Switch from go-kit/log to log/slog for logging.

Bump github.com/prometheus/exporter-toolkit to v0.14.0.
Bump github.com/prometheus/common to v0.63.0.
Bump github.com/prometheus/client_golang to v1.20.4.
Drops deps for go-kit/log and go-logfmt/logfmt. Update other deps.

The logging system has been replaced with log/slog from the stdlib.  This change is being made across the prometheus ecosystem. The logging output has changed, but the messages and levels remain the same. The ts label for the timestamp has between replaced with time. The caller field has been replaced by the source field. The level field now exposes the log level in capital letters.

See prometheus/exporter-toolkit#240 and prometheus/common#677.

Author: woblerr

backrest/backrest_backup_metrics.go

@@ -1,11 +1,11 @@
 package backrest
 
 import (
+	"log/slog"
 	"strconv"
 	"sync"
 	"time"
 
-	"github.com/go-kit/log"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
 )
@@ -210,7 +210,7 @@ var (
 //   - pgbackrest_backup_annotations
 //
 // And returns info about last backups.
-func getBackupMetrics(stanzaName string, backupRefCount bool, backupData []backup, dbData []db, setUpMetricValueFun setUpMetricValueFunType, logger log.Logger) lastBackupsStruct {
+func getBackupMetrics(stanzaName string, backupRefCount bool, backupData []backup, dbData []db, setUpMetricValueFun setUpMetricValueFunType, logger *slog.Logger) lastBackupsStruct {
 	lastBackups := initLastBackupStruct()
 	// Each backup for current stanza.
 	for _, backup := range backupData {
@@ -407,7 +407,7 @@ func getBackupMetrics(stanzaName string, backupRefCount bool, backupData []backu
 
 // Set backup metrics:
 //   - pgbackrest_backup_databases
-func getBackupDBCountMetrics(maxParallelProcesses int, config, configIncludePath, stanzaName string, backupData []backup, setUpMetricValueFun setUpMetricValueFunType, logger log.Logger) {
+func getBackupDBCountMetrics(maxParallelProcesses int, config, configIncludePath, stanzaName string, backupData []backup, setUpMetricValueFun setUpMetricValueFunType, logger *slog.Logger) {
 	// Create a buffered channel to enforce maximum parallelism.
 	ch := make(chan struct{}, maxParallelProcesses)
 	var wg sync.WaitGroup

backrest/backrest_backup_metrics_test.go

@@ -3,10 +3,10 @@ package backrest
 import (
 	"bytes"
 	"fmt"
+	"log/slog"
 	"strings"
 	"testing"
 
-	"github.com/go-kit/log"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/common/expfmt"
 )
@@ -793,10 +793,10 @@ func TestGetBackupMetricsErrorsAndDebugs(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			resetBackupMetrics()
 			out := &bytes.Buffer{}
-			lc := log.NewLogfmtLogger(out)
+			lc := slog.New(slog.NewTextHandler(out, &slog.HandlerOptions{Level: slog.LevelDebug}))
 			getBackupMetrics(tt.args.stanzaName, tt.args.referenceCountFlag, tt.args.backupData, tt.args.dbData, tt.args.setUpMetricValueFun, lc)
-			errorsOutputCount := strings.Count(out.String(), "level=error")
-			debugsOutputCount := strings.Count(out.String(), "level=debug")
+			errorsOutputCount := strings.Count(out.String(), "level=ERROR")
+			debugsOutputCount := strings.Count(out.String(), "level=DEBUG")
 			if tt.args.errorsCount != errorsOutputCount || tt.args.debugsCount != debugsOutputCount {
 				t.Errorf("\nVariables do not match:\nerrors=%d, debugs=%d\nwant:\nerrors=%d, debugs=%d",
 					tt.args.errorsCount, tt.args.debugsCount,

backrest/backrest_exporter.go

@@ -1,12 +1,11 @@
 package backrest
 
 import (
+	"log/slog"
 	"net/http"
 	"os"
 	"time"
 
-	"github.com/go-kit/log"
-	"github.com/go-kit/log/level"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/prometheus/exporter-toolkit/web"
 )
@@ -31,8 +30,8 @@ func SetPromPortAndPath(flagsConfig web.FlagConfig, endpoint string) {
 }
 
