chore!: adopt log/slog, drop go-kit/log

The bulk of this change set was automated by the following script which
is being used to aid in converting the various exporters/projects to use
slog:

https://gist.github.com/tjhop/49f96fb7ebbe55b12deee0b0312d8434

Other changes include:

- updates the statsd_exporter codebase to v0.28.0 to use statsd_exporter
  MetricMapper code that uses log/slog.
- update prometheus codebase to commit
  prometheus/prometheus@911c3ef,
which corresponds to the 3.0 beta 1 release. This is required to use new
prometheus code that uses log/slog.
- refactors/fixes around the tsdb handling in the backfill command for
  current function signatures/usage.
- updates deprecated golangci-lint configs
- enables sloglint linter

Signed-off-by: TJ Hoplock <[email protected]>

Author: tjhop

.golangci.yml

@@ -1,5 +1,5 @@
-run:
-  skip-dirs:
+issues:
+  exclude-dirs:
     - e2e
 
 # Run only staticcheck and goimports for now. Additional linters will be enabled one-by-one.
@@ -8,6 +8,7 @@ linters:
     - errorlint
     - goimports
     - staticcheck
+    - sloglint
   disable-all: true
 
 linters-settings:

cmd/getool/backfill.go

@@ -28,9 +28,8 @@ import (
 	"time"
 
 	"github.com/alecthomas/units"
-	"github.com/go-kit/log"
-	"github.com/go-kit/log/level"
-	"github.com/prometheus/prometheus/pkg/labels"
+	"github.com/prometheus/common/promslog"
+	"github.com/prometheus/prometheus/model/labels"
 	"github.com/prometheus/prometheus/tsdb"
 	tsdb_errors "github.com/prometheus/prometheus/tsdb/errors"
 	"github.com/prometheus/statsd_exporter/pkg/mapper"
@@ -43,7 +42,7 @@ var invalidMetricChars = regexp.MustCompile("[^a-zA-Z0-9_:]")
 func createBlocks(input reader.DBReader, mint, maxt, blockDuration int64, maxSamplesInAppender int, outputDir string, metricMapper *mapper.MetricMapper, strictMatch, humanReadable bool) (returnErr error) {
 	mint = blockDuration * (mint / blockDuration)
 
-	db, err := tsdb.OpenDBReadOnly(outputDir, nil)
+	db, err := tsdb.OpenDBReadOnly(outputDir, "", nil)
 	if err != nil {
 		return err
 	}
@@ -67,7 +66,7 @@ func createBlocks(input reader.DBReader, mint, maxt, blockDuration int64, maxSam
 			// also need to append samples throughout the whole block range. To allow that, we
 			// pretend that the block is twice as large here, but only really add sample in the
 			// original interval later.
-			w, err := tsdb.NewBlockWriter(log.NewNopLogger(), outputDir, 2*blockDuration)
+			w, err := tsdb.NewBlockWriter(promslog.NewNopLogger(), outputDir, 2*blockDuration)
 			if err != nil {
 				return fmt.Errorf("block writer: %w", err)
 			}
@@ -104,7 +103,7 @@ func createBlocks(input reader.DBReader, mint, maxt, blockDuration int64, maxSam
 					return err
 				}
 				for _, point := range points {
-					if _, err := app.Add(l, point.Timestamp, point.Value); err != nil {
+					if _, err := app.Append(0, l, point.Timestamp, point.Value); err != nil {
 						return fmt.Errorf("add sample: %w", err)
 					}
 
@@ -207,8 +206,8 @@ func backfill(maxSamplesInAppender int, inputDir, outputDir, mappingConfig strin
 	if mappingConfig != "" {
 		err := metricMapper.InitFromFile(mappingConfig)
 		if err != nil {
-			logger := log.NewLogfmtLogger(log.NewSyncWriter(os.Stderr))
-			level.Error(logger).Log("msg", "Error loading metric mapping config", "err", err)
+			logger := promslog.New(&promslog.Config{})
+			logger.Error("Error loading metric mapping config", "err", err)
 			return err
 		}
 	}

cmd/getool/backfill_test.go

@@ -27,9 +27,10 @@ import (
 	"time"
 
