Merge branch 'master' into coolingDevice

4 files changed, 69 insertions, 13 deletions

diff --git a/collector/filesystem_linux_test.go b/collector/filesystem_linux_test.go
index 267ad06..6271c19 100644
--- a/collector/filesystem_linux_test.go
+++ b/collector/filesystem_linux_test.go
@@ -120,6 +120,7 @@ func TestPathRootfs(t *testing.T) {
 
         expected := map[string]string{
                 // should modify these mountpoints (removes /host, see fixture proc file)
+                "/":              "",
                 "/media/volume1": "",
                 "/media/volume2": "",
                 // should not modify these mountpoints
diff --git a/collector/fixtures_bindmount/proc/mounts b/collector/fixtures_bindmount/proc/mounts
index 2ef6401..32f9567 100644
--- a/collector/fixtures_bindmount/proc/mounts
+++ b/collector/fixtures_bindmount/proc/mounts
@@ -1,3 +1,4 @@
+/dev/nvme1n0 /host ext4 rw,seclabel,relatime,data=ordered 0 0
 /dev/nvme1n1 /host/media/volume1 ext4 rw,seclabel,relatime,data=ordered 0 0
 /dev/nvme1n2 /host/media/volume2 ext4 rw,seclabel,relatime,data=ordered 0 0
 tmpfs /dev/shm tmpfs rw,nosuid,nodev 0 0
diff --git a/collector/paths.go b/collector/paths.go
index 6150600..5f5a7b4 100644
--- a/collector/paths.go
+++ b/collector/paths.go
@@ -44,5 +44,9 @@ func rootfsStripPrefix(path string) string {
         if *rootfsPath == "/" {
                 return path
         }
-        return strings.TrimPrefix(path, *rootfsPath)
+        stripped := strings.TrimPrefix(path, *rootfsPath)
+        if stripped == "" {
+                return "/"
+        }
+        return stripped
 }
diff --git a/collector/systemd_linux.go b/collector/systemd_linux.go
index 4b9db10..eb1fa78 100644
--- a/collector/systemd_linux.go
+++ b/collector/systemd_linux.go
@@ -19,6 +19,7 @@ import (
         "fmt"
         "math"
         "regexp"
+        "strconv"
         "strings"
         "sync"
         "time"
@@ -29,6 +30,13 @@ import (
         kingpin "gopkg.in/alecthomas/kingpin.v2"
 )
 
+const (
+        // minSystemdVersionSystemState is the minimum SystemD version for availability of
+        // the 'SystemState' manager property and the timer property 'LastTriggerUSec'
+        // https://github.com/prometheus/node_exporter/issues/291
+        minSystemdVersionSystemState = 212
+)
+
 var (
         unitWhitelist          = kingpin.Flag("collector.systemd.unit-whitelist", "Regexp of systemd units to whitelist. Units must both match whitelist and not match blacklist to be included.").Default(".+").String()
         unitBlacklist          = kingpin.Flag("collector.systemd.unit-blacklist", "Regexp of systemd units to blacklist. Units must both match whitelist and not match blacklist to be included.").Default(".+\\.(automount|device|mount|scope|slice)").String()
@@ -50,6 +58,8 @@ type systemdCollector struct {
         socketAcceptedConnectionsDesc *prometheus.Desc
         socketCurrentConnectionsDesc  *prometheus.Desc
         socketRefusedConnectionsDesc  *prometheus.Desc
+        systemdVersionDesc            *prometheus.Desc
+        systemdVersion                int
         unitWhitelistPattern          *regexp.Regexp
         unitBlacklistPattern          *regexp.Regexp
 }
@@ -103,9 +113,18 @@ func NewSystemdCollector() (Collector, error) {
         socketRefusedConnectionsDesc := prometheus.NewDesc(
                 prometheus.BuildFQName(namespace, subsystem, "socket_refused_connections_total"),
                 "Total number of refused socket connections", []string{"name"}, nil)
+        systemdVersionDesc := prometheus.NewDesc(
+                prometheus.BuildFQName(namespace, subsystem, "version"),
+                "Detected systemd version", []string{}, nil)
         unitWhitelistPattern := regexp.MustCompile(fmt.Sprintf("^(?:%s)$", *unitWhitelist))
         unitBlacklistPattern := regexp.MustCompile(fmt.Sprintf("^(?:%s)$", *unitBlacklist))
 
