fix: Linter fixes for plugins/outputs/[g-m]* (#10127)

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

plugins/outputs/graphite/graphite.go

@@ -113,7 +113,7 @@ func (g *Graphite) Connect() error {
 func (g *Graphite) Close() error {
 	// Closing all connections
 	for _, conn := range g.conns {
-		conn.Close()
+		_ = conn.Close()
 	}
 	return nil
 }
@@ -133,11 +133,16 @@ func (g *Graphite) Description() string {
 // props to Tv via the authors of carbon-relay-ng` for this trick.
 func (g *Graphite) checkEOF(conn net.Conn) {
 	b := make([]byte, 1024)
-	conn.SetReadDeadline(time.Now().Add(10 * time.Millisecond))
+
+	if err := conn.SetReadDeadline(time.Now().Add(10 * time.Millisecond)); err != nil {
+		g.Log.Errorf("Couldn't set read deadline for connection %s. closing conn explicitly", conn)
+		_ = conn.Close()
+		return
+	}
 	num, err := conn.Read(b)
 	if err == io.EOF {
 		g.Log.Errorf("Conn %s is closed. closing conn explicitly", conn)
-		conn.Close()
+		_ = conn.Close()
 		return
 	}
 	// just in case i misunderstand something or the remote behaves badly
@@ -147,7 +152,7 @@ func (g *Graphite) checkEOF(conn net.Conn) {
 	// Log non-timeout errors or close.
 	if e, ok := err.(net.Error); !(ok && e.Timeout()) {
 		g.Log.Errorf("conn %s checkEOF .conn.Read returned err != EOF, which is unexpected.  closing conn. error: %s", conn, err)
-		conn.Close()
+		_ = conn.Close()
 	}
 }
 
@@ -174,7 +179,7 @@ func (g *Graphite) Write(metrics []telegraf.Metric) error {
 	// try to reconnect and retry to send
 	if err != nil {
 		g.Log.Error("Graphite: Reconnecting and retrying...")
-		g.Connect()
+		_ = g.Connect()
 		err = g.send(batch)
 	}
 
@@ -189,14 +194,14 @@ func (g *Graphite) send(batch []byte) error {
 	p := rand.Perm(len(g.conns))
 	for _, n := range p {
 		if g.Timeout > 0 {
-			g.conns[n].SetWriteDeadline(time.Now().Add(time.Duration(g.Timeout) * time.Second))
+			_ = g.conns[n].SetWriteDeadline(time.Now().Add(time.Duration(g.Timeout) * time.Second))
 		}
 		g.checkEOF(g.conns[n])
 		if _, e := g.conns[n].Write(batch); e != nil {
 			// Error
 			g.Log.Errorf("Graphite Error: " + e.Error())
 			// Close explicitly and let's try the next one
-			g.conns[n].Close()
+			_ = g.conns[n].Close()
 		} else {
 			// Success
 			err = nil

plugins/outputs/graphite/graphite_test.go

@@ -8,13 +8,11 @@ import (
 	"testing"
 	"time"
 
-	"github.com/influxdata/telegraf/testutil"
+	"github.com/stretchr/testify/require"
 
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/metric"
-
+	"github.com/influxdata/telegraf/testutil"
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
 )
 
 func TestGraphiteError(t *testing.T) {
@@ -39,7 +37,7 @@ func TestGraphiteError(t *testing.T) {
 	require.NoError(t, err1)
 	err2 := g.Write(metrics)
 	require.Error(t, err2)
-	assert.Equal(t, "could not write to any Graphite server in cluster", err2.Error())
+	require.Equal(t, "could not write to any Graphite server in cluster", err2.Error())
 }
 
 func TestGraphiteOK(t *testing.T) {
@@ -490,9 +488,9 @@ func TCPServer1(t *testing.T, wg *sync.WaitGroup) {
 		reader := bufio.NewReader(conn)
 		tp := textproto.NewReader(reader)
 		data1, _ := tp.ReadLine()
-		assert.Equal(t, "my.prefix.192_168_0_1.mymeasurement.myfield 3.14 1289430000", data1)
+		require.Equal(t, "my.prefix.192_168_0_1.mymeasurement.myfield 3.14 1289430000", data1)
-		conn.Close()
+		require.NoError(t, conn.Close())
-		tcpServer.Close()
+		require.NoError(t, tcpServer.Close())
 	}()
 }
 
@@ -504,11 +502,11 @@ func TCPServer2(t *testing.T, wg *sync.WaitGroup) {
 		reader := bufio.NewReader(conn2)
 		tp := textproto.NewReader(reader)
 		data2, _ := tp.ReadLine()
-		assert.Equal(t, "my.prefix.192_168_0_1.mymeasurement 3.14 1289430000", data2)
+		require.Equal(t, "my.prefix.192_168_0_1.mymeasurement 3.14 1289430000", data2)
 		data3, _ := tp.ReadLine()
-		assert.Equal(t, "my.prefix.192_168_0_1.my_measurement 3.14 1289430000", data3)
+		require.Equal(t, "my.prefix.192_168_0_1.my_measurement 3.14 1289430000", data3)
-		conn2.Close()
+		require.NoError(t, conn2.Close())
-		tcpServer.Close()
+		require.NoError(t, tcpServer.Close())
 	}()
 }
 
@@ -520,9 +518,9 @@ func TCPServer1WithMultipleTemplates(t *testing.T, wg *sync.WaitGroup) {
 		reader := bufio.NewReader(conn)
 		tp := textproto.NewReader(reader)
 		data1, _ := tp.ReadLine()
-		assert.Equal(t, "my.prefix.mymeasurement.valuetag.192_168_0_1.myfield 3.14 1289430000", data1)
+		require.Equal(t, "my.prefix.mymeasurement.valuetag.192_168_0_1.myfield 3.14 1289430000", data1)
-		conn.Close()
+		require.NoError(t, conn.Close())
-		tcpServer.Close()
+		require.NoError(t, tcpServer.Close())
 	}()
 }
 
@@ -534,11 +532,11 @@ func TCPServer2WithMultipleTemplates(t *testing.T, wg *sync.WaitGroup) {
 		reader := bufio.NewReader(conn2)
 		tp := textproto.NewReader(reader)
 		data2, _ := tp.ReadLine()
-		assert.Equal(t, "my.prefix.mymeasurement.valuetag.192_168_0_1 3.14 1289430000", data2)
+		require.Equal(t, "my.prefix.mymeasurement.valuetag.192_168_0_1 3.14 1289430000", data2)
 		data3, _ := tp.ReadLine()
-		assert.Equal(t, "my.prefix.192_168_0_1.my_measurement.valuetag 3.14 1289430000", data3)
+		require.Equal(t, "my.prefix.192_168_0_1.my_measurement.valuetag 3.14 1289430000", data3)
-		conn2.Close()
+		require.NoError(t, conn2.Close())
-		tcpServer.Close()
+		require.NoError(t, tcpServer.Close())
 	}()
 }
 
