Move from github.com/go-kit/log to log/slog

Signed-off-by: Mario Trangoni <[email protected]>

.golangci.yml

@@ -28,8 +28,7 @@ linters-settings:
           - $gostd
           - github.com/mjtrangoni/flexlm_exporter
           - github.com/prometheus/client_golang
-          - github.com/go-kit/log
-          - github.com/prometheus/common/promlog
+          - github.com/prometheus/common/promslog
           - github.com/prometheus/common/version
           - github.com/prometheus/exporter-toolkit/web
           - github.com/alecthomas/kingpin/v2

collector/collector.go

@@ -16,14 +16,14 @@
 package collector
 
 import (
+	"errors"
 	"fmt"
+	"log/slog"
 	"strconv"
 	"sync"
 	"time"
 
 	kingpin "github.com/alecthomas/kingpin/v2"
-	"github.com/go-kit/log"
-	"github.com/go-kit/log/level"
 	"github.com/prometheus/client_golang/prometheus"
 )
 
@@ -57,14 +57,14 @@ const (
 )
 
 var (
-	factories              = make(map[string]func(logger log.Logger) (Collector, error))
+	factories              = make(map[string]func(logger *slog.Logger) (Collector, error))
 	initiatedCollectorsMtx = sync.Mutex{}
 	initiatedCollectors    = make(map[string]Collector)
 	collectorState         = make(map[string]*bool)
 	forcedCollectors       = map[string]bool{} // collectors which have been explicitly enabled or disabled
 )
 
-func registerCollector(collector string, isDefaultEnabled bool, factory func(logger log.Logger) (Collector, error)) {
+func registerCollector(collector string, isDefaultEnabled bool, factory func(logger *slog.Logger) (Collector, error)) {
 	var helpDefaultState string
 	if isDefaultEnabled {
 		helpDefaultState = "enabled"
@@ -85,7 +85,7 @@ func registerCollector(collector string, isDefaultEnabled bool, factory func(log
 // FlexlmCollector implements the prometheus.Collector interface.
 type FlexlmCollector struct {
 	Collectors map[string]Collector
-	logger     log.Logger
+	logger     *slog.Logger
 }
 
 // collectorFlagAction generates a new action function for the given collector
@@ -102,10 +102,10 @@ func collectorFlagAction(collector string) func(ctx *kingpin.ParseContext) error
 	}
 }
 
-//revive:enable:unused-parameter
-
 // NewFlexlmCollector creates a new FlexlmCollector.
-func NewFlexlmCollector(logger log.Logger, filters ...string) (*FlexlmCollector, error) {
+//
+//revive:enable:unused-parameter
+func NewFlexlmCollector(logger *slog.Logger, filters ...string) (*FlexlmCollector, error) {
 	f := make(map[string]bool)
 
 	for _, filter := range filters {
@@ -132,7 +132,7 @@ func NewFlexlmCollector(logger log.Logger, filters ...string) (*FlexlmCollector,
 		if collector, ok := initiatedCollectors[key]; ok {
 			collectors[key] = collector
 		} else {
-			collector, err := factories[key](log.With(logger, "collector", key))
+			collector, err := factories[key](logger.With("collector", key))
 			if err != nil {
 				return nil, err
 			}
@@ -168,19 +168,23 @@ func (n FlexlmCollector) Collect(ch chan<- prometheus.Metric) {
 	wg.Wait()
 }
 
-func execute(name string, c Collector, ch chan<- prometheus.Metric, logger log.Logger) {
+func execute(name string, c Collector, ch chan<- prometheus.Metric, logger *slog.Logger) {
 	var success float64
 
 	begin := time.Now()
 	err := c.Update(ch)
 	duration := time.Since(begin)
 
 	if err != nil {
-		level.Error(logger).Log(name, "collector failed after:", duration.Seconds(), ":", err)
+		if IsNoDataError(err) {
+			logger.Debug("collector returned no data", "name", name, "duration_seconds", duration.Seconds(), "err", err)
+		} else {
+			logger.Error("collector failed", "name", name, "duration_seconds", duration.Seconds(), "err", err)
+		}
 
 		success = 0
 	} else {
-		level.Debug(logger).Log("OK:", name, "collector succeeded after:", duration.Seconds())
+		logger.Debug("collector succeeded", "name", name, "duration_seconds", duration.Seconds())
 
