add ZFS plugin

plugins/zfs/zfs.go

@@ -0,0 +1,88 @@
+package zfs
+
+import (
+	"path/filepath"
+	"strconv"
+	"strings"
+
+	"github.com/influxdb/telegraf/plugins"
+	"github.com/shirou/gopsutil/common"
+)
+
+type Zfs struct {
+	KstatPath    string
+	KstatMetrics []string
+}
+
+var sampleConfig = `
+  # ZFS kstat path
+  # If not specified, then default is:
+  # kstatPath = "/proc/spl/kstat/zfs"
+  #
+  # By default, telegraf gather all zfs stats
+  # If not specified, then default is:
+  # kstatMetrics = ["arcstats", "zfetchstats", "vdev_cache_stats"]
+`
+
+func (z *Zfs) SampleConfig() string {
+	return sampleConfig
+}
+
+func (z *Zfs) Description() string {
+	return "Read metrics of ZFS from arcstats, zfetchstats and vdev_cache_stats"
+}
+
+func getTags(kstatPath string) map[string]string {
+	var pools string
+	poolsDirs, _ := filepath.Glob(kstatPath + "/*/io")
+	for _, poolDir := range poolsDirs {
+		poolDirSplit := strings.Split(poolDir, "/")
+		pool := poolDirSplit[len(poolDirSplit)-2]
+		if len(pools) != 0 {
+			pools += "::"
+		}
+		pools += pool
+	}
+	return map[string]string{"pools": pools}
+}
+
+func (z *Zfs) Gather(acc plugins.Accumulator) error {
+	kstatMetrics := z.KstatMetrics
+	if len(kstatMetrics) == 0 {
+		kstatMetrics = []string{"arcstats", "zfetchstats", "vdev_cache_stats"}
+	}
+
+	kstatPath := z.KstatPath
+	if len(kstatPath) == 0 {
+		kstatPath = "/proc/spl/kstat/zfs"
+	}
+
+	tags := getTags(kstatPath)
+
+	for _, metric := range kstatMetrics {
+		lines, err := common.ReadLines(kstatPath + "/" + metric)
+		if err != nil {
+			panic(err)
+		}
+		for i, line := range lines {
+			if i == 0 || i == 1 {
+				continue
+			}
+			if len(line) < 1 {
+				continue
+			}
+			rawData := strings.Split(line, " ")
+			key := metric + "_" + rawData[0]
+			rawValue := rawData[len(rawData)-1]
+			value, _ := strconv.ParseInt(rawValue, 10, 64)
+			acc.Add(key, value, tags)
+		}
+	}
+	return nil
+}
+
+func init() {
+	plugins.Add("zfs", func() plugins.Plugin {
+		return &Zfs{}
+	})
+}