@@ -550,9 +548,9 @@ func TCPServer1WithTags(t *testing.T, wg *sync.WaitGroup) {
 		reader := bufio.NewReader(conn)
 		tp := textproto.NewReader(reader)
 		data1, _ := tp.ReadLine()
-		assert.Equal(t, "my.prefix.mymeasurement.myfield;host=192.168.0.1 3.14 1289430000", data1)
+		require.Equal(t, "my.prefix.mymeasurement.myfield;host=192.168.0.1 3.14 1289430000", data1)
-		conn.Close()
+		require.NoError(t, conn.Close())
-		tcpServer.Close()
+		require.NoError(t, tcpServer.Close())
 	}()
 }
 
@@ -564,11 +562,11 @@ func TCPServer2WithTags(t *testing.T, wg *sync.WaitGroup) {
 		reader := bufio.NewReader(conn2)
 		tp := textproto.NewReader(reader)
 		data2, _ := tp.ReadLine()
-		assert.Equal(t, "my.prefix.mymeasurement;host=192.168.0.1 3.14 1289430000", data2)
+		require.Equal(t, "my.prefix.mymeasurement;host=192.168.0.1 3.14 1289430000", data2)
 		data3, _ := tp.ReadLine()
-		assert.Equal(t, "my.prefix.my_measurement;host=192.168.0.1 3.14 1289430000", data3)
+		require.Equal(t, "my.prefix.my_measurement;host=192.168.0.1 3.14 1289430000", data3)
-		conn2.Close()
+		require.NoError(t, conn2.Close())
-		tcpServer.Close()
+		require.NoError(t, tcpServer.Close())
 	}()
 }
 
@@ -580,9 +578,9 @@ func TCPServer1WithTagsSeparatorUnderscore(t *testing.T, wg *sync.WaitGroup) {
 		reader := bufio.NewReader(conn)
 		tp := textproto.NewReader(reader)
 		data1, _ := tp.ReadLine()
-		assert.Equal(t, "my_prefix_mymeasurement_myfield;host=192.168.0.1 3.14 1289430000", data1)
+		require.Equal(t, "my_prefix_mymeasurement_myfield;host=192.168.0.1 3.14 1289430000", data1)
-		conn.Close()
+		require.NoError(t, conn.Close())
-		tcpServer.Close()
+		require.NoError(t, tcpServer.Close())
 	}()
 }
 
@@ -594,10 +592,10 @@ func TCPServer2WithTagsSeparatorUnderscore(t *testing.T, wg *sync.WaitGroup) {
 		reader := bufio.NewReader(conn2)
 		tp := textproto.NewReader(reader)
 		data2, _ := tp.ReadLine()
-		assert.Equal(t, "my_prefix_mymeasurement;host=192.168.0.1 3.14 1289430000", data2)
+		require.Equal(t, "my_prefix_mymeasurement;host=192.168.0.1 3.14 1289430000", data2)
 		data3, _ := tp.ReadLine()
-		assert.Equal(t, "my_prefix_my_measurement;host=192.168.0.1 3.14 1289430000", data3)
+		require.Equal(t, "my_prefix_my_measurement;host=192.168.0.1 3.14 1289430000", data3)
-		conn2.Close()
+		require.NoError(t, conn2.Close())
-		tcpServer.Close()
+		require.NoError(t, tcpServer.Close())
 	}()
 }

plugins/outputs/graylog/graylog.go

@@ -97,7 +97,10 @@ func newGelfWriter(cfg gelfConfig, dialer *net.Dialer, tlsConfig *tls.Config) ge
 }
 
 func (g *gelfUDP) Write(message []byte) (n int, err error) {
-	compressed := g.compress(message)
+	compressed, err := g.compress(message)
+	if err != nil {
+		return 0, err
+	}
 
 	chunksize := g.gelfConfig.MaxChunkSizeWan
 	length := compressed.Len()
@@ -106,10 +109,17 @@ func (g *gelfUDP) Write(message []byte) (n int, err error) {
 		chunkCountInt := int(math.Ceil(float64(length) / float64(chunksize)))
 
 		id := make([]byte, 8)
-		rand.Read(id)
+		_, err = rand.Read(id)
+		if err != nil {
+			return 0, err
+		}
 
 		for i, index := 0, 0; i < length; i, index = i+chunksize, index+1 {
-			packet := g.createChunkedMessage(index, chunkCountInt, id, &compressed)
+			packet, err := g.createChunkedMessage(index, chunkCountInt, id, &compressed)
+			if err != nil {
+				return 0, err
+			}
+
 			err = g.send(packet.Bytes())
 			if err != nil {
 				return 0, err
@@ -136,21 +146,40 @@ func (g *gelfUDP) Close() (err error) {
 	return err
 }
 
-func (g *gelfUDP) createChunkedMessage(index int, chunkCountInt int, id []byte, compressed *bytes.Buffer) bytes.Buffer {
+func (g *gelfUDP) createChunkedMessage(index int, chunkCountInt int, id []byte, compressed *bytes.Buffer) (bytes.Buffer, error) {
 	var packet bytes.Buffer
 
 	chunksize := g.getChunksize()
 
-	packet.Write(g.intToBytes(30))
+	b, err := g.intToBytes(30)
-	packet.Write(g.intToBytes(15))
+	if err != nil {
-	packet.Write(id)
+		return packet, err
+	}
+	packet.Write(b) //nolint:revive // from buffer.go: "err is always nil"
 
-	packet.Write(g.intToBytes(index))
+	b, err = g.intToBytes(15)
-	packet.Write(g.intToBytes(chunkCountInt))
+	if err != nil {
+		return packet, err
+	}
+	packet.Write(b) //nolint:revive // from buffer.go: "err is always nil"
 
-	packet.Write(compressed.Next(chunksize))
+	packet.Write(id) //nolint:revive // from buffer.go: "err is always nil"
 
-	return packet
+	b, err = g.intToBytes(index)
+	if err != nil {
+		return packet, err
+	}
+	packet.Write(b) //nolint:revive // from buffer.go: "err is always nil"
+
+	b, err = g.intToBytes(chunkCountInt)
+	if err != nil {
+		return packet, err
+	}
+	packet.Write(b) //nolint:revive // from buffer.go: "err is always nil"
+
+	packet.Write(compressed.Next(chunksize)) //nolint:revive // from buffer.go: "err is always nil"
+
+	return packet, nil
 }
 
 func (g *gelfUDP) getChunksize() int {
@@ -165,21 +194,30 @@ func (g *gelfUDP) getChunksize() int {
 	return g.gelfConfig.MaxChunkSizeWan
 }
 
-func (g *gelfUDP) intToBytes(i int) []byte {
+func (g *gelfUDP) intToBytes(i int) ([]byte, error) {
 	buf := new(bytes.Buffer)
 
-	binary.Write(buf, binary.LittleEndian, int8(i))
+	err := binary.Write(buf, binary.LittleEndian, int8(i))
-	return buf.Bytes()
+	if err != nil {
+		return nil, err
 	}
 
-func (g *gelfUDP) compress(b []byte) bytes.Buffer {
+	return buf.Bytes(), err
+}
+
+func (g *gelfUDP) compress(b []byte) (bytes.Buffer, error) {
 	var buf bytes.Buffer
 	comp := zlib.NewWriter(&buf)
 
-	comp.Write(b)
+	if _, err := comp.Write(b); err != nil {
-	comp.Close()
+		return bytes.Buffer{}, err
+	}
 