 		success = 1
 	}
@@ -193,3 +197,10 @@ type Collector interface {
 	// Get new metrics and expose them via prometheus registry.
 	Update(ch chan<- prometheus.Metric) error
 }
+
+// ErrNoData indicates the collector found no data to collect, but had no other error.
+var ErrNoData = errors.New("collector returned no data")
+
+func IsNoDataError(err error) bool {
+	return err == ErrNoData
+}

collector/lmstat.go

@@ -17,6 +17,7 @@ import (
 	"bytes"
 	"encoding/csv"
 	"fmt"
+	"log/slog"
 	"os"
 	"os/exec"
 	"regexp"
@@ -25,8 +26,6 @@ import (
 	"sync"
 	"time"
 
-	"github.com/go-kit/log"
-	"github.com/go-kit/log/level"
 	"github.com/mjtrangoni/flexlm_exporter/config"
 	"github.com/prometheus/client_golang/prometheus"
 )
@@ -41,7 +40,7 @@ type lmstatCollector struct {
 	lmstatFeatureReservGroups      *prometheus.Desc
 	lmstatFeatureReservHost        *prometheus.Desc
 	lmstatFeatureIssued            *prometheus.Desc
-	logger                         log.Logger
+	logger                         *slog.Logger
 }
 
 // LicenseConfig is going to be read once in main, and then used here.
@@ -56,7 +55,7 @@ func init() {
 }
 
 // NewLmstatCollector returns a new Collector exposing lmstat license stats.
-func NewLmstatCollector(logger log.Logger) (Collector, error) {
+func NewLmstatCollector(logger *slog.Logger) (Collector, error) {
 	return &lmstatCollector{
 		lmstatInfo: prometheus.NewDesc(
 			prometheus.BuildFQName(namespace, "lmstat", "info"),
@@ -138,10 +137,10 @@ func contains(slice []string, item string) bool {
 }
 
 // execute lmutil utility.
-func lmutilOutput(logger log.Logger, args ...string) ([]byte, error) {
+func lmutilOutput(logger *slog.Logger, args ...string) ([]byte, error) {
 	_, err := os.Stat(*lmutilPath)
 	if os.IsNotExist(err) {
-		level.Error(logger).Log("err", *lmutilPath, "missing")
+		logger.Error("err", *lmutilPath, "missing")
 		os.Exit(1)
 	}
 
@@ -273,7 +272,7 @@ func parseLmstatLicenseInfoVendor(outStr [][]string) map[string]*vendor {
 	return vendors
 }
 
-func parseLmstatLicenseInfoFeature(outStr [][]string, logger log.Logger) (map[string]*feature,
+func parseLmstatLicenseInfoFeature(outStr [][]string, logger *slog.Logger) (map[string]*feature,
 	map[string]map[string][]*featureUserUsed, map[string]map[string]float64, map[string]map[string]float64) {
 	features := make(map[string]*feature)
 	licUsersByFeature := make(map[string]map[string][]*featureUserUsed)
@@ -289,14 +288,14 @@ func parseLmstatLicenseInfoFeature(outStr [][]string, logger log.Logger) (map[st
 
 			issued, err := strconv.Atoi(matches[2])
 			if err != nil {
-				level.Error(logger).Log("could not convert", matches[2], "to integer:", err)
+				logger.Error("err", "could not convert", matches[2], "to integer:", err)
 			}
 
 			featureName = matches[1]
 
 			used, err := strconv.Atoi(matches[3])
 			if err != nil {
-				level.Error(logger).Log("could not convert", matches[3], "to integer:", err)
+				logger.Error("err", "could not convert", matches[3], "to integer:", err)
 			}
 
 			features[featureName] = &feature{
@@ -312,7 +311,7 @@ func parseLmstatLicenseInfoFeature(outStr [][]string, logger log.Logger) (map[st
 			username := matches["user"]
 
 			if strings.TrimSpace(username) == "" {
-				level.Debug(logger).Log("username couldn't be found for '", lineJoined,
+				logger.Debug("username couldn't be found for '", lineJoined,
 					"', using lmutilLicenseFeatureUsageUser2Regex.")
 
