Merge pull request prometheus#117 from TheTincho/forget-old-filesystems

Revamp the filesystem collector to use throw-away ConstMetrics.

collector/filesystem_common.go

@@ -0,0 +1,114 @@
+// +build !nofilesystem
+// +build linux freebsd
+
+package collector
+
+import (
+	"flag"
+	"regexp"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+// Arch-dependent implementation must define:
+// * defIgnoredMountPoints
+// * filesystemLabelNames
+// * filesystemCollector.GetStats
+
+var (
+	ignoredMountPoints = flag.String(
+		"collector.filesystem.ignored-mount-points",
+		defIgnoredMountPoints,
+		"Regexp of mount points to ignore for filesystem collector.")
+)
+
+type filesystemCollector struct {
+	ignoredMountPointsPattern *regexp.Regexp
+	sizeDesc, freeDesc, availDesc,
+	filesDesc, filesFreeDesc *prometheus.Desc
+}
+
+type filesystemStats struct {
+	labelValues                         []string
+	size, free, avail, files, filesFree float64
+}
+
+func init() {
+	Factories["filesystem"] = NewFilesystemCollector
+}
+
+// Takes a prometheus registry and returns a new Collector exposing
+// Filesystems stats.
+func NewFilesystemCollector() (Collector, error) {
+	subsystem := "filesystem"
+	pattern := regexp.MustCompile(*ignoredMountPoints)
+
+	sizeDesc := prometheus.NewDesc(
+		prometheus.BuildFQName(Namespace, subsystem, "size"),
+		"Filesystem size in bytes.",
+		filesystemLabelNames, nil,
+	)
+
+	freeDesc := prometheus.NewDesc(
+		prometheus.BuildFQName(Namespace, subsystem, "free"),
+		"Filesystem free space in bytes.",
+		filesystemLabelNames, nil,
+	)
+
+	availDesc := prometheus.NewDesc(
+		prometheus.BuildFQName(Namespace, subsystem, "avail"),
+		"Filesystem space available to non-root users in bytes.",
+		filesystemLabelNames, nil,
+	)
+
+	filesDesc := prometheus.NewDesc(
+		prometheus.BuildFQName(Namespace, subsystem, "files"),
+		"Filesystem total file nodes.",
+		filesystemLabelNames, nil,
+	)
+
+	filesFreeDesc := prometheus.NewDesc(
+		prometheus.BuildFQName(Namespace, subsystem, "files_free"),
+		"Filesystem total free file nodes.",
+		filesystemLabelNames, nil,
+	)
+
+	return &filesystemCollector{
+		ignoredMountPointsPattern: pattern,
+		sizeDesc:                  sizeDesc,
+		freeDesc:                  freeDesc,
+		availDesc:                 availDesc,
+		filesDesc:                 filesDesc,
+		filesFreeDesc:             filesFreeDesc,
+	}, nil
+}
+
+func (c *filesystemCollector) Update(ch chan<- prometheus.Metric) (err error) {
+	stats, err := c.GetStats()
+	if err != nil {
+		return err
+	}
+	for _, s := range stats {
+		ch <- prometheus.MustNewConstMetric(
+			c.sizeDesc, prometheus.GaugeValue,
+			s.size, s.labelValues...,
+		)
+		ch <- prometheus.MustNewConstMetric(
+			c.freeDesc, prometheus.GaugeValue,
+			s.free, s.labelValues...,
+		)
+		ch <- prometheus.MustNewConstMetric(
+			c.availDesc, prometheus.GaugeValue,
+			s.avail, s.labelValues...,
+		)
+		ch <- prometheus.MustNewConstMetric(
+			c.filesDesc, prometheus.GaugeValue,
+			s.files, s.labelValues...,
+		)
+		ch <- prometheus.MustNewConstMetric(
+			c.filesFreeDesc, prometheus.GaugeValue,
+			s.filesFree, s.labelValues...,
+		)
+	}
+	return nil
+}

collector/filesystem_freebsd.go

@@ -4,11 +4,9 @@ package collector
 
 import (
 	"errors"
-	"flag"
 	"regexp"
 	"unsafe"
 
-	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/log"
 )
 
@@ -21,104 +19,38 @@ import (
 import "C"
 
 const (
-	filesystemSubsystem = "filesystem"
+	defIgnoredMountPoints = "^/(dev)($|/)"
 )
 
 var (
-	ignoredMountPoints = flag.String("collector.filesystem.ignored-mount-points", "^/(dev)($|/)", "Regexp of mount points to ignore for filesystem collector.")
+	filesystemLabelNames = []string{"filesystem"}
 )
 
