collector/diskstats: Add labels and metrics from udev

collector/diskstats_linux.go

@@ -17,8 +17,14 @@
 package collector
 
 import (
+	"bufio"
 	"fmt"
+	"os"
+	"strconv"
+	"strings"
+
 	"github.com/go-kit/log"
+	"github.com/go-kit/log/level"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/procfs/blockdevice"
 )
@@ -31,23 +37,55 @@ const (
 	unixSectorSize = 512.0
 
 	diskstatsDefaultIgnoredDevices = "^(ram|loop|fd|(h|s|v|xv)d[a-z]|nvme\\d+n\\d+p)\\d+$"
+
+	// See udevadm(8).
+	udevDevicePropertyPrefix = "E:"
+
+	// Udev device properties.
+	udevDMLVLayer               = "DM_LV_LAYER"
+	udevDMLVName                = "DM_LV_NAME"
+	udevDMName                  = "DM_NAME"
+	udevDMUUID                  = "DM_UUID"
+	udevDMVGName                = "DM_VG_NAME"
+	udevIDATA                   = "ID_ATA"
+	udevIDATARotationRateRPM    = "ID_ATA_ROTATION_RATE_RPM"
+	udevIDATASATA               = "ID_ATA_SATA"
+	udevIDATASATASignalRateGen1 = "ID_ATA_SATA_SIGNAL_RATE_GEN1"
+	udevIDATASATASignalRateGen2 = "ID_ATA_SATA_SIGNAL_RATE_GEN2"
+	udevIDATAWriteCache         = "ID_ATA_WRITE_CACHE"
+	udevIDATAWriteCacheEnabled  = "ID_ATA_WRITE_CACHE_ENABLED"
+	udevIDFSType                = "ID_FS_TYPE"
+	udevIDFSUsage               = "ID_FS_USAGE"
+	udevIDFSUUID                = "ID_FS_UUID"
+	udevIDFSVersion             = "ID_FS_VERSION"
+	udevIDModel                 = "ID_MODEL"
+	udevIDPath                  = "ID_PATH"
+	udevIDRevision              = "ID_REVISION"
+	udevIDSerialShort           = "ID_SERIAL_SHORT"
+	udevIDWWN                   = "ID_WWN"
 )
 
 type typedFactorDesc struct {
 	desc      *prometheus.Desc
 	valueType prometheus.ValueType
 }
 
+type udevInfo map[string]string
+
 func (d *typedFactorDesc) mustNewConstMetric(value float64, labels ...string) prometheus.Metric {
 	return prometheus.MustNewConstMetric(d.desc, d.valueType, value, labels...)
 }
 
 type diskstatsCollector struct {
-	deviceFilter deviceFilter
-	fs           blockdevice.FS
-	infoDesc     typedFactorDesc
-	descs        []typedFactorDesc
-	logger       log.Logger
+	deviceFilter            deviceFilter
+	fs                      blockdevice.FS
+	infoDesc                typedFactorDesc
+	descs                   []typedFactorDesc
+	filesystemInfoDesc      typedFactorDesc
+	deviceMapperInfoDesc    typedFactorDesc
+	ataDescs                map[string]typedFactorDesc
+	logger                  log.Logger
+	getUdevDeviceProperties func(uint32, uint32) (udevInfo, error)
 }
 
 func init() {
@@ -68,13 +106,13 @@ func NewDiskstatsCollector(logger log.Logger) (Collector, error) {
 		return nil, fmt.Errorf("failed to parse device filter flags: %w", err)
 	}
 