-	return buf
+	if err := comp.Close(); err != nil {
+		return bytes.Buffer{}, err
+	}
+
+	return buf, nil
 }
 
 func (g *gelfUDP) Connect() error {

plugins/outputs/graylog/graylog_test.go

@@ -11,11 +11,11 @@ import (
 	"testing"
 	"time"
 
+	reuse "github.com/libp2p/go-reuseport"
+	"github.com/stretchr/testify/require"
+
 	tlsint "github.com/influxdata/telegraf/plugins/common/tls"
 	"github.com/influxdata/telegraf/testutil"
-	reuse "github.com/libp2p/go-reuseport"
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
 )
 
 func TestWriteUDP(t *testing.T) {
@@ -183,14 +183,14 @@ func UDPServer(t *testing.T, wg *sync.WaitGroup, wg2 *sync.WaitGroup, config *Gr
 		var obj GelfObject
 		_ = json.Unmarshal(bufW.Bytes(), &obj)
 		require.NoError(t, err)
-		assert.Equal(t, obj["short_message"], "telegraf")
+		require.Equal(t, obj["short_message"], "telegraf")
 		if config.NameFieldNoPrefix {
-			assert.Equal(t, obj["name"], "test1")
+			require.Equal(t, obj["name"], "test1")
 		} else {
-			assert.Equal(t, obj["_name"], "test1")
+			require.Equal(t, obj["_name"], "test1")
 		}
-		assert.Equal(t, obj["_tag1"], "value1")
+		require.Equal(t, obj["_tag1"], "value1")
-		assert.Equal(t, obj["_value"], float64(1))
+		require.Equal(t, obj["_value"], float64(1))
 	}
 
 	// in UDP scenario all 4 messages are received
@@ -238,10 +238,10 @@ func TCPServer(t *testing.T, wg *sync.WaitGroup, wg2 *sync.WaitGroup, wg3 *sync.
 		var obj GelfObject
 		err = json.Unmarshal(bufW.Bytes(), &obj)
 		require.NoError(t, err)
-		assert.Equal(t, obj["short_message"], "telegraf")
+		require.Equal(t, obj["short_message"], "telegraf")
-		assert.Equal(t, obj["_name"], "test1")
+		require.Equal(t, obj["_name"], "test1")
-		assert.Equal(t, obj["_tag1"], "value1")
+		require.Equal(t, obj["_tag1"], "value1")
-		assert.Equal(t, obj["_value"], float64(1))
+		require.Equal(t, obj["_value"], float64(1))
 	}
 
 	conn := accept()

plugins/outputs/health/health.go

@@ -208,9 +208,9 @@ func (h *Health) Close() error {
 	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
 	defer cancel()
 
-	h.server.Shutdown(ctx)
+	err := h.server.Shutdown(ctx)
 	h.wg.Wait()
-	return nil
+	return err
 }
 
 // Origin returns the URL of the HTTP server.

plugins/outputs/health/health_test.go

@@ -6,10 +6,11 @@ import (
 	"testing"
 	"time"
 
+	"github.com/stretchr/testify/require"
+
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/plugins/outputs/health"
 	"github.com/influxdata/telegraf/testutil"
-	"github.com/stretchr/testify/require"
 )
 
 var pki = testutil.NewPKI("../../../testutil/pki")
@@ -119,6 +120,7 @@ func TestHealth(t *testing.T) {
 
 			resp, err := http.Get(output.Origin())
 			require.NoError(t, err)
+			defer resp.Body.Close()
 			require.Equal(t, tt.expectedCode, resp.StatusCode)
 
 			_, err = io.ReadAll(resp.Body)

plugins/outputs/http/http.go

@@ -150,7 +150,7 @@ func (h *HTTP) Write(metrics []telegraf.Metric) error {
 			return err
 		}
 
-		return h.write(reqBody)
+		return h.writeMetric(reqBody)
 	}
 
 	for _, metric := range metrics {
@@ -160,14 +160,14 @@ func (h *HTTP) Write(metrics []telegraf.Metric) error {
 			return err
 		}
 
-		if err := h.write(reqBody); err != nil {
+		if err := h.writeMetric(reqBody); err != nil {
 			return err
 		}
 	}
 	return nil
 }
 
-func (h *HTTP) write(reqBody []byte) error {
+func (h *HTTP) writeMetric(reqBody []byte) error {
 	var reqBodyBuffer io.Reader = bytes.NewBuffer(reqBody)
 
 	var err error

plugins/outputs/http/http_test.go

@@ -10,15 +10,16 @@ import (
 	"testing"
 	"time"
 
+	"github.com/stretchr/testify/require"
+
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/internal"
 	"github.com/influxdata/telegraf/metric"
 	httpconfig "github.com/influxdata/telegraf/plugins/common/http"
-	oauth "github.com/influxdata/telegraf/plugins/common/oauth"
+	"github.com/influxdata/telegraf/plugins/common/oauth"
 	"github.com/influxdata/telegraf/plugins/serializers"
 	"github.com/influxdata/telegraf/plugins/serializers/influx"
 	"github.com/influxdata/telegraf/plugins/serializers/json"
-	"github.com/stretchr/testify/require"
 )
 
 func getMetric() telegraf.Metric {
@@ -408,7 +409,8 @@ func TestOAuthClientCredentialsGrant(t *testing.T) {
 				values.Add("access_token", token)
 				values.Add("token_type", "bearer")
 				values.Add("expires_in", "3600")
-				w.Write([]byte(values.Encode()))
+				_, err = w.Write([]byte(values.Encode()))
+				require.NoError(t, err)
 			},
 			handler: func(t *testing.T, w http.ResponseWriter, r *http.Request) {
 				require.Equal(t, []string{"Bearer " + token}, r.Header["Authorization"])

plugins/outputs/influxdb/http.go

@@ -456,10 +456,10 @@ func (c *httpClient) makeQueryRequest(query string) (*http.Request, error) {
 	return req, nil
 }
 
-func (c *httpClient) makeWriteRequest(url string, body io.Reader) (*http.Request, error) {
+func (c *httpClient) makeWriteRequest(address string, body io.Reader) (*http.Request, error) {
 	var err error
 
-	req, err := http.NewRequest("POST", url, body)
+	req, err := http.NewRequest("POST", address, body)
 	if err != nil {
 		return nil, fmt.Errorf("failed creating new request: %s", err.Error())
 	}

plugins/outputs/influxdb/udp.go

@@ -106,7 +106,7 @@ func (c *udpClient) Write(ctx context.Context, metrics []telegraf.Metric) error
 			_, err = c.conn.Write(scanner.Bytes())
 		}
 		if err != nil {
-			c.conn.Close()
+			_ = c.conn.Close()
 			c.conn = nil
 			return err
 		}

plugins/outputs/influxdb/udp_test.go

@@ -11,11 +11,12 @@ import (
 	"testing"
 	"time"
 
+	"github.com/stretchr/testify/require"
+
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/metric"
 	"github.com/influxdata/telegraf/plugins/outputs/influxdb"
 	"github.com/influxdata/telegraf/testutil"
-	"github.com/stretchr/testify/require"
 )
 
 var (
@@ -91,7 +92,7 @@ func TestUDP_Simple(t *testing.T) {
 			DialContextF: func(network, address string) (influxdb.Conn, error) {
 				conn := &MockConn{
 					WriteF: func(b []byte) (n int, err error) {
-						buffer.Write(b)
+						buffer.Write(b) //nolint:revive // MockConn with always-success return
 						return 0, nil
 					},
 				}

plugins/outputs/influxdb_v2/http.go

@@ -7,7 +7,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"log"
 	"math"
 	"net"
 	"net/http"
@@ -55,6 +54,7 @@ type HTTPConfig struct {
 	TLSConfig        *tls.Config
 
