ethtool: Expose node_ethtool_info metric

Add a `node_ethtool_info` metric to all ethtool devices to expose driver
information with following labels:

 * bus_info
 * driver
 * expansion_rom_version
 * firmware_version
 * version

This metric is useful to monitor the firmware version to be up-to-date.

Note: The version label might be malformed due to bug #39 in ethtool:
https://github.com/safchain/ethtool/issues/39

Signed-off-by: Benjamin Drung <benjamin.drung@ionos.com>

README.md

@@ -192,7 +192,7 @@ Name     | Description | OS
 buddyinfo | Exposes statistics of memory fragments as reported by /proc/buddyinfo. | Linux
 devstat | Exposes device statistics | Dragonfly, FreeBSD
 drbd | Exposes Distributed Replicated Block Device statistics (to version 8.4) | Linux
-ethtool | Exposes network interface and network driver statistics equivalent to `ethtool -S`. | Linux
+ethtool | Exposes network interface and network driver statistics equivalent to `ethtool -S` and `ethtool -i`. | Linux
 interrupts | Exposes detailed interrupts statistics. | Linux, OpenBSD
 ksmd | Exposes kernel and system statistics from `/sys/kernel/mm/ksm`. | Linux
 logind | Exposes session counts from [logind](http://www.freedesktop.org/wiki/Software/systemd/logind/). | Linux

collector/ethtool_linux.go

@@ -45,28 +45,35 @@ var (
 	transmittedRegex       = regexp.MustCompile(`(^|_)tx(_|$)`)
 )
 
-type EthtoolStats interface {
+type Ethtool interface {
+	DriverInfo(string) (ethtool.DrvInfo, error)
 	Stats(string) (map[string]uint64, error)
 }
 
-type ethtoolStats struct {
+type ethtoolLibrary struct {
+	ethtool *ethtool.Ethtool
 }
 
-func (e *ethtoolStats) Stats(intf string) (map[string]uint64, error) {
+func (e *ethtoolLibrary) DriverInfo(intf string) (ethtool.DrvInfo, error) {
-	return ethtool.Stats(intf)
+	return e.ethtool.DriverInfo(intf)
+}
+
+func (e *ethtoolLibrary) Stats(intf string) (map[string]uint64, error) {
+	return e.ethtool.Stats(intf)
 }
 
 type ethtoolCollector struct {
 	fs                    sysfs.FS
 	entries               map[string]*prometheus.Desc
+	ethtool               Ethtool
 	ignoredDevicesPattern *regexp.Regexp
+	infoDesc              *prometheus.Desc
 	metricsPattern        *regexp.Regexp
 	logger                log.Logger
-	stats                 EthtoolStats
 }
 
 // makeEthtoolCollector is the internal constructor for EthtoolCollector.
-// This allows NewEthtoolTestCollector to override its .stats interface
+// This allows NewEthtoolTestCollector to override its .ethtool interface
 // for testing.
 func makeEthtoolCollector(logger log.Logger) (*ethtoolCollector, error) {
 	fs, err := sysfs.NewFS(*sysPath)
@@ -74,13 +81,18 @@ func makeEthtoolCollector(logger log.Logger) (*ethtoolCollector, error) {
 		return nil, fmt.Errorf("failed to open sysfs: %w", err)
 	}
 
+	e, err := ethtool.NewEthtool()
+	if err != nil {
+		return nil, fmt.Errorf("failed to initialize ethtool library: %w", err)
+	}
+
 	// Pre-populate some common ethtool metrics.
 	return &ethtoolCollector{
 		fs:                    fs,
+		ethtool:               &ethtoolLibrary{e},
 		ignoredDevicesPattern: regexp.MustCompile(*ethtoolIgnoredDevices),
 		metricsPattern:        regexp.MustCompile(*ethtoolIncludedMetrics),
 		logger:                logger,
-		stats:                 &ethtoolStats{},
 		entries: map[string]*prometheus.Desc{
 			"rx_bytes": prometheus.NewDesc(
 				prometheus.BuildFQName(namespace, "ethtool", "received_bytes_total"),
@@ -118,6 +130,11 @@ func makeEthtoolCollector(logger log.Logger) (*ethtoolCollector, error) {
 				[]string{"device"}, nil,
 			),
 		},
+		infoDesc: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, "ethtool", "info"),
+			"A metric with a constant '1' value labeled by bus_info, device, driver, expansion_rom_version, firmware_version, version.",
+			[]string{"bus_info", "device", "driver", "expansion_rom_version", "firmware_version", "version"}, nil,
+		),
 	}, nil
 }
 
@@ -175,7 +192,24 @@ func (c *ethtoolCollector) Update(ch chan<- prometheus.Metric) error {
 			continue
 		}
 