-	return &diskstatsCollector{
+	collector := diskstatsCollector{
 		deviceFilter: deviceFilter,
 		fs:           fs,
 		infoDesc: typedFactorDesc{
 			desc: prometheus.NewDesc(prometheus.BuildFQName(namespace, diskSubsystem, "info"),
 				"Info of /sys/block/<block_device>.",
-				[]string{"device", "major", "minor"},
+				[]string{"device", "major", "minor", "path", "wwn", "model", "serial", "revision"},
 				nil,
 			), valueType: prometheus.GaugeValue,
 		},
@@ -181,8 +219,54 @@ func NewDiskstatsCollector(logger log.Logger) (Collector, error) {
 				), valueType: prometheus.CounterValue,
 			},
 		},
+		filesystemInfoDesc: typedFactorDesc{
+			desc: prometheus.NewDesc(prometheus.BuildFQName(namespace, diskSubsystem, "filesystem_info"),
+				"Info about disk filesystem.",
+				[]string{"device", "type", "usage", "uuid", "version"},
+				nil,
+			), valueType: prometheus.GaugeValue,
+		},
+		deviceMapperInfoDesc: typedFactorDesc{
+			desc: prometheus.NewDesc(prometheus.BuildFQName(namespace, diskSubsystem, "device_mapper_info"),
+				"Info about disk device mapper.",
+				[]string{"device", "name", "uuid", "vg_name", "lv_name", "lv_layer"},
+				nil,
+			), valueType: prometheus.GaugeValue,
+		},
+		ataDescs: map[string]typedFactorDesc{
+			udevIDATAWriteCache: {
+				desc: prometheus.NewDesc(prometheus.BuildFQName(namespace, diskSubsystem, "ata_write_cache"),
+					"ATA disk has a write cache.",
+					[]string{"device"},
+					nil,
+				), valueType: prometheus.GaugeValue,
+			},
+			udevIDATAWriteCacheEnabled: {
+				desc: prometheus.NewDesc(prometheus.BuildFQName(namespace, diskSubsystem, "ata_write_cache_enabled"),
+					"ATA disk has its write cache enabled.",
+					[]string{"device"},
+					nil,
+				), valueType: prometheus.GaugeValue,
+			},
+			udevIDATARotationRateRPM: {
+				desc: prometheus.NewDesc(prometheus.BuildFQName(namespace, diskSubsystem, "ata_rotation_rate_rpm"),
+					"ATA disk rotation rate in RPMs (0 for SSDs).",
+					[]string{"device"},
+					nil,
+				), valueType: prometheus.GaugeValue,
+			},
+		},
 		logger: logger,
-	}, nil
+	}
+
+	// Only enable getting device properties from udev if the directory is readable.
+	if stat, err := os.Stat(*udevDataPath); err != nil || !stat.IsDir() {
+		level.Error(logger).Log("msg", "Failed to open directory, disabling udev device properties", "path", *udevDataPath)
+	} else {
+		collector.getUdevDeviceProperties = getUdevDeviceProperties
+	}
+
+	return &collector, nil
 }
 
 func (c *diskstatsCollector) Update(ch chan<- prometheus.Metric) error {
@@ -196,7 +280,21 @@ func (c *diskstatsCollector) Update(ch chan<- prometheus.Metric) error {
 		if c.deviceFilter.ignored(dev) {
 			continue
 		}
-		ch <- c.infoDesc.mustNewConstMetric(1.0, dev, fmt.Sprint(stats.MajorNumber), fmt.Sprint(stats.MinorNumber))
+
+		info, err := getUdevDeviceProperties(stats.MajorNumber, stats.MinorNumber)
+		if err != nil {
+			level.Debug(c.logger).Log("msg", "Failed to parse udev info", "err", err)
+		}
+
+		ch <- c.infoDesc.mustNewConstMetric(1.0, dev,
+			fmt.Sprint(stats.MajorNumber),
+			fmt.Sprint(stats.MinorNumber),
+			info[udevIDPath],
+			info[udevIDWWN],
+			info[udevIDModel],
+			info[udevIDSerialShort],
+			info[udevIDRevision],
+		)
 
 		statCount := stats.IoStatsCount - 3 // Total diskstats record count, less MajorNumber, MinorNumber and DeviceName
 