 	"github.com/go-graphite/go-whisper"
-	"github.com/prometheus/prometheus/pkg/labels"
+	"github.com/prometheus/prometheus/model/labels"
 	"github.com/prometheus/prometheus/storage"
 	"github.com/prometheus/prometheus/tsdb"
+	"github.com/prometheus/prometheus/tsdb/chunkenc"
 	"github.com/stretchr/testify/require"
 )
 
@@ -128,9 +129,9 @@ mappings:
 
 			require.NoError(t, os.MkdirAll(filepath.Join(tmpData, "data", "wal"), 0o777))
 
-			db, err := tsdb.OpenDBReadOnly(filepath.Join(tmpData, "data"), nil)
+			db, err := tsdb.OpenDBReadOnly(filepath.Join(tmpData, "data"), "", nil)
 			require.NoError(t, err)
-			q, err := db.Querier(context.TODO(), math.MinInt64, math.MaxInt64)
+			q, err := db.Querier(math.MinInt64, math.MaxInt64)
 			require.NoError(t, err)
 
 			s := queryAllSeries(t, q)
@@ -160,13 +161,13 @@ type backfillSample struct {
 }
 
 func queryAllSeries(t *testing.T, q storage.Querier) []backfillSample {
-	ss := q.Select(false, nil, labels.MustNewMatcher(labels.MatchRegexp, "", ".*"))
+	ss := q.Select(context.Background(), false, nil, labels.MustNewMatcher(labels.MatchRegexp, "", ".*"))
 	samples := []backfillSample{}
 	for ss.Next() {
 		series := ss.At()
-		it := series.Iterator()
+		it := series.Iterator(nil)
 		require.NoError(t, it.Err())
-		for it.Next() {
+		for it.Next() != chunkenc.ValNone {
 			ts, v := it.At()
 			samples = append(samples, backfillSample{Timestamp: ts, Value: v, Labels: series.Labels()})
 		}

cmd/graphite_exporter/main.go

@@ -17,19 +17,18 @@ import (
 	"bufio"
 	"bytes"
 	"fmt"
+	"log/slog"
 	"net"
 	"net/http"
 	_ "net/http/pprof"
 	"os"
 
 	"github.com/alecthomas/kingpin/v2"
-	"github.com/go-kit/log"
-	"github.com/go-kit/log/level"
 	"github.com/prometheus/client_golang/prometheus"
 	clientVersion "github.com/prometheus/client_golang/prometheus/collectors/version"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
-	"github.com/prometheus/common/promlog"
-	"github.com/prometheus/common/promlog/flag"
+	"github.com/prometheus/common/promslog"
+	"github.com/prometheus/common/promslog/flag"
 	"github.com/prometheus/common/version"
 	"github.com/prometheus/exporter-toolkit/web"
 	"github.com/prometheus/exporter-toolkit/web/kingpinflag"
@@ -57,33 +56,33 @@ func init() {
 	prometheus.MustRegister(clientVersion.NewCollector("graphite_exporter"))
 }
 
-func dumpFSM(mapper *mapper.MetricMapper, dumpFilename string, logger log.Logger) error {
+func dumpFSM(mapper *mapper.MetricMapper, dumpFilename string, logger *slog.Logger) error {
 	if mapper.FSM == nil {
 		return fmt.Errorf("no FSM available to be dumped, possibly because the mapping contains regex patterns")
 	}
 	f, err := os.Create(dumpFilename)
 	if err != nil {
 		return err
 	}
-	level.Info(logger).Log("msg", "Start dumping FSM", "to", dumpFilename)
+	logger.Info("Start dumping FSM", "to", dumpFilename)
 	w := bufio.NewWriter(f)
 	mapper.FSM.DumpFSM(w)
 	w.Flush()
 	f.Close()
-	level.Info(logger).Log("msg", "Finish dumping FSM")
+	logger.Info("Finish dumping FSM")
 	return nil
 }
 
 func main() {
-	promlogConfig := &promlog.Config{}
-	flag.AddFlags(kingpin.CommandLine, promlogConfig)
+	promslogConfig := &promslog.Config{}
+	flag.AddFlags(kingpin.CommandLine, promslogConfig)
 	kingpin.Version(version.Print("graphite_exporter"))
 	kingpin.HelpFlag.Short('h')
 	kingpin.Parse()
-	logger := promlog.New(promlogConfig)
+	logger := promslog.New(promslogConfig)
 