 				matches = reSubMatchMap(lmutilLicenseFeatureUsageUser2Regex, lineJoined)
@@ -337,7 +336,7 @@ func parseLmstatLicenseInfoFeature(outStr [][]string, logger log.Logger) (map[st
 			if matches["licenses"] != "" {
 				licUsed, err := strconv.Atoi(matches["licenses"])
 				if err != nil {
-					level.Error(logger).Log("could not convert", matches["licenses"], "to integer:", err)
+					logger.Error("err", "could not convert", matches["licenses"], "to integer:", err)
 				}
 
 				for i := range licUsersByFeature[featureName][username] {
@@ -361,7 +360,7 @@ func parseLmstatLicenseInfoFeature(outStr [][]string, logger log.Logger) (map[st
 
 			groupReserv, err := strconv.Atoi(matches[2])
 			if err != nil {
-				level.Error(logger).Log("could not convert", matches[1], "to integer:", err)
+				logger.Error("err", "could not convert", matches[1], "to integer:", err)
 			}
 
 			reservGroupByFeature[featureName][matches[4]] = float64(groupReserv)
@@ -374,7 +373,7 @@ func parseLmstatLicenseInfoFeature(outStr [][]string, logger log.Logger) (map[st
 			hostReserv, err := strconv.Atoi(matches[2])
 
 			if err != nil {
-				level.Error(logger).Log("could not convert", matches[1], "to integer:", err)
+				logger.Error("err", "could not convert", matches[1], "to integer:", err)
 			}
 
 			reservHostByFeature[featureName][matches[4]] = float64(hostReserv)
@@ -555,7 +554,7 @@ func reSubMatchMap(r *regexp.Regexp, str string) map[string]string {
 	return subMatchMap
 }
 
-func convertLmstatTimeToUnixTime(lmtime string, logger log.Logger) time.Time {
+func convertLmstatTimeToUnixTime(lmtime string, logger *slog.Logger) time.Time {
 	matches := reSubMatchMap(lmutilTimeRegex, lmtime)
 
 	// current time and offset (lmstat outputs the time for the current time zone of the server where it is executed)
@@ -574,7 +573,7 @@ func convertLmstatTimeToUnixTime(lmtime string, logger log.Logger) time.Time {
 		ltime = ltime.Add(-time.Duration(offset) * time.Second)
 
 		if err != nil {
-			level.Error(logger).Log("could not convert", ltime, "to unix time:", err)
+			logger.Error("err", "could not convert", ltime, "to unix time:", err)
 
 			// fallback, just return the current time in case of errors
 			return ctime

collector/lmstat_feature_exp.go

@@ -15,15 +15,14 @@ package collector
 
 import (
 	"fmt"
+	"log/slog"
 	"math"
 	"sort"
 	"strconv"
 	"strings"
 	"sync"
 	"time"
 
-	"github.com/go-kit/log"
-	"github.com/go-kit/log/level"
 	"github.com/mjtrangoni/flexlm_exporter/config"
 	"github.com/prometheus/client_golang/prometheus"
 	"golang.org/x/text/cases"
@@ -39,7 +38,7 @@ const (
 type lmstatFeatureExpCollector struct {
 	lmstatFeatureExp     *prometheus.Desc
 	lmstatFeatureAggrExp *prometheus.Desc
-	logger               log.Logger
+	logger               *slog.Logger
 }
 
 func init() {
@@ -49,7 +48,7 @@ func init() {
 
 // NewLmstatFeatureExpCollector returns a new Collector exposing lmstat license
 // feature expiration date.
-func NewLmstatFeatureExpCollector(logger log.Logger) (Collector, error) {
+func NewLmstatFeatureExpCollector(logger *slog.Logger) (Collector, error) {
 	return &lmstatFeatureExpCollector{
 		lmstatFeatureExp: prometheus.NewDesc(
 			prometheus.BuildFQName(namespace, "feature",
@@ -80,7 +79,7 @@ func (c *lmstatFeatureExpCollector) Update(ch chan<- prometheus.Metric) error {
 	return nil
 }
 
-func parseLmstatLicenseFeatureExpDate(outStr [][]string, logger log.Logger) map[int]*featureExp {
+func parseLmstatLicenseFeatureExpDate(outStr [][]string, logger *slog.Logger) map[int]*featureExp {
 	var (
 		expires     float64
 		index       int
@@ -106,7 +105,7 @@ func parseLmstatLicenseFeatureExpDate(outStr [][]string, logger log.Logger) map[
 			vendorIndex = 4
 		}
 