 	Serializer *influx.Serializer
+	Log        telegraf.Logger
 }
 
 type httpClient struct {
@@ -71,6 +71,7 @@ type httpClient struct {
 	url        *url.URL
 	retryTime  time.Time
 	retryCount int
+	log        telegraf.Logger
 }
 
 func NewHTTPClient(config *HTTPConfig) (*httpClient, error) {
@@ -142,6 +143,7 @@ func NewHTTPClient(config *HTTPConfig) (*httpClient, error) {
 		Bucket:           config.Bucket,
 		BucketTag:        config.BucketTag,
 		ExcludeBucketTag: config.ExcludeBucketTag,
+		log:              config.Log,
 	}
 	return client, nil
 }
@@ -296,7 +298,7 @@ func (c *httpClient) writeBatch(ctx context.Context, bucket string, metrics []te
 		// Clients should *not* repeat the request and the metrics should be dropped.
 		http.StatusUnprocessableEntity,
 		http.StatusNotAcceptable:
-		log.Printf("E! [outputs.influxdb_v2] Failed to write metric (will be dropped: %s): %s\n", resp.Status, desc)
+		c.log.Errorf("Failed to write metric (will be dropped: %s): %s\n", resp.Status, desc)
 		return nil
 	case http.StatusUnauthorized, http.StatusForbidden:
 		return fmt.Errorf("failed to write metric (%s): %s", resp.Status, desc)
@@ -308,14 +310,14 @@ func (c *httpClient) writeBatch(ctx context.Context, bucket string, metrics []te
 		c.retryCount++
 		retryDuration := c.getRetryDuration(resp.Header)
 		c.retryTime = time.Now().Add(retryDuration)
-		log.Printf("W! [outputs.influxdb_v2] Failed to write; will retry in %s. (%s)\n", retryDuration, resp.Status)
+		c.log.Warnf("Failed to write; will retry in %s. (%s)\n", retryDuration, resp.Status)
 		return fmt.Errorf("waiting %s for server before sending metric again", retryDuration)
 	}
 
 	// if it's any other 4xx code, the client should not retry as it's the client's mistake.
 	// retrying will not make the request magically work.
 	if len(resp.Status) > 0 && resp.Status[0] == '4' {
-		log.Printf("E! [outputs.influxdb_v2] Failed to write metric (will be dropped: %s): %s\n", resp.Status, desc)
+		c.log.Errorf("Failed to write metric (will be dropped: %s): %s\n", resp.Status, desc)
 		return nil
 	}
 
@@ -357,10 +359,10 @@ func (c *httpClient) getRetryDuration(headers http.Header) time.Duration {
 	return time.Duration(retry*1000) * time.Millisecond
 }
 
-func (c *httpClient) makeWriteRequest(url string, body io.Reader) (*http.Request, error) {
+func (c *httpClient) makeWriteRequest(address string, body io.Reader) (*http.Request, error) {
 	var err error
 
-	req, err := http.NewRequest("POST", url, body)
+	req, err := http.NewRequest("POST", address, body)
 	if err != nil {
 		return nil, err
 	}

plugins/outputs/influxdb_v2/http_internal_test.go

@@ -11,8 +11,8 @@ import (
 )
 
 func genURL(u string) *url.URL {
-	URL, _ := url.Parse(u)
+	address, _ := url.Parse(u)
-	return URL
+	return address
 }
 
 func TestMakeWriteURL(t *testing.T) {

plugins/outputs/influxdb_v2/http_test.go

@@ -9,15 +9,16 @@ import (
 	"testing"
 	"time"
 
+	"github.com/stretchr/testify/require"
+
 	"github.com/influxdata/telegraf"
 	influxdb "github.com/influxdata/telegraf/plugins/outputs/influxdb_v2"
 	"github.com/influxdata/telegraf/testutil"
-	"github.com/stretchr/testify/require"
 )
 
 func genURL(u string) *url.URL {
-	URL, _ := url.Parse(u)
+	address, _ := url.Parse(u)
-	return URL
+	return address
 }
 func TestNewHTTPClient(t *testing.T) {
 	tests := []struct {
@@ -60,7 +61,8 @@ func TestWriteBucketTagWorksOnRetry(t *testing.T) {
 		http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 			switch r.URL.Path {
 			case "/api/v2/write":
-				r.ParseForm()
+				err := r.ParseForm()
+				require.NoError(t, err)
 				require.Equal(t, r.Form["bucket"], []string{"foo"})
 
 				body, err := io.ReadAll(r.Body)

plugins/outputs/influxdb_v2/influxdb.go

@@ -170,14 +170,14 @@ func (i *InfluxDB) Write(metrics []telegraf.Metric) error {
 	return err
 }
 
-func (i *InfluxDB) getHTTPClient(url *url.URL, proxy *url.URL) (Client, error) {
+func (i *InfluxDB) getHTTPClient(address *url.URL, proxy *url.URL) (Client, error) {
 	tlsConfig, err := i.ClientConfig.TLSConfig()
 	if err != nil {
 		return nil, err
 	}
 
-	config := &HTTPConfig{
+	httpConfig := &HTTPConfig{
-		URL:              url,
+		URL:              address,
 		Token:            i.Token,
 		Organization:     i.Organization,
 		Bucket:           i.Bucket,
@@ -190,11 +190,12 @@ func (i *InfluxDB) getHTTPClient(url *url.URL, proxy *url.URL) (Client, error) {
 		ContentEncoding:  i.ContentEncoding,
 		TLSConfig:        tlsConfig,
 		Serializer:       i.newSerializer(),
+		Log:              i.Log,
 	}
 
-	c, err := NewHTTPClient(config)
+	c, err := NewHTTPClient(httpConfig)
 	if err != nil {
-		return nil, fmt.Errorf("error creating HTTP client [%s]: %v", url, err)
+		return nil, fmt.Errorf("error creating HTTP client [%s]: %v", address, err)
 	}
 
 	return c, nil

plugins/outputs/instrumental/instrumental.go

@@ -75,9 +75,9 @@ func (i *Instrumental) Connect() error {
 }
 
 func (i *Instrumental) Close() error {
-	i.conn.Close()
+	err := i.conn.Close()
 	i.conn = nil
-	return nil
+	return err
 }
 
 func (i *Instrumental) Write(metrics []telegraf.Metric) error {
@@ -138,23 +138,23 @@ func (i *Instrumental) Write(metrics []telegraf.Metric) error {
 			splitStat := strings.SplitN(stat, " ", 3)
 			name := splitStat[0]
 			value := splitStat[1]
-			time := splitStat[2]
+			timestamp := splitStat[2]
 