-	level.Info(logger).Log("msg", "Starting graphite_exporter", "version_info", version.Info())
-	level.Info(logger).Log("build_context", version.BuildContext())
+	logger.Info("Starting graphite_exporter", "version_info", version.Info())
+	logger.Info(version.BuildContext())
 
 	http.Handle(*metricsPath, promhttp.Handler())
 	c := collector.NewGraphiteCollector(logger, *strictMatch, *sampleExpiry)
@@ -93,27 +92,27 @@ func main() {
 	if *mappingConfig != "" {
 		err := metricMapper.InitFromFile(*mappingConfig)
 		if err != nil {
-			level.Error(logger).Log("msg", "Error loading metric mapping config", "err", err)
+			logger.Error("Error loading metric mapping config", "err", err)
 			os.Exit(1)
 		}
 	}
 
 	cache, err := getCache(*cacheSize, *cacheType, prometheus.DefaultRegisterer)
 	if err != nil {
-		level.Error(logger).Log("msg", "error initializing mapper cache", "err", err)
+		logger.Error("error initializing mapper cache", "err", err)
 		os.Exit(1)
 	}
 	metricMapper.UseCache(cache)
 
 	if *checkConfig {
-		level.Info(logger).Log("msg", "Configuration check successful, exiting")
+		logger.Info("Configuration check successful, exiting")
 		return
 	}
 
 	if *dumpFSMPath != "" {
 		err := dumpFSM(metricMapper, *dumpFSMPath, logger)
 		if err != nil {
-			level.Error(logger).Log("msg", "Error dumping FSM", "err", err)
+			logger.Error("Error dumping FSM", "err", err)
 			os.Exit(1)
 		}
 	}
@@ -122,14 +121,14 @@ func main() {
 
 	tcpSock, err := net.Listen("tcp", *graphiteAddress)
 	if err != nil {
-		level.Error(logger).Log("msg", "Error binding to TCP socket", "err", err)
+		logger.Error("Error binding to TCP socket", "err", err)
 		os.Exit(1)
 	}
 	go func() {
 		for {
 			conn, err := tcpSock.Accept()
 			if err != nil {
-				level.Error(logger).Log("msg", "Error accepting TCP connection", "err", err)
+				logger.Error("Error accepting TCP connection", "err", err)
 				continue
 			}
 			go func() {
@@ -141,12 +140,12 @@ func main() {
 
 	udpAddress, err := net.ResolveUDPAddr("udp", *graphiteAddress)
 	if err != nil {
-		level.Error(logger).Log("msg", "Error resolving UDP address", "err", err)
+		logger.Error("Error resolving UDP address", "err", err)
 		os.Exit(1)
 	}
 	udpSock, err := net.ListenUDP("udp", udpAddress)
 	if err != nil {
-		level.Error(logger).Log("msg", "Error listening to UDP address", "err", err)
+		logger.Error("Error listening to UDP address", "err", err)
 		os.Exit(1)
 	}
 	go func() {
@@ -155,7 +154,7 @@ func main() {
 			buf := make([]byte, 65536)
 			chars, srcAddress, err := udpSock.ReadFromUDP(buf)
 			if err != nil {
-				level.Error(logger).Log("msg", "Error reading UDP packet", "from", srcAddress, "err", err)
+				logger.Error("Error reading UDP packet", "from", srcAddress, "err", err)
 				continue
 			}
 			go c.ProcessReader(bytes.NewReader(buf[0:chars]))
@@ -179,7 +178,7 @@ func main() {
 
 	server := &http.Server{}
 	if err := web.ListenAndServe(server, toolkitFlags, logger); err != nil {
-		level.Error(logger).Log("err", err)
+		logger.Error("error running HTTP server", "err", err)
 		os.Exit(1)
 	}
 }

collector/collector.go

@@ -17,6 +17,7 @@ import (
 	"bufio"
 	"fmt"
 	"io"
+	"log/slog"
 	"math"
 	_ "net/http/pprof"
 	"regexp"
@@ -25,8 +26,6 @@ import (
 	"sync"
 	"time"
 
-	"github.com/go-kit/log"
-	"github.com/go-kit/log/level"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/statsd_exporter/pkg/mapper"
 )
@@ -40,14 +39,14 @@ type graphiteCollector struct {
 	sampleCh           chan *graphiteSample
 	lineCh             chan string
 	strictMatch        bool
-	logger             log.Logger
+	logger             *slog.Logger
 	tagParseFailures   prometheus.Counter
 	lastProcessed      prometheus.Gauge
 	sampleExpiryMetric prometheus.Gauge
 	sampleExpiry       time.Duration
 }
 