 // StartPromEndpoint run HTTP endpoint
-func StartPromEndpoint(logger log.Logger) {
-	go func(logger log.Logger) {
+func StartPromEndpoint(logger *slog.Logger) {
+	go func(logger *slog.Logger) {
 		http.Handle(webEndpoint, promhttp.Handler())
 		http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
 			w.Write([]byte(`<html>
@@ -47,14 +46,14 @@ func StartPromEndpoint(logger log.Logger) {
 			ReadHeaderTimeout: 5 * time.Second,
 		}
 		if err := web.ListenAndServe(server, &webFlagsConfig, logger); err != nil {
-			level.Error(logger).Log("msg", "Run web endpoint failed", "err", err)
+			logger.Error("Run web endpoint failed", "err", err)
 			os.Exit(1)
 		}
 	}(logger)
 }
 
 // GetPgBackRestInfo get and parse pgBackRest info and set metrics
-func GetPgBackRestInfo(config, configIncludePath, backupType string, stanzas, stanzasExclude []string, backupReferenceCount, backupDBCount, backupDBCountLatest, verboseWAL bool, backupDBCountParallelProcesses int, logger log.Logger) {
+func GetPgBackRestInfo(config, configIncludePath, backupType string, stanzas, stanzasExclude []string, backupReferenceCount, backupDBCount, backupDBCountLatest, verboseWAL bool, backupDBCountParallelProcesses int, logger *slog.Logger) {
 	// To calculate the time elapsed since the last completed full, differential or incremental backup.
 	// For all stanzas values are calculated relative to one value.
 	currentUnixTime := time.Now().Unix()
@@ -78,15 +77,15 @@ func GetPgBackRestInfo(config, configIncludePath, backupType string, stanzas, st
 			stanzaData, err := getAllInfoData(config, configIncludePath, stanza, backupType, logger)
 			if err != nil {
 				getDataSuccessStatus = false
-				level.Error(logger).Log("msg", "Get data from pgBackRest failed", "err", err)
+				logger.Error("Get data from pgBackRest failed", "err", err)
 			}
 			parseStanzaData, err := parseResult(stanzaData)
 			if err != nil {
 				getDataSuccessStatus = false
-				level.Error(logger).Log("msg", "Parse JSON failed", "err", err)
+				logger.Error("Parse JSON failed", "err", err)
 			}
 			if len(parseStanzaData) == 0 {
-				level.Warn(logger).Log("msg", "No backup data returned")
+				logger.Warn("No backup data returned")
 			}
 			// When no specific stanzas set for collecting we can reset the metrics as late as possible.
 			if MetricResetFlag {
@@ -127,12 +126,12 @@ func GetPgBackRestInfo(config, configIncludePath, backupType string, stanzas, st
 			// It is necessary to set zero metric value for this stanza.
 			getDataSuccessStatus = false
 			getExporterStatusMetrics(stanza, getDataSuccessStatus, setUpMetricValue, logger)
-			level.Warn(logger).Log("msg", "Stanza is specified in include and exclude lists", "stanza", stanza)
+			logger.Warn("Stanza is specified in include and exclude lists", "stanza", stanza)
 		}
 	}
 }
 
 // GetExporterInfo set exporter info metric
-func GetExporterInfo(exporterVersion string, logger log.Logger) {
+func GetExporterInfo(exporterVersion string, logger *slog.Logger) {
 	getExporterMetrics(exporterVersion, setUpMetricValue, logger)
 }

backrest/backrest_exporter_metrics.go

@@ -1,7 +1,8 @@
 package backrest
 
 import (
-	"github.com/go-kit/log"
+	"log/slog"
+
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
 )
@@ -21,7 +22,7 @@ var (
 
 // Set exporter info metrics:
 //   - pgbackrest_exporter_info
-func getExporterMetrics(exporterVer string, setUpMetricValueFun setUpMetricValueFunType, logger log.Logger) {
+func getExporterMetrics(exporterVer string, setUpMetricValueFun setUpMetricValueFunType, logger *slog.Logger) {
 	setUpMetric(
 		pgbrExporterInfoMetric,
 		"pgbackrest_exporter_info",
@@ -34,7 +35,7 @@ func getExporterMetrics(exporterVer string, setUpMetricValueFun setUpMetricValue
 