 			// replace invalid components of metric name with underscore
 			cleanMetric := MetricNameReplacer.ReplaceAllString(name, "_")
 
 			if !ValueIncludesBadChar.MatchString(value) {
-				points = append(points, fmt.Sprintf("%s %s %s %s", metricType, cleanMetric, value, time))
+				points = append(points, fmt.Sprintf("%s %s %s %s", metricType, cleanMetric, value, timestamp))
 			}
 		}
 	}
 
 	allPoints := strings.Join(points, "")
-	_, err = fmt.Fprintf(i.conn, allPoints)
+	_, err = fmt.Fprint(i.conn, allPoints)
 
 	if err != nil {
 		if err == io.EOF {
-			i.Close()
+			_ = i.Close()
 		}
 
 		return err
@@ -163,7 +163,7 @@ func (i *Instrumental) Write(metrics []telegraf.Metric) error {
 	// force the connection closed after sending data
 	// to deal with various disconnection scenarios and eschew holding
 	// open idle connections en masse
-	i.Close()
+	_ = i.Close()
 
 	return nil
 }

plugins/outputs/instrumental/instrumental_test.go

@@ -8,9 +8,10 @@ import (
 	"testing"
 	"time"
 
+	"github.com/stretchr/testify/require"
+
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/metric"
-	"github.com/stretchr/testify/assert"
 )
 
 func TestWrite(t *testing.T) {
@@ -39,7 +40,8 @@ func TestWrite(t *testing.T) {
 	)
 
 	metrics := []telegraf.Metric{m1, m2}
-	i.Write(metrics)
+	err := i.Write(metrics)
+	require.NoError(t, err)
 
 	// Counter and Histogram are increments
 	m3 := metric.New(
@@ -70,7 +72,8 @@ func TestWrite(t *testing.T) {
 	)
 
 	metrics = []telegraf.Metric{m3, m4, m5, m6}
-	i.Write(metrics)
+	err = i.Write(metrics)
+	require.NoError(t, err)
 
 	wg.Wait()
 }
@@ -80,44 +83,49 @@ func TCPServer(t *testing.T, wg *sync.WaitGroup) {
 	go func() {
 		defer wg.Done()
 		conn, _ := tcpServer.Accept()
-		conn.SetDeadline(time.Now().Add(1 * time.Second))
+		err := conn.SetDeadline(time.Now().Add(1 * time.Second))
+		require.NoError(t, err)
 		reader := bufio.NewReader(conn)
 		tp := textproto.NewReader(reader)
 
 		hello, _ := tp.ReadLine()
-		assert.Equal(t, "hello version go/telegraf/1.1", hello)
+		require.Equal(t, "hello version go/telegraf/1.1", hello)
 		auth, _ := tp.ReadLine()
-		assert.Equal(t, "authenticate abc123token", auth)
+		require.Equal(t, "authenticate abc123token", auth)
-		conn.Write([]byte("ok\nok\n"))
+		_, err = conn.Write([]byte("ok\nok\n"))
+		require.NoError(t, err)
 
 		data1, _ := tp.ReadLine()
-		assert.Equal(t, "gauge my.prefix.192_168_0_1.mymeasurement.myfield 3.14 1289430000", data1)
+		require.Equal(t, "gauge my.prefix.192_168_0_1.mymeasurement.myfield 3.14 1289430000", data1)
 		data2, _ := tp.ReadLine()
-		assert.Equal(t, "gauge my.prefix.192_168_0_1.mymeasurement 3.14 1289430000", data2)
+		require.Equal(t, "gauge my.prefix.192_168_0_1.mymeasurement 3.14 1289430000", data2)
 
 		conn, _ = tcpServer.Accept()
-		conn.SetDeadline(time.Now().Add(1 * time.Second))
+		err = conn.SetDeadline(time.Now().Add(1 * time.Second))
+		require.NoError(t, err)
 		reader = bufio.NewReader(conn)
 		tp = textproto.NewReader(reader)
 
 		hello, _ = tp.ReadLine()
-		assert.Equal(t, "hello version go/telegraf/1.1", hello)
+		require.Equal(t, "hello version go/telegraf/1.1", hello)
 		auth, _ = tp.ReadLine()
-		assert.Equal(t, "authenticate abc123token", auth)
+		require.Equal(t, "authenticate abc123token", auth)
-		conn.Write([]byte("ok\nok\n"))
+		_, err = conn.Write([]byte("ok\nok\n"))
+		require.NoError(t, err)
 
 		data3, _ := tp.ReadLine()
-		assert.Equal(t, "increment my.prefix.192_168_0_1.my_histogram 3.14 1289430000", data3)
+		require.Equal(t, "increment my.prefix.192_168_0_1.my_histogram 3.14 1289430000", data3)
 
 		data4, _ := tp.ReadLine()
-		assert.Equal(t, "increment my.prefix.192_168_0_1_8888_123.bad_metric_name 1 1289430000", data4)
+		require.Equal(t, "increment my.prefix.192_168_0_1_8888_123.bad_metric_name 1 1289430000", data4)
 
 		data5, _ := tp.ReadLine()
-		assert.Equal(t, "increment my.prefix.192_168_0_1.my_counter 3.14 1289430000", data5)
+		require.Equal(t, "increment my.prefix.192_168_0_1.my_counter 3.14 1289430000", data5)
 
 		data6, _ := tp.ReadLine()
-		assert.Equal(t, "", data6)
+		require.Equal(t, "", data6)
 
-		conn.Close()
+		err = conn.Close()
+		require.NoError(t, err)
 	}()
 }

plugins/outputs/kafka/kafka.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/Shopify/sarama"
 	"github.com/gofrs/uuid"
+
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/plugins/common/kafka"
 	"github.com/influxdata/telegraf/plugins/outputs"
@@ -228,7 +229,7 @@ func ValidateTopicSuffixMethod(method string) error {
 			return nil
 		}
 	}
-	return fmt.Errorf("Unknown topic suffix method provided: %s", method)
+	return fmt.Errorf("unknown topic suffix method provided: %s", method)
 }
 
 func (k *Kafka) GetTopicName(metric telegraf.Metric) (telegraf.Metric, string) {
@@ -379,7 +380,7 @@ func (k *Kafka) Write(metrics []telegraf.Metric) error {
 					k.Log.Error("The timestamp of the message is out of acceptable range, consider increasing broker `message.timestamp.difference.max.ms`; dropping batch")
 					return nil
 				}
-				return prodErr
+				return prodErr //nolint:staticcheck // Return first error encountered
 			}
 		}
 		return err

plugins/outputs/kafka/kafka_test.go

@@ -5,11 +5,12 @@ import (
 	"time"
 
 	"github.com/Shopify/sarama"
+	"github.com/stretchr/testify/require"
+
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/metric"
 	"github.com/influxdata/telegraf/plugins/serializers"
 	"github.com/influxdata/telegraf/testutil"
-	"github.com/stretchr/testify/require"
 )
 
 type topicSuffixTestpair struct {
@@ -50,10 +51,10 @@ func TestTopicSuffixesIntegration(t *testing.T) {
 
 	topic := "Test"
 
-	metric := testutil.TestMetric(1)
+	m := testutil.TestMetric(1)
 	metricTagName := "tag1"
-	metricTagValue := metric.Tags()[metricTagName]
+	metricTagValue := m.Tags()[metricTagName]
-	metricName := metric.Name()
+	metricName := m.Name()
 
 	var testcases = []topicSuffixTestpair{
 		// This ensures empty separator is okay
@@ -85,7 +86,7 @@ func TestTopicSuffixesIntegration(t *testing.T) {
 			TopicSuffix: topicSuffix,
 		}
 
