From b22d2e973976048c9a7161a2b0930382f7d89f2c Mon Sep 17 00:00:00 2001
From: William Rouesnel <William.Rouesnel@netregistry.com.au>
Date: Fri, 3 Jul 2015 09:20:49 +1000
Subject: [PATCH] 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 | 40 ++++++++++++++++++++++++----------------
 1 file changed, 24 insertions(+), 16 deletions(-)

diff --git a/collector/filesystem.go b/collector/filesystem.go
index d6b635b2..449db69d 100644
--- a/collector/filesystem.go
+++ b/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
 }