Fix issues from code review, and split common code into filesystem_common.go.

collector/filesystem_common.go

@@ -0,0 +1,113 @@
+// +build !nofilesystem
+
+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
+}