-		_, topic := k.GetTopicName(metric)
+		_, topic := k.GetTopicName(m)
 		require.Equal(t, expectedTopic, topic)
 	}
 }

plugins/outputs/kinesis/kinesis_test.go

@@ -9,12 +9,12 @@ import (
 	"github.com/aws/aws-sdk-go-v2/service/kinesis"
 	"github.com/aws/aws-sdk-go-v2/service/kinesis/types"
 	"github.com/gofrs/uuid"
+	"github.com/stretchr/testify/require"
+
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/plugins/serializers"
 	"github.com/influxdata/telegraf/plugins/serializers/influx"
 	"github.com/influxdata/telegraf/testutil"
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
 )
 
 const testPartitionKey = "partitionKey"
@@ -24,7 +24,6 @@ const testStreamName = "streamName"
 const zero int64 = 0
 
 func TestPartitionKey(t *testing.T) {
-	assert := assert.New(t)
 	testPoint := testutil.TestMetric(1)
 
 	k := KinesisOutput{
@@ -34,7 +33,7 @@ func TestPartitionKey(t *testing.T) {
 			Key:    "-",
 		},
 	}
-	assert.Equal("-", k.getPartitionKey(testPoint), "PartitionKey should be '-'")
+	require.Equal(t, "-", k.getPartitionKey(testPoint), "PartitionKey should be '-'")
 
 	k = KinesisOutput{
 		Log: testutil.Logger{},
@@ -43,7 +42,7 @@ func TestPartitionKey(t *testing.T) {
 			Key:    "tag1",
 		},
 	}
-	assert.Equal(testPoint.Tags()["tag1"], k.getPartitionKey(testPoint), "PartitionKey should be value of 'tag1'")
+	require.Equal(t, testPoint.Tags()["tag1"], k.getPartitionKey(testPoint), "PartitionKey should be value of 'tag1'")
 
 	k = KinesisOutput{
 		Log: testutil.Logger{},
@@ -53,7 +52,7 @@ func TestPartitionKey(t *testing.T) {
 			Default: "somedefault",
 		},
 	}
-	assert.Equal("somedefault", k.getPartitionKey(testPoint), "PartitionKey should use default")
+	require.Equal(t, "somedefault", k.getPartitionKey(testPoint), "PartitionKey should use default")
 
 	k = KinesisOutput{
 		Log: testutil.Logger{},
@@ -62,7 +61,7 @@ func TestPartitionKey(t *testing.T) {
 			Key:    "doesnotexist",
 		},
 	}
-	assert.Equal("telegraf", k.getPartitionKey(testPoint), "PartitionKey should be telegraf")
+	require.Equal(t, "telegraf", k.getPartitionKey(testPoint), "PartitionKey should be telegraf")
 
 	k = KinesisOutput{
 		Log: testutil.Logger{},
@@ -70,7 +69,7 @@ func TestPartitionKey(t *testing.T) {
 			Method: "not supported",
 		},
 	}
-	assert.Equal("", k.getPartitionKey(testPoint), "PartitionKey should be value of ''")
+	require.Equal(t, "", k.getPartitionKey(testPoint), "PartitionKey should be value of ''")
 
 	k = KinesisOutput{
 		Log: testutil.Logger{},
@@ -78,7 +77,7 @@ func TestPartitionKey(t *testing.T) {
 			Method: "measurement",
 		},
 	}
-	assert.Equal(testPoint.Name(), k.getPartitionKey(testPoint), "PartitionKey should be value of measurement name")
+	require.Equal(t, testPoint.Name(), k.getPartitionKey(testPoint), "PartitionKey should be value of measurement name")
 
 	k = KinesisOutput{
 		Log: testutil.Logger{},
@@ -88,14 +87,14 @@ func TestPartitionKey(t *testing.T) {
 	}
 	partitionKey := k.getPartitionKey(testPoint)
 	u, err := uuid.FromString(partitionKey)
-	assert.Nil(err, "Issue parsing UUID")
+	require.NoError(t, err, "Issue parsing UUID")
-	assert.Equal(byte(4), u.Version(), "PartitionKey should be UUIDv4")
+	require.Equal(t, byte(4), u.Version(), "PartitionKey should be UUIDv4")
 
 	k = KinesisOutput{
 		Log:          testutil.Logger{},
 		PartitionKey: "-",
 	}
-	assert.Equal("-", k.getPartitionKey(testPoint), "PartitionKey should be '-'")
+	require.Equal(t, "-", k.getPartitionKey(testPoint), "PartitionKey should be '-'")
 
 	k = KinesisOutput{
 		Log:                testutil.Logger{},
@@ -103,13 +102,11 @@ func TestPartitionKey(t *testing.T) {
 	}
 	partitionKey = k.getPartitionKey(testPoint)
 	u, err = uuid.FromString(partitionKey)
-	assert.Nil(err, "Issue parsing UUID")
+	require.NoError(t, err, "Issue parsing UUID")
-	assert.Equal(byte(4), u.Version(), "PartitionKey should be UUIDv4")
+	require.Equal(t, byte(4), u.Version(), "PartitionKey should be UUIDv4")
 }
 
 func TestWriteKinesis_WhenSuccess(t *testing.T) {
-	assert := assert.New(t)
-
 	records := []types.PutRecordsRequestEntry{
 		{
 			PartitionKey: aws.String(testPartitionKey),
@@ -135,7 +132,7 @@ func TestWriteKinesis_WhenSuccess(t *testing.T) {
 	}
 
 	elapsed := k.writeKinesis(records)
-	assert.GreaterOrEqual(elapsed.Nanoseconds(), zero)
+	require.GreaterOrEqual(t, elapsed.Nanoseconds(), zero)
 
 	svc.AssertRequests(t, []*kinesis.PutRecordsInput{
 		{
@@ -146,8 +143,6 @@ func TestWriteKinesis_WhenSuccess(t *testing.T) {
 }
 
 func TestWriteKinesis_WhenRecordErrors(t *testing.T) {
-	assert := assert.New(t)
-
 	records := []types.PutRecordsRequestEntry{
 		{
 			PartitionKey: aws.String(testPartitionKey),
@@ -173,7 +168,7 @@ func TestWriteKinesis_WhenRecordErrors(t *testing.T) {
 	}
 
 	elapsed := k.writeKinesis(records)
-	assert.GreaterOrEqual(elapsed.Nanoseconds(), zero)
+	require.GreaterOrEqual(t, elapsed.Nanoseconds(), zero)
 
 	svc.AssertRequests(t, []*kinesis.PutRecordsInput{
 		{
@@ -184,8 +179,6 @@ func TestWriteKinesis_WhenRecordErrors(t *testing.T) {
 }
 
 func TestWriteKinesis_WhenServiceError(t *testing.T) {
-	assert := assert.New(t)
-
 	records := []types.PutRecordsRequestEntry{
 		{
 			PartitionKey: aws.String(testPartitionKey),
@@ -205,7 +198,7 @@ func TestWriteKinesis_WhenServiceError(t *testing.T) {
 	}
 
 	elapsed := k.writeKinesis(records)
-	assert.GreaterOrEqual(elapsed.Nanoseconds(), zero)
+	require.GreaterOrEqual(t, elapsed.Nanoseconds(), zero)
 
 	svc.AssertRequests(t, []*kinesis.PutRecordsInput{
 		{
@@ -216,7 +209,6 @@ func TestWriteKinesis_WhenServiceError(t *testing.T) {
 }
 
 func TestWrite_NoMetrics(t *testing.T) {
-	assert := assert.New(t)
 	serializer := influx.NewSerializer()
 	svc := &mockKinesisPutRecords{}
 