 // Set exporter metrics:
 //   - pgbackrest_exporter_status
-func getExporterStatusMetrics(stanzaName string, getDataStatus bool, setUpMetricValueFun setUpMetricValueFunType, logger log.Logger) {
+func getExporterStatusMetrics(stanzaName string, getDataStatus bool, setUpMetricValueFun setUpMetricValueFunType, logger *slog.Logger) {
 	// If the information is collected for all available stanzas,
 	// the value of the label 'stanza' will be 'all-stanzas',
 	// otherwise the stanza name will be set.

backrest/backrest_exporter_metrics_test.go

@@ -3,10 +3,10 @@ package backrest
 import (
 	"bytes"
 	"fmt"
+	"log/slog"
 	"strings"
 	"testing"
 
-	"github.com/go-kit/log"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/common/expfmt"
 )
@@ -78,10 +78,10 @@ func TestGetExporterInfoErrorsAndDebugs(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			out := &bytes.Buffer{}
-			lc := log.NewLogfmtLogger(out)
+			lc := slog.New(slog.NewTextHandler(out, &slog.HandlerOptions{Level: slog.LevelDebug}))
 			getExporterMetrics(tt.args.exporterVer, tt.args.setUpMetricValueFun, lc)
-			errorsOutputCount := strings.Count(out.String(), "level=error")
-			debugsOutputCount := strings.Count(out.String(), "level=debug")
+			errorsOutputCount := strings.Count(out.String(), "level=ERROR")
+			debugsOutputCount := strings.Count(out.String(), "level=DEBUG")
 			if tt.args.errorsCount != errorsOutputCount || tt.args.debugsCount != debugsOutputCount {
 				t.Errorf("\nVariables do not match:\nerrors=%d, debugs=%d\nwant:\nerrors=%d, debugs=%d",
 					tt.args.errorsCount, tt.args.debugsCount,
@@ -173,10 +173,10 @@ func TestGetExporterStatusErrorsAndDebugs(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			out := &bytes.Buffer{}
-			lc := log.NewLogfmtLogger(out)
+			lc := slog.New(slog.NewTextHandler(out, &slog.HandlerOptions{Level: slog.LevelDebug}))
 			getExporterStatusMetrics(tt.args.stanzaName, tt.args.getDataStatus, tt.args.setUpMetricValueFun, lc)
-			errorsOutputCount := strings.Count(out.String(), "level=error")
-			debugsOutputCount := strings.Count(out.String(), "level=debug")
+			errorsOutputCount := strings.Count(out.String(), "level=ERROR")
+			debugsOutputCount := strings.Count(out.String(), "level=DEBUG")
 			if tt.args.errorsCount != errorsOutputCount || tt.args.debugsCount != debugsOutputCount {
 				t.Errorf("\nVariables do not match:\nerrors=%d, debugs=%d\nwant:\nerrors=%d, debugs=%d",
 					tt.args.errorsCount, tt.args.debugsCount,

backrest/backrest_exporter_test.go

@@ -3,14 +3,13 @@ package backrest
 import (
 	"bytes"
 	"fmt"
+	"log/slog"
 	"os"
 	"os/exec"
 	"strconv"
 	"strings"
 	"testing"
 
-	"github.com/go-kit/log"
-	"github.com/prometheus/common/promlog"
 	"github.com/prometheus/exporter-toolkit/web"
 )
 
@@ -148,7 +147,7 @@ func TestGetPgBackRestInfo(t *testing.T) {
 			execCommand = fakeExecCommand
 			defer func() { execCommand = exec.Command }()
 			out := &bytes.Buffer{}
-			lc := log.NewLogfmtLogger(out)
+			lc := slog.New(slog.NewTextHandler(out, &slog.HandlerOptions{Level: slog.LevelDebug}))
 			GetPgBackRestInfo(
 				tt.args.config,
 				tt.args.configIncludePath,
@@ -195,16 +194,10 @@ func TestExecCommandHelper(t *testing.T) {
 // If it's necessary to capture the logs output in the test,
 // a separate logger is used inside the test.
 // The info logging level is used.
-func getLogger() log.Logger {
-	var err error
-	logLevel := &promlog.AllowedLevel{}
-	err = logLevel.Set("info")
-	if err != nil {
-		panic(err)
-	}
-	promlogConfig := &promlog.Config{}
-	promlogConfig.Level = logLevel
-	return promlog.New(promlogConfig)
+func getLogger() *slog.Logger {
+	return slog.New(slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{
+		Level: slog.LevelInfo,
+	}))
 }
 
