+		return fmt.Errorf("elasticsearch version check failed: %w", err)
 	}
 
 	// quit if ES version is not supported
@@ -318,7 +318,7 @@ func (a *Elasticsearch) Write(metrics []telegraf.Metric) error {
 	res, err := bulkRequest.Do(ctx)
 
 	if err != nil {
-		return fmt.Errorf("error sending bulk request to Elasticsearch: %s", err)
+		return fmt.Errorf("error sending bulk request to Elasticsearch: %w", err)
 	}
 
 	if res.Errors {
@@ -346,7 +346,7 @@ func (a *Elasticsearch) manageTemplate(ctx context.Context) error {
 	templateExists, errExists := a.Client.IndexTemplateExists(a.TemplateName).Do(ctx)
 
 	if errExists != nil {
-		return fmt.Errorf("elasticsearch template check failed, template name: %s, error: %s", a.TemplateName, errExists)
+		return fmt.Errorf("elasticsearch template check failed, template name: %s, error: %w", a.TemplateName, errExists)
 	}
 
 	templatePattern := a.IndexName
@@ -378,7 +378,7 @@ func (a *Elasticsearch) manageTemplate(ctx context.Context) error {
 		_, errCreateTemplate := a.Client.IndexPutTemplate(a.TemplateName).BodyString(tmpl.String()).Do(ctx)
 
 		if errCreateTemplate != nil {
-			return fmt.Errorf("elasticsearch failed to create index template %s : %s", a.TemplateName, errCreateTemplate)
+			return fmt.Errorf("elasticsearch failed to create index template %s: %w", a.TemplateName, errCreateTemplate)
 		}
 
 		a.Log.Debugf("Template %s created or updated\n", a.TemplateName)

plugins/outputs/exec/exec.go

@@ -4,6 +4,7 @@ package exec
 import (
 	"bytes"
 	_ "embed"
+	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -100,7 +101,7 @@ func (c *CommandRunner) Run(timeout time.Duration, command []string, environment
 	s := stderr
 
 	if err != nil {
-		if err == internal.ErrTimeout {
+		if errors.Is(err, internal.ErrTimeout) {
 			return fmt.Errorf("%q timed out and was killed", command)
 		}
 
@@ -114,10 +115,10 @@ func (c *CommandRunner) Run(timeout time.Duration, command []string, environment
 		}
 
 		if status, ok := internal.ExitStatus(err); ok {
-			return fmt.Errorf("%q exited %d with %s", command, status, err.Error())
+			return fmt.Errorf("%q exited %d with %w", command, status, err)
 		}
 
-		return fmt.Errorf("%q failed with %s", command, err.Error())
+		return fmt.Errorf("%q failed with %w", command, err)
 	}
 
 	c.cmd = cmd
@@ -164,7 +165,7 @@ func removeWindowsCarriageReturns(b bytes.Buffer) bytes.Buffer {
 			if len(byt) > 0 {
 				_, _ = buf.Write(byt)
 			}
-			if err == io.EOF {
+			if errors.Is(err, io.EOF) {
 				return buf
 			}
 		}

plugins/outputs/execd/execd.go

@@ -84,12 +84,12 @@ func (e *Execd) Write(metrics []telegraf.Metric) error {
 			if !e.IgnoreSerializationError {
 				return fmt.Errorf("error serializing metrics: %w", err)
 			}
-			e.Log.Error("Skipping metric due to a serialization error: %w", err)
+			e.Log.Errorf("Skipping metric due to a serialization error: %v", err)
 			continue
 		}
 
 		if _, err = e.process.Stdin.Write(b); err != nil {
-			return fmt.Errorf("error writing metrics %s", err)
+			return fmt.Errorf("error writing metrics: %w", err)
 		}
 	}
 	return nil

plugins/outputs/execd/execd_test.go

@@ -2,6 +2,7 @@ package execd
 
 import (
 	"bufio"
+	"errors"
 	"flag"
 	"fmt"
 	"io"
@@ -162,10 +163,11 @@ func runOutputConsumerProgram() {
 	for {
 		m, err := parser.Next()
 		if err != nil {
-			if err == influx.EOF {
+			if errors.Is(err, influx.EOF) {
 				return // stream ended
 			}
-			if parseErr, isParseError := err.(*influx.ParseError); isParseError {
+			var parseErr *influx.ParseError
+			if errors.As(err, &parseErr) {
 				fmt.Fprintf(os.Stderr, "parse ERR %v\n", parseErr)
 				//nolint:revive // error code is important for this "test"
 				os.Exit(1)

plugins/outputs/file/file.go

@@ -97,7 +97,7 @@ func (f *File) Write(metrics []telegraf.Metric) error {
 
 			_, err = f.writer.Write(b)
 			if err != nil {
-				writeErr = fmt.Errorf("failed to write message: %v", err)
+				writeErr = fmt.Errorf("failed to write message: %w", err)
 			}
 		}
 	}

plugins/outputs/graphite/graphite.go

@@ -138,7 +138,7 @@ func (g *Graphite) checkEOF(conn net.Conn) error {
 		return err
 	}
 	num, err := conn.Read(b)
-	if err == io.EOF {
+	if errors.Is(err, io.EOF) {
 		g.Log.Debugf("Conn %s is closed. closing conn explicitly", conn.RemoteAddr().String())
 		err = conn.Close()
 		g.Log.Debugf("Failed to close the connection: %v", err)
@@ -149,7 +149,8 @@ func (g *Graphite) checkEOF(conn net.Conn) error {
 		g.Log.Infof("conn %s .conn.Read data? did not expect that. data: %s", conn, b[:num])
 	}
 	// Log non-timeout errors and close.
-	if e, ok := err.(net.Error); !(ok && e.Timeout()) {
+	var netErr net.Error
+	if !(errors.As(err, &netErr) && netErr.Timeout()) {
 		g.Log.Debugf("conn %s checkEOF .conn.Read returned err != EOF, which is unexpected.  closing conn. error: %s", conn, err)
 		err = conn.Close()
 		g.Log.Debugf("Failed to close the connection: %v", err)
@@ -184,7 +185,7 @@ func (g *Graphite) Write(metrics []telegraf.Metric) error {
 		g.Log.Debugf("Reconnecting and retrying for the following servers: %s", strings.Join(g.failedServers, ","))
 		err = g.Connect()
 		if err != nil {
-			return fmt.Errorf("Failed to reconnect: %v", err)
+			return fmt.Errorf("failed to reconnect: %w", err)
 		}
 		err = g.send(batch)
 	}

plugins/outputs/graylog/graylog.go

@@ -457,9 +457,9 @@ func (g *Graylog) Write(metrics []telegraf.Metric) error {
 		}
 
 		for _, value := range values {
-			_, err := writer.Write([]byte(value))
+			_, err = writer.Write([]byte(value))
 			if err != nil {
-				return fmt.Errorf("error writing message: %q, %v", value, err)
+				return fmt.Errorf("error writing message: %q: %w", value, err)
 			}
 		}
 	}