Linter fixes for plugins/inputs/[de]* (#9379)

(cherry picked from commit 9a79491)

.golangci.yml

@@ -50,7 +50,7 @@ linters-settings:
       - name: error-return
       - name: error-strings
       - name: errorf
-      - name: flag-parameter
+#      - name: flag-parameter #disable for now
       - name: function-result-limit
         arguments: [ 3 ]
       - name: identical-branches

plugins/inputs/dcos/client.go

@@ -156,7 +156,7 @@ func (c *ClusterClient) Login(ctx context.Context, sa *ServiceAccount) (*AuthTok
 		return nil, err
 	}
 
-	loc := c.url("/acs/api/v1/auth/login")
+	loc := c.toURL("/acs/api/v1/auth/login")
 	req, err := http.NewRequest("POST", loc, bytes.NewBuffer(octets))
 	if err != nil {
 		return nil, err
@@ -208,7 +208,7 @@ func (c *ClusterClient) Login(ctx context.Context, sa *ServiceAccount) (*AuthTok
 
 func (c *ClusterClient) GetSummary(ctx context.Context) (*Summary, error) {
 	summary := &Summary{}
-	err := c.doGet(ctx, c.url("/mesos/master/state-summary"), summary)
+	err := c.doGet(ctx, c.toURL("/mesos/master/state-summary"), summary)
 	if err != nil {
 		return nil, err
 	}
@@ -220,7 +220,7 @@ func (c *ClusterClient) GetContainers(ctx context.Context, node string) ([]Conta
 	list := []string{}
 
 	path := fmt.Sprintf("/system/v1/agent/%s/metrics/v0/containers", node)
-	err := c.doGet(ctx, c.url(path), &list)
+	err := c.doGet(ctx, c.toURL(path), &list)
 	if err != nil {
 		return nil, err
 	}
@@ -233,10 +233,10 @@ func (c *ClusterClient) GetContainers(ctx context.Context, node string) ([]Conta
 	return containers, nil
 }
 
-func (c *ClusterClient) getMetrics(ctx context.Context, url string) (*Metrics, error) {
+func (c *ClusterClient) getMetrics(ctx context.Context, address string) (*Metrics, error) {
 	metrics := &Metrics{}
 
-	err := c.doGet(ctx, url, metrics)
+	err := c.doGet(ctx, address, metrics)
 	if err != nil {
 		return nil, err
 	}
@@ -246,21 +246,21 @@ func (c *ClusterClient) getMetrics(ctx context.Context, url string) (*Metrics, e
 
 func (c *ClusterClient) GetNodeMetrics(ctx context.Context, node string) (*Metrics, error) {
 	path := fmt.Sprintf("/system/v1/agent/%s/metrics/v0/node", node)
-	return c.getMetrics(ctx, c.url(path))
+	return c.getMetrics(ctx, c.toURL(path))
 }
 
 func (c *ClusterClient) GetContainerMetrics(ctx context.Context, node, container string) (*Metrics, error) {
 	path := fmt.Sprintf("/system/v1/agent/%s/metrics/v0/containers/%s", node, container)
-	return c.getMetrics(ctx, c.url(path))
+	return c.getMetrics(ctx, c.toURL(path))
 }
 
 func (c *ClusterClient) GetAppMetrics(ctx context.Context, node, container string) (*Metrics, error) {
 	path := fmt.Sprintf("/system/v1/agent/%s/metrics/v0/containers/%s/app", node, container)
-	return c.getMetrics(ctx, c.url(path))
+	return c.getMetrics(ctx, c.toURL(path))
 }
 
-func createGetRequest(url string, token string) (*http.Request, error) {
-	req, err := http.NewRequest("GET", url, nil)
+func createGetRequest(address string, token string) (*http.Request, error) {
+	req, err := http.NewRequest("GET", address, nil)
 	if err != nil {
 		return nil, err
 	}
@@ -273,8 +273,8 @@ func createGetRequest(url string, token string) (*http.Request, error) {
 	return req, nil
 }
 
-func (c *ClusterClient) doGet(ctx context.Context, url string, v interface{}) error {
-	req, err := createGetRequest(url, c.token)
+func (c *ClusterClient) doGet(ctx context.Context, address string, v interface{}) error {
+	req, err := createGetRequest(address, c.token)
 	if err != nil {
 		return err
 	}
@@ -304,7 +304,7 @@ func (c *ClusterClient) doGet(ctx context.Context, url string, v interface{}) er
 
