promtool: add a "tsdb dump-openmetrics" to dump in OpemMetrics format.

This closes the loop, as the output can be fed into "tsdb create-blocks-from openmetrics"

Native histograms are not supported.

Signed-off-by: machine424 <ayoubmrini424@gmail.com>

cmd/promtool/main.go

@@ -239,6 +239,12 @@ func main() {
 	dumpMaxTime := tsdbDumpCmd.Flag("max-time", "Maximum timestamp to dump.").Default(strconv.FormatInt(math.MaxInt64, 10)).Int64()
 	dumpMatch := tsdbDumpCmd.Flag("match", "Series selector. Can be specified multiple times.").Default("{__name__=~'(?s:.*)'}").Strings()
 
+	tsdbDumpOpenMetricsCmd := tsdbCmd.Command("dump-openmetrics", "[Experimental] Dump samples from a TSDB into OpenMetrics format. Native histograms are not dumped.")
+	dumpOpenMetricsPath := tsdbDumpOpenMetricsCmd.Arg("db path", "Database path (default is "+defaultDBPath+").").Default(defaultDBPath).String()
+	dumpOpenMetricsMinTime := tsdbDumpOpenMetricsCmd.Flag("min-time", "Minimum timestamp to dump.").Default(strconv.FormatInt(math.MinInt64, 10)).Int64()
+	dumpOpenMetricsMaxTime := tsdbDumpOpenMetricsCmd.Flag("max-time", "Maximum timestamp to dump.").Default(strconv.FormatInt(math.MaxInt64, 10)).Int64()
+	dumpOpenMetricsMatch := tsdbDumpOpenMetricsCmd.Flag("match", "Series selector. Can be specified multiple times.").Default("{__name__=~'(?s:.*)'}").Strings()
+
 	importCmd := tsdbCmd.Command("create-blocks-from", "[Experimental] Import samples from input and produce TSDB blocks. Please refer to the storage docs for more details.")
 	importHumanReadable := importCmd.Flag("human-readable", "Print human readable values.").Short('r').Bool()
 	importQuiet := importCmd.Flag("quiet", "Do not print created blocks.").Short('q').Bool()
@@ -390,7 +396,9 @@ func main() {
 		os.Exit(checkErr(listBlocks(*listPath, *listHumanReadable)))
 
 	case tsdbDumpCmd.FullCommand():
-		os.Exit(checkErr(dumpSamples(ctx, *dumpPath, *dumpMinTime, *dumpMaxTime, *dumpMatch)))
+		os.Exit(checkErr(dumpSamples(ctx, *dumpPath, *dumpMinTime, *dumpMaxTime, *dumpMatch, formatSeriesSet)))
+	case tsdbDumpOpenMetricsCmd.FullCommand():
+		os.Exit(checkErr(dumpSamples(ctx, *dumpOpenMetricsPath, *dumpOpenMetricsMinTime, *dumpOpenMetricsMaxTime, *dumpOpenMetricsMatch, formatSeriesSetOpenMetrics)))
 	// TODO(aSquare14): Work on adding support for custom block size.
 	case openMetricsImportCmd.FullCommand():
 		os.Exit(backfillOpenMetrics(*importFilePath, *importDBPath, *importHumanReadable, *importQuiet, *maxBlockDuration))

cmd/promtool/testdata/dump-openmetrics-roundtrip-test.prom

@@ -0,0 +1,15 @@
+my_histogram_bucket{instance="localhost:8000",job="example2",le="+Inf"} 1.0267820369e+10 1700215884.373
+my_histogram_bucket{instance="localhost:8000",job="example2",le="+Inf"} 1.026872507e+10 1700215889.373
+my_histogram_bucket{instance="localhost:8000",job="example2",le="0.01"} 0 1700215884.373
+my_histogram_bucket{instance="localhost:8000",job="example2",le="0.01"} 0 1700215889.373
+my_histogram_count{instance="localhost:8000",job="example2"} 1.0267820369e+10 1700215884.373
+my_histogram_count{instance="localhost:8000",job="example2"} 1.026872507e+10 1700215889.373
+my_summary_count{instance="localhost:8000",job="example5"} 9.518161497e+09 1700211684.981
+my_summary_count{instance="localhost:8000",job="example5"} 9.519048034e+09 1700211689.984
+my_summary_sum{instance="localhost:8000",job="example5"} 5.2349889185e+10 1700211684.981
+my_summary_sum{instance="localhost:8000",job="example5"} 5.2354761848e+10 1700211689.984
+up{instance="localhost:8000",job="example2"} 1 1700226034.330
+up{instance="localhost:8000",job="example2"} 1 1700226094.329
+up{instance="localhost:8000",job="example3"} 1 1700210681.366
+up{instance="localhost:8000",job="example3"} 1 1700210686.366
+# EOF