-type filesystemCollector struct {
-	ignoredMountPointsPattern *regexp.Regexp
-
-	size, free, avail, files, filesFree *prometheus.GaugeVec
-}
-
-func init() {
-	Factories["filesystem"] = NewFilesystemCollector
-}
-
-// Takes a prometheus registry and returns a new Collector exposing
-// Filesystems stats.
-func NewFilesystemCollector() (Collector, error) {
-	var filesystemLabelNames = []string{"filesystem"}
-
-	return &filesystemCollector{
-		ignoredMountPointsPattern: regexp.MustCompile(*ignoredMountPoints),
-		size: prometheus.NewGaugeVec(
-			prometheus.GaugeOpts{
-				Namespace: Namespace,
-				Subsystem: filesystemSubsystem,
-				Name:      "size_bytes",
-				Help:      "Filesystem size in bytes.",
-			},
-			filesystemLabelNames,
-		),
-		free: prometheus.NewGaugeVec(
-			prometheus.GaugeOpts{
-				Namespace: Namespace,
-				Subsystem: filesystemSubsystem,
-				Name:      "free_bytes",
-				Help:      "Filesystem free space in bytes.",
-			},
-			filesystemLabelNames,
-		),
-		avail: prometheus.NewGaugeVec(
-			prometheus.GaugeOpts{
-				Namespace: Namespace,
-				Subsystem: filesystemSubsystem,
-				Name:      "avail_bytes",
-				Help:      "Filesystem space available to non-root users in bytes.",
-			},
-			filesystemLabelNames,
-		),
-		files: prometheus.NewGaugeVec(
-			prometheus.GaugeOpts{
-				Namespace: Namespace,
-				Subsystem: filesystemSubsystem,
-				Name:      "file_nodes",
-				Help:      "Filesystem total file nodes.",
-			},
-			filesystemLabelNames,
-		),
-		filesFree: prometheus.NewGaugeVec(
-			prometheus.GaugeOpts{
-				Namespace: Namespace,
-				Subsystem: filesystemSubsystem,
-				Name:      "file_free_nodes",
-				Help:      "Filesystem total free file nodes.",
-			},
-			filesystemLabelNames,
-		),
-	}, nil
-}
-
 // Expose filesystem fullness.
-func (c *filesystemCollector) Update(ch chan<- prometheus.Metric) (err error) {
+func (c *filesystemCollector) GetStats() (stats []filesystemStats, err error) {
 	var mntbuf *C.struct_statfs
 	count := C.getmntinfo(&mntbuf, C.MNT_NOWAIT)
 	if count == 0 {
-		return errors.New("getmntinfo() failed")
+		return nil, errors.New("getmntinfo() failed")
 	}
 
 	mnt := (*[1 << 30]C.struct_statfs)(unsafe.Pointer(mntbuf))
+	stats = []filesystemStats{}
 	for i := 0; i < int(count); i++ {
 		name := C.GoString(&mnt[i].f_mntonname[0])
 		if c.ignoredMountPointsPattern.MatchString(name) {
 			log.Debugf("Ignoring mount point: %s", name)
 			continue
 		}
-		c.size.WithLabelValues(name).Set(float64(mnt[i].f_blocks) * float64(mnt[i].f_bsize))
-		c.free.WithLabelValues(name).Set(float64(mnt[i].f_bfree) * float64(mnt[i].f_bsize))
-		c.avail.WithLabelValues(name).Set(float64(mnt[i].f_bavail) * float64(mnt[i].f_bsize))
-		c.files.WithLabelValues(name).Set(float64(mnt[i].f_files))
-		c.filesFree.WithLabelValues(name).Set(float64(mnt[i].f_ffree))
+		labelValues := []string{name}
+		stats = append(stats, filesystemStats{
+			labelValues: labelValues,
+			size:        float64(mnt[i].f_blocks) * float64(mnt[i].f_bsize),
+			free:        float64(mnt[i].f_bfree) * float64(mnt[i].f_bsize),
+			avail:       float64(mnt[i].f_bavail) * float64(mnt[i].f_bsize),
+			files:       float64(mnt[i].f_files),
+			filesFree:   float64(mnt[i].f_ffree),
+		})
 	}
-
-	c.size.Collect(ch)
-	c.free.Collect(ch)
-	c.avail.Collect(ch)
-	c.files.Collect(ch)
-	c.filesFree.Collect(ch)
-	return err
+	return stats, nil
 }

collector/filesystem_linux.go

@@ -4,24 +4,21 @@ package collector
 
 import (
 	"bufio"
-	"flag"
 	"fmt"
 	"os"
-	"regexp"
 	"strings"
 	"syscall"
 