@@ -232,13 +224,12 @@ func TestWrite_NoMetrics(t *testing.T) {
 	}
 
 	err := k.Write([]telegraf.Metric{})
-	assert.Nil(err, "Should not return error")
+	require.NoError(t, err, "Should not return error")
 
 	svc.AssertRequests(t, []*kinesis.PutRecordsInput{})
 }
 
 func TestWrite_SingleMetric(t *testing.T) {
-	assert := assert.New(t)
 	serializer := influx.NewSerializer()
 
 	svc := &mockKinesisPutRecords{}
@@ -257,7 +248,7 @@ func TestWrite_SingleMetric(t *testing.T) {
 
 	metric, metricData := createTestMetric(t, "metric1", serializer)
 	err := k.Write([]telegraf.Metric{metric})
-	assert.Nil(err, "Should not return error")
+	require.NoError(t, err, "Should not return error")
 
 	svc.AssertRequests(t, []*kinesis.PutRecordsInput{
 		{
@@ -273,7 +264,6 @@ func TestWrite_SingleMetric(t *testing.T) {
 }
 
 func TestWrite_MultipleMetrics_SinglePartialRequest(t *testing.T) {
-	assert := assert.New(t)
 	serializer := influx.NewSerializer()
 
 	svc := &mockKinesisPutRecords{}
@@ -292,7 +282,7 @@ func TestWrite_MultipleMetrics_SinglePartialRequest(t *testing.T) {
 
 	metrics, metricsData := createTestMetrics(t, 3, serializer)
 	err := k.Write(metrics)
-	assert.Nil(err, "Should not return error")
+	require.NoError(t, err, "Should not return error")
 
 	svc.AssertRequests(t, []*kinesis.PutRecordsInput{
 		{
@@ -305,7 +295,6 @@ func TestWrite_MultipleMetrics_SinglePartialRequest(t *testing.T) {
 }
 
 func TestWrite_MultipleMetrics_SingleFullRequest(t *testing.T) {
-	assert := assert.New(t)
 	serializer := influx.NewSerializer()
 
 	svc := &mockKinesisPutRecords{}
@@ -324,7 +313,7 @@ func TestWrite_MultipleMetrics_SingleFullRequest(t *testing.T) {
 
 	metrics, metricsData := createTestMetrics(t, maxRecordsPerRequest, serializer)
 	err := k.Write(metrics)
-	assert.Nil(err, "Should not return error")
+	require.NoError(t, err, "Should not return error")
 
 	svc.AssertRequests(t, []*kinesis.PutRecordsInput{
 		{
@@ -337,7 +326,6 @@ func TestWrite_MultipleMetrics_SingleFullRequest(t *testing.T) {
 }
 
 func TestWrite_MultipleMetrics_MultipleRequests(t *testing.T) {
-	assert := assert.New(t)
 	serializer := influx.NewSerializer()
 
 	svc := &mockKinesisPutRecords{}
@@ -357,7 +345,7 @@ func TestWrite_MultipleMetrics_MultipleRequests(t *testing.T) {
 
 	metrics, metricsData := createTestMetrics(t, maxRecordsPerRequest+1, serializer)
 	err := k.Write(metrics)
-	assert.Nil(err, "Should not return error")
+	require.NoError(t, err, "Should not return error")
 
 	svc.AssertRequests(t, []*kinesis.PutRecordsInput{
 		{
@@ -376,7 +364,6 @@ func TestWrite_MultipleMetrics_MultipleRequests(t *testing.T) {
 }
 
 func TestWrite_MultipleMetrics_MultipleFullRequests(t *testing.T) {
-	assert := assert.New(t)
 	serializer := influx.NewSerializer()
 
 	svc := &mockKinesisPutRecords{}
@@ -396,7 +383,7 @@ func TestWrite_MultipleMetrics_MultipleFullRequests(t *testing.T) {
 
 	metrics, metricsData := createTestMetrics(t, maxRecordsPerRequest*2, serializer)
 	err := k.Write(metrics)
-	assert.Nil(err, "Should not return error")
+	require.NoError(t, err, "Should not return error")
 
 	svc.AssertRequests(t, []*kinesis.PutRecordsInput{
 		{
@@ -415,7 +402,6 @@ func TestWrite_MultipleMetrics_MultipleFullRequests(t *testing.T) {
 }
 
 func TestWrite_SerializerError(t *testing.T) {
-	assert := assert.New(t)
 	serializer := influx.NewSerializer()
 
 	svc := &mockKinesisPutRecords{}
@@ -443,7 +429,7 @@ func TestWrite_SerializerError(t *testing.T) {
 		invalidMetric,
 		metric2,
 	})
-	assert.Nil(err, "Should not return error")
+	require.NoError(t, err, "Should not return error")
 
 	// remaining valid metrics should still get written
 	svc.AssertRequests(t, []*kinesis.PutRecordsInput{
@@ -519,7 +505,7 @@ func (m *mockKinesisPutRecords) SetupErrorResponse(err error) {
 func (m *mockKinesisPutRecords) PutRecords(_ context.Context, input *kinesis.PutRecordsInput, _ ...func(*kinesis.Options)) (*kinesis.PutRecordsOutput, error) {
 	reqNum := len(m.requests)
 	if reqNum > len(m.responses) {
-		return nil, fmt.Errorf("Response for request %+v not setup", reqNum)
+		return nil, fmt.Errorf("response for request %+v not setup", reqNum)
 	}
 
 	m.requests = append(m.requests, input)

plugins/outputs/librato/librato.go

@@ -118,6 +118,16 @@ func (l *Librato) Write(metrics []telegraf.Metric) error {
 	// make sur we send a batch of maximum 300
 	sizeBatch := 300
 	for start := 0; start < metricCounter; start += sizeBatch {
+		err := l.writeBatch(start, sizeBatch, metricCounter, tempGauges)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (l *Librato) writeBatch(start int, sizeBatch int, metricCounter int, tempGauges []*Gauge) error {
 	lmetrics := LMetrics{}
 	end := start + sizeBatch
 	if end > metricCounter {
@@ -163,8 +173,6 @@ func (l *Librato) Write(metrics []telegraf.Metric) error {
 		}
 		l.Log.Debugf("Librato response: %v", string(htmlData))
 	}
-	}
-
 	return nil
 }
 
@@ -219,9 +227,10 @@ func verifyValue(v interface{}) bool {
 	switch v.(type) {
 	case string:
 		return false
-	}
+	default:
 		return true
 	}
+}
 
 func (g *Gauge) setValue(v interface{}) error {
 	switch d := v.(type) {
@@ -230,7 +239,7 @@ func (g *Gauge) setValue(v interface{}) error {
 	case uint64:
 		g.Value = float64(d)
 	case float64:
-		g.Value = float64(d)
+		g.Value = d
 	case bool:
 		if d {
 			g.Value = float64(1.0)

plugins/outputs/loki/loki.go

@@ -11,13 +11,14 @@ import (
 	"strings"
 	"time"
 