cmd/promtool/testdata/dump-openmetrics-test.prom

@@ -0,0 +1,11 @@
+my_counter{baz="abc",foo="bar"} 1 0.000
+my_counter{baz="abc",foo="bar"} 2 60.000
+my_counter{baz="abc",foo="bar"} 3 120.000
+my_counter{baz="abc",foo="bar"} 4 180.000
+my_counter{baz="abc",foo="bar"} 5 240.000
+my_gauge{abc="baz",bar="foo"} 9 0.000
+my_gauge{abc="baz",bar="foo"} 8 60.000
+my_gauge{abc="baz",bar="foo"} 0 120.000
+my_gauge{abc="baz",bar="foo"} 4 180.000
+my_gauge{abc="baz",bar="foo"} 7 240.000
+# EOF

cmd/promtool/tsdb.go

@@ -15,6 +15,7 @@ package main
 
 import (
 	"bufio"
+	"bytes"
 	"context"
 	"errors"
 	"fmt"
@@ -706,7 +707,9 @@ func analyzeCompaction(ctx context.Context, block tsdb.BlockReader, indexr tsdb.
 	return nil
 }
 
-func dumpSamples(ctx context.Context, path string, mint, maxt int64, match []string) (err error) {
+type SeriesSetFormatter func(series storage.SeriesSet) error
+
+func dumpSamples(ctx context.Context, path string, mint, maxt int64, match []string, formatter SeriesSetFormatter) (err error) {
 	db, err := tsdb.OpenDBReadOnly(path, nil)
 	if err != nil {
 		return err
@@ -736,6 +739,22 @@ func dumpSamples(ctx context.Context, path string, mint, maxt int64, match []str
 		ss = q.Select(ctx, false, nil, matcherSets[0]...)
 	}
 
+	err = formatter(ss)
+	if err != nil {
+		return err
+	}
+
+	if ws := ss.Warnings(); len(ws) > 0 {
+		return tsdb_errors.NewMulti(ws.AsErrors()...).Err()
+	}
+
+	if ss.Err() != nil {
+		return ss.Err()
+	}
+	return nil
+}
+
+func formatSeriesSet(ss storage.SeriesSet) error {
 	for ss.Next() {
 		series := ss.At()
 		lbs := series.Labels()
@@ -756,14 +775,44 @@ func dumpSamples(ctx context.Context, path string, mint, maxt int64, match []str
 			return ss.Err()
 		}
 	}
+	return nil
+}
 
-	if ws := ss.Warnings(); len(ws) > 0 {
-		return tsdb_errors.NewMulti(ws.AsErrors()...).Err()
-	}
+// CondensedString is labels.Labels.String() without spaces after the commas.
+func CondensedString(ls labels.Labels) string {
+	var b bytes.Buffer
 
-	if ss.Err() != nil {
-		return ss.Err()
+	b.WriteByte('{')
+	i := 0
+	ls.Range(func(l labels.Label) {
+		if i > 0 {
+			b.WriteByte(',')
+		}
+		b.WriteString(l.Name)
+		b.WriteByte('=')
+		b.WriteString(strconv.Quote(l.Value))
+		i++
+	})
+	b.WriteByte('}')
+	return b.String()
+}
+
+func formatSeriesSetOpenMetrics(ss storage.SeriesSet) error {
+	for ss.Next() {
+		series := ss.At()
+		lbs := series.Labels()
+		metricName := lbs.Get(labels.MetricName)
+		lbs = lbs.DropMetricName()
+		it := series.Iterator(nil)
+		for it.Next() == chunkenc.ValFloat {
+			ts, val := it.At()
+			fmt.Printf("%s%s %g %.3f\n", metricName, CondensedString(lbs), val, float64(ts)/1000)
+		}
+		if it.Err() != nil {
+			return ss.Err()
+		}
 	}
+	fmt.Println("# EOF")
 	return nil
 }
 

cmd/promtool/tsdb_test.go

@@ -22,10 +22,12 @@ import (
 	"runtime"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/require"
 
 	"github.com/prometheus/prometheus/promql"
+	"github.com/prometheus/prometheus/tsdb"
 )
 
 func TestGenerateBucket(t *testing.T) {
@@ -52,7 +54,7 @@ func TestGenerateBucket(t *testing.T) {
 }
 
 // getDumpedSamples dumps samples and returns them.
-func getDumpedSamples(t *testing.T, path string, mint, maxt int64, match []string) string {
+func getDumpedSamples(t *testing.T, path string, mint, maxt int64, match []string, formatter SeriesSetFormatter) string {
 	t.Helper()
 
 	oldStdout := os.Stdout
@@ -65,6 +67,7 @@ func getDumpedSamples(t *testing.T, path string, mint, maxt int64, match []strin
 		mint,
 		maxt,
 		match,
+		formatter,
 	)
 	require.NoError(t, err)
 