-		level.Debug(logger).Log(matches)
+		logger.Debug("debug", "matches", matches)
 		// Parse date, month has to be capitalized.
 		slice := strings.Split(matches[expIndex], "-")
 		if len(slice) > lenghtOne {
@@ -126,7 +125,7 @@ func parseLmstatLicenseFeatureExpDate(outStr [][]string, logger log.Logger) map[
 				fmt.Sprintf("%s-%s-%s", day,
 					cases.Title(language.English).String(month), year))
 			if err != nil {
-				level.Error(logger).Log("could not convert to date:", err)
+				logger.Error("err", "could not convert to date:", err)
 			}
 
 			if expireDate.Unix() <= 0 {

collector/lmstat_feature_exp_test.go

@@ -19,7 +19,7 @@ import (
 	"os"
 	"testing"
 
-	"github.com/go-kit/log"
+	"github.com/prometheus/common/promslog"
 )
 
 const (
@@ -43,7 +43,8 @@ func TestParseLmstatLicenseFeatureExpDate1(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	featuresExp := parseLmstatLicenseFeatureExpDate(dataStr, log.NewNopLogger())
+	logger := promslog.New(&promslog.Config{})
+	featuresExp := parseLmstatLicenseFeatureExpDate(dataStr, logger)
 	found := false
 
 	for index, feature := range featuresExp {
@@ -119,7 +120,8 @@ func TestParseLmstatLicenseFeatureExpDate2(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	featuresExp := parseLmstatLicenseFeatureExpDate(dataStr, log.NewNopLogger())
+	logger := promslog.New(&promslog.Config{})
+	featuresExp := parseLmstatLicenseFeatureExpDate(dataStr, logger)
 	found := false
 
 	for index, feature := range featuresExp {

collector/lmstat_test.go

@@ -20,7 +20,7 @@ import (
 	"testing"
 	"time"
 
-	"github.com/go-kit/log"
+	"github.com/prometheus/common/promslog"
 )
 
 const (
@@ -210,7 +210,9 @@ func TestParseLmstatLicenseInfoFeature(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	features, licUsersByFeature, reservGroupByFeature, reservHostByFeature := parseLmstatLicenseInfoFeature(dataStr, log.NewNopLogger())
+	logger := promslog.New(&promslog.Config{})
+	features, licUsersByFeature, reservGroupByFeature, reservHostByFeature := parseLmstatLicenseInfoFeature(dataStr, logger)
+
 	for name, info := range features {
 		if name == "feature11" {
 			if info.issued != 16384 || info.used != 80 {
@@ -358,7 +360,9 @@ func TestParseLmstatLicenseInfoUserSince(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	_, licUsersByFeature, _, _ := parseLmstatLicenseInfoFeature(dataStr, log.NewNopLogger())
+	logger := promslog.New(&promslog.Config{})
+	_, licUsersByFeature, _, _ := parseLmstatLicenseInfoFeature(dataStr,
+		logger)
 
 	// the year does not matter in this case, since lmstat omits the year information
 	ctime := time.Now()

config/config.go

@@ -16,11 +16,10 @@ package config
 
 import (
 	"fmt"
+	"log/slog"
 	"os"
 	"path/filepath"
 
-	"github.com/go-kit/log"
-	"github.com/go-kit/log/level"
 	"gopkg.in/yaml.v3"
 )
 
@@ -44,9 +43,9 @@ type Configuration struct {
 }
 
 // Load parses the YAML file.
-func Load(filename string, logger log.Logger) (Configuration, error) {
-	level.Info(logger).Log("msg", "Loading license config file:")
-	level.Info(logger).Log(" - ", filename)
+func Load(filename string, logger *slog.Logger) (Configuration, error) {
+	logger.Info("Loading license config file:")
+	logger.Info(filename)
 
 	bytes, err := os.ReadFile(filepath.Clean(filename))
 	if err != nil {
@@ -58,7 +57,7 @@ func Load(filename string, logger log.Logger) (Configuration, error) {
 	err = yaml.Unmarshal(bytes, &c)
 
 	if err != nil {
-		level.Error(logger).Log("Couldn't load config file: ", err)
+		logger.Error(fmt.Sprintf("Couldn't load config file: %v", err))
 		return c, err
 	}