+	"golang.org/x/oauth2"
+	"golang.org/x/oauth2/clientcredentials"
+
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/config"
 	"github.com/influxdata/telegraf/internal"
 	"github.com/influxdata/telegraf/plugins/common/tls"
 	"github.com/influxdata/telegraf/plugins/outputs"
-	"golang.org/x/oauth2"
-	"golang.org/x/oauth2/clientcredentials"
 )
 
 const (
@@ -126,7 +127,7 @@ func (l *Loki) Connect() (err error) {
 		return fmt.Errorf("http client fail: %w", err)
 	}
 
-	return
+	return nil
 }
 
 func (l *Loki) Close() error {
@@ -155,10 +156,10 @@ func (l *Loki) Write(metrics []telegraf.Metric) error {
 		s.insertLog(tags, Log{fmt.Sprintf("%d", m.Time().UnixNano()), line})
 	}
 
-	return l.write(s)
+	return l.writeMetrics(s)
 }
 
-func (l *Loki) write(s Streams) error {
+func (l *Loki) writeMetrics(s Streams) error {
 	bs, err := json.Marshal(s)
 	if err != nil {
 		return fmt.Errorf("json.Marshal: %w", err)

plugins/outputs/loki/loki_test.go

@@ -11,11 +11,11 @@ import (
 	"testing"
 	"time"
 
-	"github.com/influxdata/telegraf/testutil"
+	"github.com/stretchr/testify/require"
 
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/internal"
-	"github.com/stretchr/testify/require"
+	"github.com/influxdata/telegraf/testutil"
 )
 
 func getMetric() telegraf.Metric {
@@ -329,7 +329,8 @@ func TestOAuthClientCredentialsGrant(t *testing.T) {
 				values.Add("access_token", token)
 				values.Add("token_type", "bearer")
 				values.Add("expires_in", "3600")
-				w.Write([]byte(values.Encode()))
+				_, err = w.Write([]byte(values.Encode()))
+				require.NoError(t, err)
 			},
 			handler: func(t *testing.T, w http.ResponseWriter, r *http.Request) {
 				require.Equal(t, []string{"Bearer " + token}, r.Header["Authorization"])

plugins/outputs/mqtt/mqtt.go

@@ -2,12 +2,12 @@ package mqtt
 
 import (
 	"fmt"
-	"log"
 	"strings"
 	"sync"
 	"time"
 
 	paho "github.com/eclipse/paho.mqtt.golang"
+
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/config"
 	"github.com/influxdata/telegraf/internal"
@@ -85,6 +85,7 @@ type MQTT struct {
 	BatchMessage bool            `toml:"batch"`
 	Retain       bool            `toml:"retain"`
 	KeepAlive    int64           `toml:"keep_alive"`
+	Log          telegraf.Logger `toml:"-"`
 
 	client paho.Client
 	opts   *paho.ClientOptions
@@ -164,13 +165,13 @@ func (m *MQTT) Write(metrics []telegraf.Metric) error {
 		} else {
 			buf, err := m.serializer.Serialize(metric)
 			if err != nil {
-				log.Printf("D! [outputs.mqtt] Could not serialize metric: %v", err)
+				m.Log.Debugf("Could not serialize metric: %v", err)
 				continue
 			}
 
 			err = m.publish(topic, buf)
 			if err != nil {
-				return fmt.Errorf("Could not write to MQTT server, %s", err)
+				return fmt.Errorf("could not write to MQTT server, %s", err)
 			}
 		}
 	}
@@ -183,7 +184,7 @@ func (m *MQTT) Write(metrics []telegraf.Metric) error {
 		}
 		publisherr := m.publish(key, buf)
 		if publisherr != nil {
-			return fmt.Errorf("Could not write to MQTT server, %s", publisherr)
+			return fmt.Errorf("could not write to MQTT server, %s", publisherr)
 		}
 	}
 

plugins/outputs/nats/nats.go

@@ -2,14 +2,14 @@ package nats
 
 import (
 	"fmt"
-	"log"
 	"strings"
 
+	"github.com/nats-io/nats.go"
+
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/plugins/common/tls"
 	"github.com/influxdata/telegraf/plugins/outputs"
 	"github.com/influxdata/telegraf/plugins/serializers"
-	"github.com/nats-io/nats.go"
 )
 
 type NATS struct {
@@ -23,6 +23,8 @@ type NATS struct {
 
 	tls.ClientConfig
 
+	Log telegraf.Logger `toml:"-"`
+
 	conn       *nats.Conn
 	serializer serializers.Serializer
 }
@@ -121,7 +123,7 @@ func (n *NATS) Write(metrics []telegraf.Metric) error {
 	for _, metric := range metrics {
 		buf, err := n.serializer.Serialize(metric)
 		if err != nil {
-			log.Printf("D! [outputs.nats] Could not serialize metric: %v", err)
+			n.Log.Debugf("Could not serialize metric: %v", err)
 			continue
 		}
 

plugins/outputs/newrelic/newrelic.go

@@ -8,11 +8,12 @@ import (
 	"net/url"
 	"time"
 
+	"github.com/newrelic/newrelic-telemetry-sdk-go/cumulative"
+	"github.com/newrelic/newrelic-telemetry-sdk-go/telemetry"
+
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/config"
 	"github.com/influxdata/telegraf/plugins/outputs"
-	"github.com/newrelic/newrelic-telemetry-sdk-go/cumulative"
-	"github.com/newrelic/newrelic-telemetry-sdk-go/telemetry"
 )
 
 // NewRelic nr structure
@@ -27,7 +28,7 @@ type NewRelic struct {
 	dc          *cumulative.DeltaCalculator
 	savedErrors map[int]interface{}
 	errorCount  int
-	client      http.Client `toml:"-"`
+	client      http.Client
 }
 
 // Description returns a one-sentence description on the Output

plugins/outputs/nsq/nsq.go

@@ -2,19 +2,20 @@ package nsq
 
 import (
 	"fmt"
-	"log"
+
+	"github.com/nsqio/go-nsq"
 
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/plugins/outputs"
 	"github.com/influxdata/telegraf/plugins/serializers"
-	"github.com/nsqio/go-nsq"
 )
 
 type NSQ struct {
 	Server string
 	Topic  string
-	producer *nsq.Producer
+	Log    telegraf.Logger `toml:"-"`
 
+	producer   *nsq.Producer
 	serializer serializers.Serializer
 }
 
@@ -68,13 +69,13 @@ func (n *NSQ) Write(metrics []telegraf.Metric) error {
 	for _, metric := range metrics {
 		buf, err := n.serializer.Serialize(metric)
 		if err != nil {
-			log.Printf("D! [outputs.nsq] Could not serialize metric: %v", err)
+			n.Log.Debugf("Could not serialize metric: %v", err)
 			continue
 		}
 
 		err = n.producer.Publish(n.Topic, buf)
 		if err != nil {
-			return fmt.Errorf("FAILED to send NSQD message: %s", err)
+			return fmt.Errorf("failed to send NSQD message: %s", err)
 		}
 	}
 	return nil