-	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/log"
 )
 
 const (
-	procMounts          = "/proc/mounts"
-	filesystemSubsystem = "filesystem"
+	defIgnoredMountPoints = "^/(sys|proc|dev)($|/)"
+	procMounts            = "/proc/mounts"
 )
 
 var (
-	ignoredMountPoints = flag.String("collector.filesystem.ignored-mount-points", "^/(sys|proc|dev)($|/)", "Regexp of mount points to ignore for filesystem collector.")
+	filesystemLabelNames = []string{"device", "mountpoint", "fstype"}
 )
 
 type filesystemDetails struct {
@@ -30,77 +27,13 @@ type filesystemDetails struct {
 	fsType     string
 }
 
-type filesystemCollector struct {
-	ignoredMountPointsPattern *regexp.Regexp
-
-	size, free, avail, files, filesFree *prometheus.GaugeVec
-}
-
-func init() {
-	Factories["filesystem"] = NewFilesystemCollector
-}
-
-// Takes a prometheus registry and returns a new Collector exposing
-// network device filesystems.
-func NewFilesystemCollector() (Collector, error) {
-	var filesystemLabelNames = []string{"device", "mountpoint", "fstype"}
-
-	return &filesystemCollector{
-		ignoredMountPointsPattern: regexp.MustCompile(*ignoredMountPoints),
-		size: prometheus.NewGaugeVec(
-			prometheus.GaugeOpts{
-				Namespace: Namespace,
-				Subsystem: filesystemSubsystem,
-				Name:      "size",
-				Help:      "Filesystem size in bytes.",
-			},
-			filesystemLabelNames,
-		),
-		free: prometheus.NewGaugeVec(
-			prometheus.GaugeOpts{
-				Namespace: Namespace,
-				Subsystem: filesystemSubsystem,
-				Name:      "free",
-				Help:      "Filesystem free space in bytes.",
-			},
-			filesystemLabelNames,
-		),
-		avail: prometheus.NewGaugeVec(
-			prometheus.GaugeOpts{
-				Namespace: Namespace,
-				Subsystem: filesystemSubsystem,
-				Name:      "avail",
-				Help:      "Filesystem space available to non-root users in bytes.",
-			},
-			filesystemLabelNames,
-		),
-		files: prometheus.NewGaugeVec(
-			prometheus.GaugeOpts{
-				Namespace: Namespace,
-				Subsystem: filesystemSubsystem,
-				Name:      "files",
-				Help:      "Filesystem total file nodes.",
-			},
-			filesystemLabelNames,
-		),
-		filesFree: prometheus.NewGaugeVec(
-			prometheus.GaugeOpts{
-				Namespace: Namespace,
-				Subsystem: filesystemSubsystem,
-				Name:      "files_free",
-				Help:      "Filesystem total free file nodes.",
-			},
-			filesystemLabelNames,
-		),
-	}, nil
-}
-
 // Expose filesystem fullness.
-func (c *filesystemCollector) Update(ch chan<- prometheus.Metric) (err error) {
+func (c *filesystemCollector) GetStats() (stats []filesystemStats, err error) {
 	mpds, err := mountPointDetails()
 	if err != nil {
-		return err
+		return nil, err
 	}
+	stats = []filesystemStats{}
 	for _, mpd := range mpds {
 		if c.ignoredMountPointsPattern.MatchString(mpd.mountPoint) {
 			log.Debugf("Ignoring mount point: %s", mpd.mountPoint)
@@ -109,21 +42,21 @@ func (c *filesystemCollector) Update(ch chan<- prometheus.Metric) (err error) {
 		buf := new(syscall.Statfs_t)
 		err := syscall.Statfs(mpd.mountPoint, buf)
 		if err != nil {
-			return fmt.Errorf("Statfs on %s returned %s", mpd.mountPoint, err)
+			return nil, fmt.Errorf("Statfs on %s returned %s",
+				mpd.mountPoint, err)
 		}
 
-		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))
+		labelValues := []string{mpd.device, mpd.mountPoint, mpd.fsType}
+		stats = append(stats, filesystemStats{
+			labelValues: labelValues,
+			size:        float64(buf.Blocks) * float64(buf.Bsize),
+			free:        float64(buf.Bfree) * float64(buf.Bsize),
+			avail:       float64(buf.Bavail) * float64(buf.Bsize),
+			files:       float64(buf.Files),
+			filesFree:   float64(buf.Ffree),
+		})
 	}
-	c.size.Collect(ch)
-	c.free.Collect(ch)
-	c.avail.Collect(ch)
-	c.files.Collect(ch)
-	c.filesFree.Collect(ch)
-	return err
+	return stats, nil
 }
 
 func mountPointDetails() ([]filesystemDetails, error) {