 	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
 		return &APIError{
-			URL:        url,
+			URL:        address,
 			StatusCode: resp.StatusCode,
 			Title:      resp.Status,
 		}
@@ -318,10 +318,10 @@ func (c *ClusterClient) doGet(ctx context.Context, url string, v interface{}) er
 	return err
 }
 
-func (c *ClusterClient) url(path string) string {
-	url := *c.clusterURL
-	url.Path = path
-	return url.String()
+func (c *ClusterClient) toURL(path string) string {
+	clusterURL := *c.clusterURL
+	clusterURL.Path = path
+	return clusterURL.String()
 }
 
 func (c *ClusterClient) createLoginToken(sa *ServiceAccount) (string, error) {

plugins/inputs/dcos/dcos.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	jwt "github.com/dgrijalva/jwt-go/v4"
+
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/config"
 	"github.com/influxdata/telegraf/filter"
@@ -352,13 +353,13 @@ func (d *DCOS) createClient() (Client, error) {
 		return nil, err
 	}
 
-	url, err := url.Parse(d.ClusterURL)
+	address, err := url.Parse(d.ClusterURL)
 	if err != nil {
 		return nil, err
 	}
 
 	client := NewClusterClient(
-		url,
+		address,
 		time.Duration(d.ResponseTimeout),
 		d.MaxConnections,
 		tlsCfg,

plugins/inputs/directory_monitor/directory_monitor.go

@@ -2,27 +2,27 @@ package directory_monitor
 
 import (
 	"bufio"
+	"compress/gzip"
 	"context"
 	"errors"
 	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
 	"regexp"
+	"sync"
 	"time"
 
+	"golang.org/x/sync/semaphore"
+	"gopkg.in/djherbis/times.v1"
+
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/config"
 	"github.com/influxdata/telegraf/plugins/inputs"
 	"github.com/influxdata/telegraf/plugins/parsers"
 	"github.com/influxdata/telegraf/plugins/parsers/csv"
 	"github.com/influxdata/telegraf/selfstat"
-	"golang.org/x/sync/semaphore"
-	"gopkg.in/djherbis/times.v1"
-
-	"compress/gzip"
-	"io"
-	"io/ioutil"
-	"os"
-	"path/filepath"
-	"sync"
 )
 
 const sampleConfig = `
@@ -263,9 +263,7 @@ func (monitor *DirectoryMonitor) parseFile(parser parsers.Parser, reader io.Read
 		if err != nil {
 			return err
 		}
-		if firstLine {
-			firstLine = false
-		}
+		firstLine = false
 
 		if err := monitor.sendMetrics(metrics); err != nil {
 			return err

plugins/inputs/directory_monitor/directory_monitor_test.go

@@ -8,9 +8,10 @@ import (
 	"path/filepath"
 	"testing"
 
+	"github.com/stretchr/testify/require"
+
 	"github.com/influxdata/telegraf/plugins/parsers"
 	"github.com/influxdata/telegraf/testutil"
-	"github.com/stretchr/testify/require"
 )
 
 func TestCSVGZImport(t *testing.T) {
@@ -77,8 +78,9 @@ func TestCSVGZImport(t *testing.T) {
 
 	// File should have gone back to the test directory, as we configured.
 	_, err = os.Stat(filepath.Join(finishedDirectory, testCsvFile))
-	_, err = os.Stat(filepath.Join(finishedDirectory, testCsvGzFile))
+	require.NoError(t, err)
 
+	_, err = os.Stat(filepath.Join(finishedDirectory, testCsvGzFile))
 	require.NoError(t, err)
 }
 

plugins/inputs/disk/disk.go

@@ -13,7 +13,7 @@ type DiskStats struct {
 	ps system.PS
 
 	// Legacy support
-	Mountpoints []string `toml:"mountpoints"`
+	LegacyMountPoints []string `toml:"mountpoints"`
 
 	MountPoints []string `toml:"mount_points"`
 	IgnoreFS    []string `toml:"ignore_fs"`
@@ -38,8 +38,8 @@ func (ds *DiskStats) SampleConfig() string {
 
 func (ds *DiskStats) Gather(acc telegraf.Accumulator) error {
 	// Legacy support:
-	if len(ds.Mountpoints) != 0 {
-		ds.MountPoints = ds.Mountpoints
+	if len(ds.LegacyMountPoints) != 0 {
+		ds.MountPoints = ds.LegacyMountPoints
 	}
 
 	disks, partitions, err := ds.ps.DiskUsage(ds.MountPoints, ds.IgnoreFS)