Make file system metadata values strings (#36697)

To better align with ECS and better store the values in Elasticsearch.

CHANGELOG.next.asciidoc

@@ -15,6 +15,7 @@ https://github.com/elastic/beats/compare/v8.8.1\...main[Check the HEAD diff]
 
 *Filebeat*
 
+- Switch types of `log.file.device`, `log.file.inode`, `log.file.idxhi`, `log.file.idxlo` and `log.file.vol` fields to strings to better align with ECS and integrations. {pull}36697[36697]
 
 *Heartbeat*
 

libbeat/reader/readfile/fs_metafields_other.go

@@ -22,6 +22,7 @@ package readfile
 import (
 	"fmt"
 	"os"
+	"strconv"
 
 	"github.com/elastic/beats/v7/libbeat/common/file"
 	"github.com/elastic/elastic-agent-libs/mapstr"
@@ -34,11 +35,11 @@ const (
 
 func setFileSystemMetadata(fi os.FileInfo, fields mapstr.M) error {
 	osstate := file.GetOSState(fi)
-	_, err := fields.Put(deviceIDKey, osstate.Device)
+	_, err := fields.Put(deviceIDKey, strconv.FormatUint(osstate.Device, 10))
 	if err != nil {
 		return fmt.Errorf("failed to set %q: %w", deviceIDKey, err)
 	}
-	_, err = fields.Put(inodeKey, osstate.Inode)
+	_, err = fields.Put(inodeKey, osstate.InodeString())
 	if err != nil {
 		return fmt.Errorf("failed to set %q: %w", inodeKey, err)
 	}

libbeat/reader/readfile/fs_metafields_windows.go

@@ -20,6 +20,7 @@ package readfile
 import (
 	"fmt"
 	"os"
+	"strconv"
 
 	"github.com/elastic/beats/v7/libbeat/common/file"
 	"github.com/elastic/elastic-agent-libs/mapstr"
@@ -33,15 +34,15 @@ const (
 
 func setFileSystemMetadata(fi os.FileInfo, fields mapstr.M) error {
 	osstate := file.GetOSState(fi)
-	_, err := fields.Put(idxhiKey, osstate.IdxHi)
+	_, err := fields.Put(idxhiKey, strconv.FormatUint(osstate.IdxHi, 10))
 	if err != nil {
 		return fmt.Errorf("failed to set %q: %w", idxhiKey, err)
 	}
-	_, err = fields.Put(idxloKey, osstate.IdxLo)
+	_, err = fields.Put(idxloKey, strconv.FormatUint(osstate.IdxLo, 10))
 	if err != nil {
 		return fmt.Errorf("failed to set %q: %w", idxloKey, err)
 	}
-	_, err = fields.Put(volKey, osstate.Vol)
+	_, err = fields.Put(volKey, strconv.FormatUint(osstate.Vol, 10))
 	if err != nil {
 		return fmt.Errorf("failed to set %q: %w", volKey, err)
 	}

libbeat/reader/readfile/metafields_other_test.go

@@ -44,13 +44,13 @@ func checkFields(t *testing.T, expected, actual mapstr.M) {
 
 	dev, err := actual.GetValue(deviceIDKey)
 	require.NoError(t, err)
-	require.Equal(t, uint64(17), dev)
+	require.Equal(t, "17", dev)
 	err = actual.Delete(deviceIDKey)
 	require.NoError(t, err)
 
 	inode, err := actual.GetValue(inodeKey)
 	require.NoError(t, err)
-	require.Equal(t, uint64(999), inode)
+	require.Equal(t, "999", inode)
 	err = actual.Delete(inodeKey)
 	require.NoError(t, err)
 

libbeat/reader/readfile/metafields_windows_test.go

@@ -52,19 +52,19 @@ func checkFields(t *testing.T, expected, actual mapstr.M) {
 
 	idxhi, err := actual.GetValue(idxhiKey)
 	require.NoError(t, err)
-	require.Equal(t, uint64(100), idxhi)
+	require.Equal(t, "100", idxhi)
 	err = actual.Delete(idxhiKey)
 	require.NoError(t, err)
 
 	idxlo, err := actual.GetValue(idxloKey)
 	require.NoError(t, err)
-	require.Equal(t, uint64(200), idxlo)
+	require.Equal(t, "200", idxlo)
 	err = actual.Delete(idxloKey)
 	require.NoError(t, err)
 
 	vol, err := actual.GetValue(volKey)
 	require.NoError(t, err)
-	require.Equal(t, uint64(300), vol)
+	require.Equal(t, "300", vol)
 	err = actual.Delete(volKey)
 	require.NoError(t, err)