 // Helper for displaying web.FlagConfig values test messages.

backrest/backrest_last_backup_metrics.go

@@ -1,11 +1,10 @@
 package backrest
 
 import (
+	"log/slog"
 	"sync"
 	"time"
 
-	"github.com/go-kit/log"
-	"github.com/go-kit/log/level"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
 )
@@ -134,7 +133,7 @@ var (
 //   - pgbackrest_backup_last_repo_delta_map_bytes
 //   - pgbackrest_backup_last_error_status
 //   - pgbackrest_backup_last_annotations
-func getBackupLastMetrics(stanzaName string, lastBackups lastBackupsStruct, currentUnixTime int64, setUpMetricValueFun setUpMetricValueFunType, logger log.Logger) {
+func getBackupLastMetrics(stanzaName string, lastBackups lastBackupsStruct, currentUnixTime int64, setUpMetricValueFun setUpMetricValueFunType, logger *slog.Logger) {
 	for _, backup := range []backupStruct{lastBackups.full, lastBackups.diff, lastBackups.incr} {
 		// Repo backup map size for last backups.
 		setUpMetric(
@@ -265,7 +264,7 @@ func getBackupLastMetrics(stanzaName string, lastBackups lastBackupsStruct, curr
 
 // Set backup metrics:
 //   - pgbackrest_backup_last_databases
-func getBackupLastDBCountMetrics(config, configIncludePath, stanzaName string, lastBackups lastBackupsStruct, setUpMetricValueFun setUpMetricValueFunType, logger log.Logger) {
+func getBackupLastDBCountMetrics(config, configIncludePath, stanzaName string, lastBackups lastBackupsStruct, setUpMetricValueFun setUpMetricValueFunType, logger *slog.Logger) {
 	// For diff and incr run in parallel.
 	var wg sync.WaitGroup
 	// If name for diff backup is equal to full, there is no point in re-receiving data.
@@ -310,8 +309,8 @@ func getBackupLastDBCountMetrics(config, configIncludePath, stanzaName string, l
 	// Try to get info for full backup.
 	parseStanzaDataSpecific, err := getParsedSpecificBackupInfoData(config, configIncludePath, stanzaName, lastBackups.full.backupLabel, logger)
 	if err != nil {
-		level.Error(logger).Log(
-			"msg", "Get data from pgBackRest failed",
+		logger.Error(
+			"Get data from pgBackRest failed",
 			"stanza", stanzaName,
 			"backup", lastBackups.full.backupLabel,
 			"err", err,
@@ -321,7 +320,8 @@ func getBackupLastDBCountMetrics(config, configIncludePath, stanzaName string, l
 		parseStanzaDataSpecific[0].Backup[0].DatabaseRef != nil {
 		metricValue = convertDatabaseRefPointerToFloat(parseStanzaDataSpecific[0].Backup[0].DatabaseRef)
 	} else {
-		level.Warn(logger).Log("msg", "No backup data returned",
+		logger.Warn(
+			"No backup data returned",
 			"stanza", stanzaName,
 			"backup", lastBackups.full.backupLabel,
 		)

backrest/backrest_last_backup_metrics_test.go

@@ -3,10 +3,11 @@ package backrest
 import (
 	"bytes"
 	"fmt"
+	"log/slog"
+	"os"
 	"os/exec"
 	"testing"
 
-	"github.com/go-kit/log"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/common/expfmt"
 )
@@ -284,7 +285,7 @@ pgbackrest_backup_last_databases{backup_type="incr",block_incr="n",stanza="demo"
 			mockDataBackupLast = tt.mockTestDataBackupLast
 			execCommand = fakeExecCommandSpecificDatabase
 			defer func() { execCommand = exec.Command }()
-			lc := log.NewNopLogger()
+			lc := slog.New(slog.NewTextHandler(os.Stdout, nil))
 			getBackupLastDBCountMetrics(tt.args.config, tt.args.configIncludePath, tt.args.stanzaName, tt.args.lastBackups, tt.args.setUpMetricValueFun, lc)
 			reg := prometheus.NewRegistry()
 			reg.MustRegister(