Add device,fsType collection to the filesystem exporter.

Collects more information for labelling scraped filesystems with the device
and fsType. This is useful for setting alerts which should change based on
filesystem type, or for filtering out shared mounts such as with NFS volumes.

collector/filesystem.go

@@ -24,6 +24,12 @@ var (
 	ignoredMountPoints = flag.String("collector.filesystem.ignored-mount-points", "^/(sys|proc|dev)($|/)", "Regexp of mount points to ignore for filesystem collector.")
 )
 
+type filesystemDetails struct {
+	device     string
+	mountPoint string
+	fsType     string
+}
+
 type filesystemCollector struct {
 	ignoredMountPointsPattern *regexp.Regexp
 
@@ -37,7 +43,7 @@ func init() {
 // Takes a prometheus registry and returns a new Collector exposing
 // network device filesystems.
 func NewFilesystemCollector() (Collector, error) {
-	var filesystemLabelNames = []string{"filesystem"}
+	var filesystemLabelNames = []string{"device", "filesystem", "fstype"}
 
 	return &filesystemCollector{
 		ignoredMountPointsPattern: regexp.MustCompile(*ignoredMountPoints),
@@ -91,25 +97,26 @@ func NewFilesystemCollector() (Collector, error) {
 
 // Expose filesystem fullness.
 func (c *filesystemCollector) Update(ch chan<- prometheus.Metric) (err error) {
-	mps, err := mountPoints()
+	mpds, err := mountPointDetails()
 	if err != nil {
 		return err
 	}
-	for _, mp := range mps {
-		if c.ignoredMountPointsPattern.MatchString(mp) {
-			log.Debugf("Ignoring mount point: %s", mp)
+	for _, mpd := range mpds {
+		if c.ignoredMountPointsPattern.MatchString(mpd.mountPoint) {
+			log.Debugf("Ignoring mount point: %s", mpd.mountPoint)
 			continue
 		}
 		buf := new(syscall.Statfs_t)
-		err := syscall.Statfs(mp, buf)
+		err := syscall.Statfs(mpd.mountPoint, buf)
 		if err != nil {
-			return fmt.Errorf("Statfs on %s returned %s", mp, err)
+			return fmt.Errorf("Statfs on %s returned %s", mpd.mountPoint, err)
 		}
-		c.size.WithLabelValues(mp).Set(float64(buf.Blocks) * float64(buf.Bsize))
-		c.free.WithLabelValues(mp).Set(float64(buf.Bfree) * float64(buf.Bsize))
-		c.avail.WithLabelValues(mp).Set(float64(buf.Bavail) * float64(buf.Bsize))
-		c.files.WithLabelValues(mp).Set(float64(buf.Files))
-		c.filesFree.WithLabelValues(mp).Set(float64(buf.Ffree))
+
+		c.size.WithLabelValues(mpd.device, mpd.mountPoint, mpd.fsType).Set(float64(buf.Blocks) * float64(buf.Bsize))
+		c.free.WithLabelValues(mpd.device, mpd.mountPoint, mpd.fsType).Set(float64(buf.Bfree) * float64(buf.Bsize))
+		c.avail.WithLabelValues(mpd.device, mpd.mountPoint, mpd.fsType).Set(float64(buf.Bavail) * float64(buf.Bsize))
+		c.files.WithLabelValues(mpd.device, mpd.mountPoint, mpd.fsType).Set(float64(buf.Files))
+		c.filesFree.WithLabelValues(mpd.device, mpd.mountPoint, mpd.fsType).Set(float64(buf.Ffree))
 	}
 	c.size.Collect(ch)
 	c.free.Collect(ch)
@@ -119,18 +126,19 @@ func (c *filesystemCollector) Update(ch chan<- prometheus.Metric) (err error) {
 	return err
 }
 
-func mountPoints() ([]string, error) {
+func mountPointDetails() ([]filesystemDetails, error) {
 	file, err := os.Open(procMounts)
 	if err != nil {
 		return nil, err
 	}
 	defer file.Close()
 
-	mountPoints := []string{}
+	filesystems := []filesystemDetails{}
+
 	scanner := bufio.NewScanner(file)
 	for scanner.Scan() {
 		parts := strings.Fields(scanner.Text())
-		mountPoints = append(mountPoints, parts[1])
+		filesystems = append(filesystems, filesystemDetails{parts[0], parts[1], parts[2]})
 	}
-	return mountPoints, nil
+	return filesystems, nil
 }