@@ -224,6 +322,77 @@ func (c *diskstatsCollector) Update(ch chan<- prometheus.Metric) error {
 			}
 			ch <- c.descs[i].mustNewConstMetric(val, dev)
 		}
+
+		if fsType := info[udevIDFSType]; fsType != "" {
+			ch <- c.filesystemInfoDesc.mustNewConstMetric(1.0, dev,
+				fsType,
+				info[udevIDFSUsage],
+				info[udevIDFSUUID],
+				info[udevIDFSVersion],
+			)
+		}
+
+		if name := info[udevDMName]; name != "" {
+			ch <- c.deviceMapperInfoDesc.mustNewConstMetric(1.0, dev,
+				name,
+				info[udevDMUUID],
+				info[udevDMVGName],
+				info[udevDMLVName],
+				info[udevDMLVLayer],
+			)
+		}
+
+		if ata := info[udevIDATA]; ata != "" {
+			for attr, desc := range c.ataDescs {
+				str, ok := info[attr]
+				if !ok {
+					level.Debug(c.logger).Log("msg", "Udev attribute does not exist", "attribute", attr)
+					continue
+				}
+
+				if value, err := strconv.ParseFloat(str, 64); err == nil {
+					ch <- desc.mustNewConstMetric(value, dev)
+				} else {
+					level.Error(c.logger).Log("msg", "Failed to parse ATA value", "err", err)
+				}
+			}
+		}
 	}
 	return nil
 }
+
+func getUdevDeviceProperties(major, minor uint32) (udevInfo, error) {
+	filename := udevDataFilePath(fmt.Sprintf("b%d:%d", major, minor))
+
+	data, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+	defer data.Close()
+
+	info := make(udevInfo)
+
+	scanner := bufio.NewScanner(data)
+	for scanner.Scan() {
+		line := scanner.Text()
+
+		// We're only interested in device properties.
+		if !strings.HasPrefix(line, udevDevicePropertyPrefix) {
+			continue
+		}
+
+		line = strings.TrimPrefix(line, udevDevicePropertyPrefix)
+
+		/* TODO: After we drop support for Go 1.17, the condition below can be simplified to:
+
+		if name, value, found := strings.Cut(line, "="); found {
+			info[name] = value
+		}
+		*/
+		if fields := strings.SplitN(line, "=", 2); len(fields) == 2 {
+			info[fields[0]] = fields[1]
+		}
+	}
+
+	return info, nil
+}