@@ -76,6 +79,14 @@ func getDumpedSamples(t *testing.T, path string, mint, maxt int64, match []strin
 	return buf.String()
 }
 
+func normalizeNewLine(b []byte) []byte {
+	if strings.Contains(runtime.GOOS, "windows") {
+		// We use "/n" while dumping on windows as well.
+		return bytes.ReplaceAll(b, []byte("\r\n"), []byte("\n"))
+	}
+	return b
+}
+
 func TestTSDBDump(t *testing.T) {
 	storage := promql.LoadedStorage(t, `
 		load 1m
@@ -136,15 +147,48 @@ func TestTSDBDump(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			dumpedMetrics := getDumpedSamples(t, storage.Dir(), tt.mint, tt.maxt, tt.match)
+			dumpedMetrics := getDumpedSamples(t, storage.Dir(), tt.mint, tt.maxt, tt.match, formatSeriesSet)
 			expectedMetrics, err := os.ReadFile(tt.expectedDump)
 			require.NoError(t, err)
-			if strings.Contains(runtime.GOOS, "windows") {
-				// We use "/n" while dumping on windows as well.
-				expectedMetrics = bytes.ReplaceAll(expectedMetrics, []byte("\r\n"), []byte("\n"))
-			}
+			expectedMetrics = normalizeNewLine(expectedMetrics)
 			// even though in case of one matcher samples are not sorted, the order in the cases above should stay the same.
 			require.Equal(t, string(expectedMetrics), dumpedMetrics)
 		})
 	}
 }
+
+func TestTSDBDumpOpenMetrics(t *testing.T) {
+	storage := promql.LoadedStorage(t, `
+		load 1m
+			my_counter{foo="bar", baz="abc"} 1 2 3 4 5
+			my_gauge{bar="foo", abc="baz"} 9 8 0 4 7
+	`)
+
+	expectedMetrics, err := os.ReadFile("testdata/dump-openmetrics-test.prom")
+	require.NoError(t, err)
+	expectedMetrics = normalizeNewLine(expectedMetrics)
+	dumpedMetrics := getDumpedSamples(t, storage.Dir(), math.MinInt64, math.MaxInt64, []string{"{__name__=~'(?s:.*)'}"}, formatSeriesSetOpenMetrics)
+	require.Equal(t, string(expectedMetrics), dumpedMetrics)
+}
+
+func TestTSDBDumpOpenMetricsRoundTrip(t *testing.T) {
+	initialMetrics, err := os.ReadFile("testdata/dump-openmetrics-roundtrip-test.prom")
+	require.NoError(t, err)
+	initialMetrics = normalizeNewLine(initialMetrics)
+
+	dbDir := t.TempDir()
+	// Import samples from OM format
+	err = backfill(5000, initialMetrics, dbDir, false, false, 2*time.Hour)
+	require.NoError(t, err)
+	db, err := tsdb.Open(dbDir, nil, nil, tsdb.DefaultOptions(), nil)
+	require.NoError(t, err)
+	t.Cleanup(func() {
+		require.NoError(t, db.Close())
+	})
+
+	// Dump the blocks into OM format
+	dumpedMetrics := getDumpedSamples(t, dbDir, math.MinInt64, math.MaxInt64, []string{"{__name__=~'(?s:.*)'}"}, formatSeriesSetOpenMetrics)
+
+	// Should get back the initial metrics.
+	require.Equal(t, string(initialMetrics), dumpedMetrics)
+}

docs/command-line/promtool.md

@@ -582,6 +582,32 @@ Dump samples from a TSDB.
 
 
 
+##### `promtool tsdb dump-openmetrics`
+
+[Experimental] Dump samples from a TSDB into OpenMetrics format. Native histograms are not dumped.
+
+
+
+###### Flags
+
+| Flag | Description | Default |
+| --- | --- | --- |
+| <code class="text-nowrap">--min-time</code> | Minimum timestamp to dump. | `-9223372036854775808` |
+| <code class="text-nowrap">--max-time</code> | Maximum timestamp to dump. | `9223372036854775807` |
+| <code class="text-nowrap">--match</code> | Series selector. Can be specified multiple times. | `{__name__=~'(?s:.*)'}` |
+
+
+
+
+###### Arguments
+
+| Argument | Description | Default |
+| --- | --- | --- |
+| db path | Database path (default is data/). | `data/` |
+
+
+
+
 ##### `promtool tsdb create-blocks-from`
 
 [Experimental] Import samples from input and produce TSDB blocks. Please refer to the storage docs for more details.