zfs: prometheus metrics

refs #67

zfs/prometheus.go

@@ -0,0 +1,53 @@
+package zfs
+
+import "github.com/prometheus/client_golang/prometheus"
+
+var prom struct {
+	ZFSListFilesystemVersionDuration    *prometheus.HistogramVec
+	ZFSDestroyFilesystemVersionDuration *prometheus.HistogramVec
+	ZFSSnapshotDuration                 *prometheus.HistogramVec
+	ZFSBookmarkDuration                 *prometheus.HistogramVec
+}
+
+func init() {
+	prom.ZFSListFilesystemVersionDuration = prometheus.NewHistogramVec(prometheus.HistogramOpts{
+		Namespace: "zrepl",
+		Subsystem: "zfs",
+		Name:      "list_filesystem_versions_duration",
+		Help:      "Seconds it took for listing the versions of a given filesystem",
+	}, []string{"filesystem"})
+	prom.ZFSDestroyFilesystemVersionDuration = prometheus.NewHistogramVec(prometheus.HistogramOpts{
+		Namespace: "zrepl",
+		Subsystem: "zfs",
+		Name:      "destroy_filesystem_version_duration",
+		Help:      "Seconds it took to destroy a version of a given filesystem",
+	}, []string{"filesystem", "version_type"})
+	prom.ZFSSnapshotDuration = prometheus.NewHistogramVec(prometheus.HistogramOpts{
+		Namespace: "zrepl",
+		Subsystem: "zfs",
+		Name:      "snapshot_duration",
+		Help:      "Seconds it took to create a snapshot a given filesystem",
+	}, []string{"filesystem"})
+	prom.ZFSBookmarkDuration = prometheus.NewHistogramVec(prometheus.HistogramOpts{
+		Namespace: "zrepl",
+		Subsystem: "zfs",
+		Name:      "bookmark_duration",
+		Help:      "Duration it took to bookmark a given snapshot",
+	}, []string{"filesystem"})
+}
+
+func PrometheusRegister(registry prometheus.Registerer) error {
+	if err := registry.Register(prom.ZFSListFilesystemVersionDuration); err != nil {
+		return err
+	}
+	if err := registry.Register(prom.ZFSDestroyFilesystemVersionDuration); err != nil {
+		return err
+	}
+	if err := registry.Register(prom.ZFSBookmarkDuration); err != nil {
+		return err
+	}
+	if err := registry.Register(prom.ZFSSnapshotDuration); err != nil {
+		return err
+	}
+	return nil
+}