From 3f0814f13baa4ca39f6e5f1e68a83b32ea96d587 Mon Sep 17 00:00:00 2001
From: Brian Brazil <brian.brazil@boxever.com>
Date: Thu, 5 Jun 2014 20:44:44 +0100
Subject: [PATCH] Add filesystem collector module, to report space used etc.

---
 collector/filesystem.go | 123 ++++++++++++++++++++++++++++++++++++++++
 node_exporter.go        |   2 +-
 2 files changed, 124 insertions(+), 1 deletion(-)
 create mode 100644 collector/filesystem.go

diff --git a/collector/filesystem.go b/collector/filesystem.go
new file mode 100644
index 00000000..08e729ae
--- /dev/null
+++ b/collector/filesystem.go
@@ -0,0 +1,123 @@
+// +build !nofilesystem
+
+package collector
+
+import (
+	"bufio"
+	"flag"
+	"fmt"
+	"os"
+	"regexp"
+	"strings"
+	"syscall"
+
+        "github.com/golang/glog"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+const (
+	procMounts = "/proc/mounts"
+)
+
+var (
+	fsSizeMetric      = prometheus.NewGauge()
+	fsFreeMetric      = prometheus.NewGauge()
+	fsAvailMetric     = prometheus.NewGauge()
+	fsFilesMetric     = prometheus.NewGauge()
+	fsFilesFreeMetric = prometheus.NewGauge()
+
+	ignoredMountPoints = flag.String("filesystemIgnoredMountPoints", "^/(sys|proc|dev)($|/)", "Regexp of mount points to ignore for filesystem collector.")
+)
+
+type filesystemCollector struct {
+	registry                  prometheus.Registry
+	config                    Config
+	ignoredMountPointsPattern *regexp.Regexp
+}
+
+func init() {
+	Factories["filesystem"] = NewFilesystemCollector
+}
+
+// Takes a config struct and prometheus registry and returns a new Collector exposing
+// network device filesystems.
+func NewFilesystemCollector(config Config, registry prometheus.Registry) (Collector, error) {
+	c := filesystemCollector{
+		config:                    config,
+		registry:                  registry,
+		ignoredMountPointsPattern: regexp.MustCompile(*ignoredMountPoints),
+	}
+	registry.Register(
+		"node_filesystem_size",
+		"Filesystem size in bytes.",
+		prometheus.NilLabels,
+		fsSizeMetric,
+	)
+	registry.Register(
+		"node_filesystem_free",
+		"Filesystem free space in bytes.",
+		prometheus.NilLabels,
+		fsFreeMetric,
+	)
+	registry.Register(
+		"node_filesystem_avail",
+		"Filesystem space available to non-root users in bytes.",
+		prometheus.NilLabels,
+		fsAvailMetric,
+	)
+	registry.Register(
+		"node_filesystem_files",
+		"Filesystem total file nodes.",
+		prometheus.NilLabels,
+		fsFilesMetric,
+	)
+	registry.Register(
+		"node_filesystem_files_free",
+		"Filesystem total free file nodes.",
+		prometheus.NilLabels,
+		fsFilesFreeMetric,
+	)
+	return &c, nil
+}
+
+// Expose filesystem fullness.
+func (c *filesystemCollector) Update() (updates int, err error) {
+	mps, err := mountPoints()
+	if err != nil {
+		return updates, err
+	}
+	for _, mp := range mps {
+		if c.ignoredMountPointsPattern.MatchString(mp) {
+			glog.V(1).Infof("Ignoring mount point: %s", mp)
+			continue
+		}
+		buf := new(syscall.Statfs_t)
+		err := syscall.Statfs(mp, buf)
+		if err != nil {
+			return updates, fmt.Errorf("Statfs on %s returned %s", mp, err)
+		}
+		fsSizeMetric.Set(map[string]string{"filesystem": mp}, float64(buf.Blocks)*float64(buf.Bsize))
+		fsFreeMetric.Set(map[string]string{"filesystem": mp}, float64(buf.Bfree)*float64(buf.Bsize))
+		fsAvailMetric.Set(map[string]string{"filesystem": mp}, float64(buf.Bavail)*float64(buf.Bsize))
+		fsFilesMetric.Set(map[string]string{"filesystem": mp}, float64(buf.Files))
+		fsFilesFreeMetric.Set(map[string]string{"filesystem": mp}, float64(buf.Ffree))
+		updates++
+	}
+	return updates, err
+}
+
+func mountPoints() ([]string, error) {
+	file, err := os.Open(procMounts)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	mountPoints := []string{}
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		parts := strings.Fields(scanner.Text())
+		mountPoints = append(mountPoints, parts[1])
+	}
+	return mountPoints, nil
+}
diff --git a/node_exporter.go b/node_exporter.go
index 357927e8..4101aeb3 100644
--- a/node_exporter.go
+++ b/node_exporter.go
@@ -25,7 +25,7 @@ var (
 	configFile        = flag.String("config", "node_exporter.conf", "config file.")
 	memProfile        = flag.String("memprofile", "", "write memory profile to this file")
 	listeningAddress  = flag.String("listen", ":8080", "address to listen on")
-	enabledCollectors = flag.String("enabledCollectors", "attributes,diskstats,loadavg,meminfo,netdev", "comma-seperated list of collectors to use")
+	enabledCollectors = flag.String("enabledCollectors", "attributes,diskstats,filesystem,loadavg,meminfo,netdev", "comma-seperated list of collectors to use")
 	printCollectors   = flag.Bool("printCollectors", false, "If true, print available collectors and exit")
 	interval          = flag.Duration("interval", 60*time.Second, "refresh interval")
 	scrapeDurations   = prometheus.NewDefaultHistogram()