collector/diskstats_linux_test.go

@@ -49,8 +49,32 @@ func NewTestDiskStatsCollector(logger log.Logger) (prometheus.Collector, error)
 func TestDiskStats(t *testing.T) {
 	*sysPath = "fixtures/sys"
 	*procPath = "fixtures/proc"
+	*udevDataPath = "fixtures/udev/data"
 	*diskstatsDeviceExclude = "^(ram|loop|fd|(h|s|v|xv)d[a-z]|nvme\\d+n\\d+p)\\d+$"
-	testcase := `# HELP node_disk_discard_time_seconds_total This is the total number of seconds spent by all discards.
+	testcase := `# HELP node_disk_ata_rotation_rate_rpm ATA disk rotation rate in RPMs (0 for SSDs).
+# TYPE node_disk_ata_rotation_rate_rpm gauge
+node_disk_ata_rotation_rate_rpm{device="sda"} 7200
+node_disk_ata_rotation_rate_rpm{device="sdb"} 0
+node_disk_ata_rotation_rate_rpm{device="sdc"} 0
+# HELP node_disk_ata_write_cache ATA disk has a write cache.
+# TYPE node_disk_ata_write_cache gauge
+node_disk_ata_write_cache{device="sda"} 1
+node_disk_ata_write_cache{device="sdb"} 1
+node_disk_ata_write_cache{device="sdc"} 1
+# HELP node_disk_ata_write_cache_enabled ATA disk has its write cache enabled.
+# TYPE node_disk_ata_write_cache_enabled gauge
+node_disk_ata_write_cache_enabled{device="sda"} 0
+node_disk_ata_write_cache_enabled{device="sdb"} 1
+node_disk_ata_write_cache_enabled{device="sdc"} 0
+# HELP node_disk_device_mapper_info Info about disk device mapper.
+# TYPE node_disk_device_mapper_info gauge
+node_disk_device_mapper_info{device="dm-0",lv_layer="",lv_name="",name="nvme0n1_crypt",uuid="CRYPT-LUKS2-jolaulot80fy9zsiobkxyxo7y2dqeho2-nvme0n1_crypt",vg_name=""} 1
+node_disk_device_mapper_info{device="dm-1",lv_layer="",lv_name="swap_1",name="system-swap_1",uuid="LVM-wbGqQEBL9SxrW2DLntJwgg8fAv946hw3Tvjqh0v31fWgxEtD4BoHO0lROWFUY65T",vg_name="system"} 1
+node_disk_device_mapper_info{device="dm-2",lv_layer="",lv_name="root",name="system-root",uuid="LVM-NWEDo8q5ABDyJuC3F8veKNyWfYmeIBfFMS4MF3HakzUhkk7ekDm6fJTHkl2fYHe7",vg_name="system"} 1
+node_disk_device_mapper_info{device="dm-3",lv_layer="",lv_name="var",name="system-var",uuid="LVM-hrxHo0rlZ6U95ku5841Lpd17bS1Z7V7lrtEE60DVgE6YEOCdS9gcDGyonWim4hGP",vg_name="system"} 1
+node_disk_device_mapper_info{device="dm-4",lv_layer="",lv_name="tmp",name="system-tmp",uuid="LVM-XTNGOHjPWLHcxmJmVu5cWTXEtuzqDeBkdEHAZW5q9LxWQ2d4mb5CchUQzUPJpl8H",vg_name="system"} 1
+node_disk_device_mapper_info{device="dm-5",lv_layer="",lv_name="home",name="system-home",uuid="LVM-MtoJaWTpjWRXlUnNFlpxZauTEuYlMvGFutigEzCCrfj8CNh6jCRi5LQJXZCpLjPf",vg_name="system"} 1
+# HELP node_disk_discard_time_seconds_total This is the total number of seconds spent by all discards.
 # TYPE node_disk_discard_time_seconds_total counter
 node_disk_discard_time_seconds_total{device="sdb"} 11.13
 node_disk_discard_time_seconds_total{device="sdc"} 11.13
@@ -66,6 +90,18 @@ node_disk_discards_completed_total{device="sdc"} 18851
 # TYPE node_disk_discards_merged_total counter
 node_disk_discards_merged_total{device="sdb"} 0
 node_disk_discards_merged_total{device="sdc"} 0
+# HELP node_disk_filesystem_info Info about disk filesystem.
+# TYPE node_disk_filesystem_info gauge
+node_disk_filesystem_info{device="dm-0",type="LVM2_member",usage="raid",uuid="c3C3uW-gD96-Yw69-c1CJ-5MwT-6ysM-mST0vB",version="LVM2 001"} 1
+node_disk_filesystem_info{device="dm-1",type="swap",usage="other",uuid="5272bb60-04b5-49cd-b730-be57c7604450",version="1"} 1
+node_disk_filesystem_info{device="dm-2",type="ext4",usage="filesystem",uuid="3deafd0d-faff-4695-8d15-51061ae1f51b",version="1.0"} 1
+node_disk_filesystem_info{device="dm-3",type="ext4",usage="filesystem",uuid="5c772222-f7d4-4c8e-87e8-e97df6b7a45e",version="1.0"} 1
+node_disk_filesystem_info{device="dm-4",type="ext4",usage="filesystem",uuid="a9479d44-60e1-4015-a1e5-bb065e6dd11b",version="1.0"} 1
+node_disk_filesystem_info{device="dm-5",type="ext4",usage="filesystem",uuid="b05b726a-c718-4c4d-8641-7c73a7696d83",version="1.0"} 1