-func NewGraphiteCollector(logger log.Logger, strictMatch bool, sampleExpiry time.Duration) *graphiteCollector {
+func NewGraphiteCollector(logger *slog.Logger, strictMatch bool, sampleExpiry time.Duration) *graphiteCollector {
 	c := &graphiteCollector{
 		sampleCh:    make(chan *graphiteSample),
 		lineCh:      make(chan string),
@@ -128,19 +127,19 @@ func (c *graphiteCollector) parseMetricNameAndTags(name string) (string, prometh
 
 func (c *graphiteCollector) processLine(line string) {
 	line = strings.TrimSpace(line)
-	level.Debug(c.logger).Log("msg", "Incoming line", "line", line)
+	c.logger.Debug("Incoming line", "line", line)
 
 	parts := strings.Split(line, " ")
 	if len(parts) != 3 {
-		level.Info(c.logger).Log("msg", "Invalid part count", "parts", len(parts), "line", line)
+		c.logger.Info("Invalid part count", "parts", len(parts), "line", line)
 		return
 	}
 
 	originalName := parts[0]
 
 	parsedName, labels, err := c.parseMetricNameAndTags(originalName)
 	if err != nil {
-		level.Debug(c.logger).Log("msg", "Invalid tags", "line", line, "err", err.Error())
+		c.logger.Debug("Invalid tags", "line", line, "err", err.Error())
 	}
 
 	mapping, mappingLabels, mappingPresent := c.mapper.GetMapping(parsedName, mapper.MetricTypeGauge)
@@ -163,12 +162,12 @@ func (c *graphiteCollector) processLine(line string) {
 
 	value, err := strconv.ParseFloat(parts[1], 64)
 	if err != nil {
-		level.Info(c.logger).Log("msg", "Invalid value", "line", line)
+		c.logger.Info("Invalid value", "line", line)
 		return
 	}
 	timestamp, err := strconv.ParseFloat(parts[2], 64)
 	if err != nil {
-		level.Info(c.logger).Log("msg", "Invalid timestamp", "line", line)
+		c.logger.Info("Invalid timestamp", "line", line)
 		return
 	}
 	sample := graphiteSample{
@@ -180,7 +179,7 @@ func (c *graphiteCollector) processLine(line string) {
 		Help:         fmt.Sprintf("Graphite metric %s", name),
 		Timestamp:    time.Unix(int64(timestamp), int64(math.Mod(timestamp, 1.0)*1e9)),
 	}
-	level.Debug(c.logger).Log("msg", "Processing sample", "sample", sample)
+	c.logger.Debug("Processing sample", "sample", sample)
 	c.lastProcessed.Set(float64(time.Now().UnixNano()) / 1e9)
 	c.sampleCh <- &sample
 }

collector/collector_benchmark_test.go

@@ -19,13 +19,13 @@ import (
 	"testing"
 	"time"
 
-	"github.com/go-kit/log"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/common/promslog"
 	"github.com/prometheus/statsd_exporter/pkg/mapper"
 )
 
 var (
-	logger = log.NewNopLogger()
+	logger = promslog.NewNopLogger()
 	c      = NewGraphiteCollector(logger, false, 5*time.Minute)
 
 	now = time.Now()

collector/collector_test.go

@@ -18,14 +18,14 @@ import (
 	"testing"
 	"time"
 
-	"github.com/go-kit/log"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/common/promslog"
 	"github.com/prometheus/statsd_exporter/pkg/mapper"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestParseNameAndTags(t *testing.T) {
-	logger := log.NewNopLogger()
+	logger := promslog.NewNopLogger()
 	c := NewGraphiteCollector(logger, false, 5*time.Minute)
 	type testCase struct {
 		line       string
@@ -204,7 +204,7 @@ func TestProcessLine(t *testing.T) {
 		},
 	}
 
-	c := NewGraphiteCollector(log.NewNopLogger(), false, 5*time.Minute)
+	c := NewGraphiteCollector(promslog.NewNopLogger(), false, 5*time.Minute)
 
 	for _, testCase := range testCases {
 		if testCase.mappingPresent {