-		stats, err = c.stats.Stats(device)
+		drvInfo, err := c.ethtool.DriverInfo(device)
+
+		if err == nil {
+			ch <- prometheus.MustNewConstMetric(c.infoDesc, prometheus.GaugeValue, 1.0,
+				drvInfo.BusInfo, device, drvInfo.Driver, drvInfo.EromVersion, drvInfo.FwVersion, drvInfo.Version)
+		} else {
+			if errno, ok := err.(syscall.Errno); ok {
+				if err == unix.EOPNOTSUPP {
+					level.Debug(c.logger).Log("msg", "ethtool driver info error", "err", err, "device", device, "errno", uint(errno))
+				} else if errno != 0 {
+					level.Error(c.logger).Log("msg", "ethtool driver info error", "err", err, "device", device, "errno", uint(errno))
+				}
+			} else {
+				level.Error(c.logger).Log("msg", "ethtool driver info error", "err", err, "device", device)
+			}
+		}
+
+		stats, err = c.ethtool.Stats(device)
 
 		// If Stats() returns EOPNOTSUPP it doesn't support ethtool stats. Log that only at Debug level.
 		// Otherwise log it at Error level.

collector/ethtool_linux_test.go

@@ -25,6 +25,7 @@ import (
 
 	"github.com/go-kit/log"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/safchain/ethtool"
 	"golang.org/x/sys/unix"
 )
 
@@ -32,10 +33,49 @@ type EthtoolFixture struct {
 	fixturePath string
 }
 
+func (e *EthtoolFixture) DriverInfo(intf string) (ethtool.DrvInfo, error) {
+	res := ethtool.DrvInfo{}
+
+	fixtureFile, err := os.Open(filepath.Join(e.fixturePath, intf, "driver"))
+	if e, ok := err.(*os.PathError); ok && e.Err == syscall.ENOENT {
+		// The fixture for this interface doesn't exist. Translate that to unix.EOPNOTSUPP
+		// to replicate an interface that doesn't support ethtool driver info
+		return res, unix.EOPNOTSUPP
+	}
+	if err != nil {
+		return res, err
+	}
+	defer fixtureFile.Close()
+
+	scanner := bufio.NewScanner(fixtureFile)
+	for scanner.Scan() {
+		line := scanner.Text()
+		if strings.HasPrefix(line, "#") {
+			continue
+		}
+		line = strings.Trim(line, " ")
+		items := strings.Split(line, ": ")
+		switch items[0] {
+		case "driver":
+			res.Driver = items[1]
+		case "version":
+			res.Version = items[1]
+		case "firmware-version":
+			res.FwVersion = items[1]
+		case "bus-info":
+			res.BusInfo = items[1]
+		case "expansion-rom-version":
+			res.EromVersion = items[1]
+		}
+	}
+
+	return res, err
+}
+
 func (e *EthtoolFixture) Stats(intf string) (map[string]uint64, error) {
 	res := make(map[string]uint64)
 
-	fixtureFile, err := os.Open(filepath.Join(e.fixturePath, intf))
+	fixtureFile, err := os.Open(filepath.Join(e.fixturePath, intf, "statistics"))
 	if e, ok := err.(*os.PathError); ok && e.Err == syscall.ENOENT {
 		// The fixture for this interface doesn't exist. Translate that to unix.EOPNOTSUPP
 		// to replicate an interface that doesn't support ethtool stats
@@ -72,7 +112,7 @@ func (e *EthtoolFixture) Stats(intf string) (map[string]uint64, error) {
 
 func NewEthtoolTestCollector(logger log.Logger) (Collector, error) {
 	collector, err := makeEthtoolCollector(logger)
-	collector.stats = &EthtoolFixture{
+	collector.ethtool = &EthtoolFixture{
 		fixturePath: "fixtures/ethtool/",
 	}
 	if err != nil {
@@ -118,6 +158,9 @@ func TestBuildEthtoolFQName(t *testing.T) {
 
 func TestEthtoolCollector(t *testing.T) {
 	testcases := []string{
+		prometheus.NewDesc("node_ethtool_info",
+			"A metric with a constant '1' value labeled by bus_info, device, driver, expansion_rom_version, firmware_version, version.",
+			[]string{"bus_info", "device", "driver", "expansion_rom_version", "firmware_version", "version"}, nil).String(),
 		prometheus.NewDesc("node_ethtool_align_errors", "Network interface align_errors", []string{"device"}, nil).String(),
 		prometheus.NewDesc("node_ethtool_received_broadcast", "Network interface rx_broadcast", []string{"device"}, nil).String(),
 		prometheus.NewDesc("node_ethtool_received_errors_total", "Number of received frames with errors", []string{"device"}, nil).String(),

collector/fixtures/ethtool/eth0/driver

@@ -0,0 +1,11 @@
+# ethtool -i eth0
+driver: e1000e
+version: 5.11.0-22-generic
+firmware-version: 0.5-4
+expansion-rom-version: 
+bus-info: 0000:00:1f.6
+supports-statistics: yes
+supports-test: yes
+supports-eeprom-access: yes
+supports-register-dump: yes
+supports-priv-flags: yes