+node_disk_filesystem_info{device="mmcblk0p1",type="vfat",usage="filesystem",uuid="6284-658D",version="FAT32"} 1
+node_disk_filesystem_info{device="mmcblk0p2",type="ext4",usage="filesystem",uuid="83324ce8-a6f3-4e35-ad64-dbb3d6b87a32",version="1.0"} 1
+node_disk_filesystem_info{device="sda",type="LVM2_member",usage="raid",uuid="cVVv6j-HSA2-IY33-1Jmj-dO2H-YL7w-b4Oxqw",version="LVM2 001"} 1
+node_disk_filesystem_info{device="sdc",type="LVM2_member",usage="raid",uuid="QFy9W7-Brj3-hQ6v-AF8i-3Zqg-n3Vs-kGY4vb",version="LVM2 001"} 1
 # HELP node_disk_flush_requests_time_seconds_total This is the total number of seconds spent by all flush requests.
 # TYPE node_disk_flush_requests_time_seconds_total counter
 node_disk_flush_requests_time_seconds_total{device="sdc"} 1.944
@@ -74,21 +110,21 @@ node_disk_flush_requests_time_seconds_total{device="sdc"} 1.944
 node_disk_flush_requests_total{device="sdc"} 1555
 # HELP node_disk_info Info of /sys/block/<block_device>.
 # TYPE node_disk_info gauge
-node_disk_info{device="dm-0",major="252",minor="0"} 1
-node_disk_info{device="dm-1",major="252",minor="1"} 1
-node_disk_info{device="dm-2",major="252",minor="2"} 1
-node_disk_info{device="dm-3",major="252",minor="3"} 1
-node_disk_info{device="dm-4",major="252",minor="4"} 1
-node_disk_info{device="dm-5",major="252",minor="5"} 1
-node_disk_info{device="mmcblk0",major="179",minor="0"} 1
-node_disk_info{device="mmcblk0p1",major="179",minor="1"} 1
-node_disk_info{device="mmcblk0p2",major="179",minor="2"} 1
-node_disk_info{device="nvme0n1",major="259",minor="0"} 1
-node_disk_info{device="sda",major="8",minor="0"} 1
-node_disk_info{device="sdb",major="8",minor="0"} 1
-node_disk_info{device="sdc",major="8",minor="0"} 1
-node_disk_info{device="sr0",major="11",minor="0"} 1
-node_disk_info{device="vda",major="254",minor="0"} 1
+node_disk_info{device="dm-0",major="252",minor="0",model="",path="",revision="",serial="",wwn=""} 1
+node_disk_info{device="dm-1",major="252",minor="1",model="",path="",revision="",serial="",wwn=""} 1
+node_disk_info{device="dm-2",major="252",minor="2",model="",path="",revision="",serial="",wwn=""} 1
+node_disk_info{device="dm-3",major="252",minor="3",model="",path="",revision="",serial="",wwn=""} 1
+node_disk_info{device="dm-4",major="252",minor="4",model="",path="",revision="",serial="",wwn=""} 1
+node_disk_info{device="dm-5",major="252",minor="5",model="",path="",revision="",serial="",wwn=""} 1
+node_disk_info{device="mmcblk0",major="179",minor="0",model="",path="platform-df2969f3.mmc",revision="",serial="",wwn=""} 1
+node_disk_info{device="mmcblk0p1",major="179",minor="1",model="",path="platform-df2969f3.mmc",revision="",serial="",wwn=""} 1
+node_disk_info{device="mmcblk0p2",major="179",minor="2",model="",path="platform-df2969f3.mmc",revision="",serial="",wwn=""} 1
+node_disk_info{device="nvme0n1",major="259",minor="0",model="SAMSUNG EHFTF55LURSY-000Y9",path="pci-0000:02:00.0-nvme-1",revision="4NBTUY95",serial="S252B6CU1HG3M1",wwn="eui.p3vbbiejx5aae2r3"} 1
+node_disk_info{device="sda",major="8",minor="0",model="TOSHIBA_KSDB4U86",path="pci-0000:3b:00.0-sas-phy7-lun-0",revision="0102",serial="2160A0D5FVGG",wwn="0x7c72382b8de36a64"} 1
+node_disk_info{device="sdb",major="8",minor="16",model="SuperMicro_SSD",path="pci-0000:00:1f.2-ata-1",revision="0R",serial="SMC0E1B87ABBB16BD84E",wwn="0xe1b87abbb16bd84e"} 1
+node_disk_info{device="sdc",major="8",minor="32",model="INTEL_SSDS9X9SI0",path="pci-0000:00:1f.2-ata-4",revision="0100",serial="3EWB5Y25CWQWA7EH1U",wwn="0x58907ddc573a5de"} 1
+node_disk_info{device="sr0",major="11",minor="0",model="Virtual_CDROM0",path="pci-0000:00:14.0-usb-0:1.1:1.0-scsi-0:0:0:0",revision="1.00",serial="AAAABBBBCCCC1",wwn=""} 1
+node_disk_info{device="vda",major="254",minor="0",model="",path="pci-0000:00:06.0",revision="",serial="",wwn=""} 1
 # HELP node_disk_io_now The number of I/Os currently in progress.
 # TYPE node_disk_io_now gauge
 node_disk_io_now{device="dm-0"} 0