+        systemdVersion := getSystemdVersion()
+        if systemdVersion < minSystemdVersionSystemState {
+                log.Warnf("Detected systemd version %v is lower than minimum %v", systemdVersion, minSystemdVersionSystemState)
+                log.Warn("Some systemd state and timer metrics will not be available")
+        }
+
         return &systemdCollector{
                 unitDesc:                      unitDesc,
                 unitStartTimeDesc:             unitStartTimeDesc,
@@ -118,6 +137,8 @@ func NewSystemdCollector() (Collector, error) {
                 socketAcceptedConnectionsDesc: socketAcceptedConnectionsDesc,
                 socketCurrentConnectionsDesc:  socketCurrentConnectionsDesc,
                 socketRefusedConnectionsDesc:  socketRefusedConnectionsDesc,
+                systemdVersionDesc:            systemdVersionDesc,
+                systemdVersion:                systemdVersion,
                 unitWhitelistPattern:          unitWhitelistPattern,
                 unitBlacklistPattern:          unitBlacklistPattern,
         }, nil
@@ -127,7 +148,7 @@ func NewSystemdCollector() (Collector, error) {
 // to reduce wait time for responses.
 func (c *systemdCollector) Update(ch chan<- prometheus.Metric) error {
         begin := time.Now()
-        conn, err := c.newDbus()
+        conn, err := newSystemdDbusConn()
         if err != nil {
                 return fmt.Errorf("couldn't get dbus connection: %s", err)
         }
@@ -179,13 +200,15 @@ func (c *systemdCollector) Update(ch chan<- prometheus.Metric) error {
                 }()
         }
 
-        wg.Add(1)
-        go func() {
-                defer wg.Done()
-                begin = time.Now()
-                c.collectTimers(conn, ch, units)
-                log.Debugf("systemd collectTimers took %f", time.Since(begin).Seconds())
-        }()
+        if c.systemdVersion >= minSystemdVersionSystemState {
+                wg.Add(1)
+                go func() {
+                        defer wg.Done()
+                        begin = time.Now()
+                        c.collectTimers(conn, ch, units)
+                        log.Debugf("systemd collectTimers took %f", time.Since(begin).Seconds())
+                }()
+        }
 
         wg.Add(1)
         go func() {
@@ -195,9 +218,15 @@ func (c *systemdCollector) Update(ch chan<- prometheus.Metric) error {
                 log.Debugf("systemd collectSockets took %f", time.Since(begin).Seconds())
         }()
 
-        begin = time.Now()
-        err = c.collectSystemState(conn, ch)
-        log.Debugf("systemd collectSystemState took %f", time.Since(begin).Seconds())
+        if c.systemdVersion >= minSystemdVersionSystemState {
+                begin = time.Now()
+                err = c.collectSystemState(conn, ch)
+                log.Debugf("systemd collectSystemState took %f", time.Since(begin).Seconds())
+        }
+
+        ch <- prometheus.MustNewConstMetric(
+                c.systemdVersionDesc, prometheus.GaugeValue, float64(c.systemdVersion))
+
         return err
 }
 
@@ -369,7 +398,7 @@ func (c *systemdCollector) collectSystemState(conn *dbus.Conn, ch chan<- prometh
         return nil
 }
 
-func (c *systemdCollector) newDbus() (*dbus.Conn, error) {
+func newSystemdDbusConn() (*dbus.Conn, error) {
         if *systemdPrivate {
                 return dbus.NewSystemdConnection()
         }
@@ -424,3 +453,24 @@ func filterUnits(units []unit, whitelistPattern, blacklistPattern *regexp.Regexp
 
         return filtered
 }
+
+func getSystemdVersion() int {
+        conn, err := newSystemdDbusConn()
+        if err != nil {
+                log.Warnf("Unable to get systemd dbus connection, defaulting systemd version to 0: %s", err)
+                return 0
+        }
+        defer conn.Close()
+        version, err := conn.GetManagerProperty("Version")
+        if err != nil {
+                log.Warn("Unable to get systemd version property, defaulting to 0")
+                return 0
+        }
+        version = strings.Replace(version, "\"", "", 2)
+        v, err := strconv.Atoi(version)
+        if err != nil {
+                log.Warnf("Got invalid systemd version: %v", version)
+                return 0
+        }
+        return v
+}