Add collectors for custom commands and /proc/diskstat. Per default add a hostname tag to all measurements

collectors/diskstatMetric.go

@@ -0,0 +1,90 @@
+package collectors
+
+import (
+	//	"errors"
+	//	"fmt"
+	lp "github.com/influxdata/line-protocol"
+	"io/ioutil"
+	"log"
+	"strconv"
+	"strings"
+	"time"
+)
+
+const DISKSTATFILE = `/proc/diskstats`
+
+type DiskstatCollector struct {
+	MetricCollector
+	matches map[int]string
+}
+
+func (m *DiskstatCollector) Init() error {
+	m.name = "DiskstatCollector"
+	m.setup()
+	// https://www.kernel.org/doc/html/latest/admin-guide/iostats.html
+	m.matches = map[int]string{
+		3:  "reads",
+		4:  "reads_merged",
+		5:  "read_sectors",
+		6:  "read_ms",
+		7:  "writes",
+		8:  "writes_merged",
+		9:  "writes_sectors",
+		10: "writes_ms",
+		11: "ioops",
+		12: "ioops_ms",
+		13: "ioops_weighted_ms",
+		14: "discards",
+		15: "discards_merged",
+		16: "discards_sectors",
+		17: "discards_ms",
+		18: "flushes",
+		19: "flushes_ms",
+	}
+	_, err := ioutil.ReadFile(string(DISKSTATFILE))
+	if err == nil {
+		m.init = true
+	}
+	return err
+}
+
+func (m *DiskstatCollector) Read(interval time.Duration, out *[]lp.MutableMetric) {
+
+	buffer, err := ioutil.ReadFile(string(DISKSTATFILE))
+
+	if err != nil {
+		log.Print(err)
+		return
+	}
+
+	ll := strings.Split(string(buffer), "\n")
+
+	for _, line := range ll {
+		if len(line) == 0 {
+			continue
+		}
+		f := strings.Fields(line)
+		if strings.Contains(f[2], "loop") {
+			continue
+		}
+		tags := map[string]string{
+			"device": f[2],
+			"type":   "node",
+		}
+		for idx, name := range m.matches {
+			x, err := strconv.ParseInt(f[idx], 0, 64)
+			if err == nil {
+				y, err := lp.New(name, tags, map[string]interface{}{"value": int(x)}, time.Now())
+				if err == nil {
+					*out = append(*out, y)
+				}
+			}
+		}
+	}
+	return
+}
+
+func (m *DiskstatCollector) Close() {
+	m.init = false
+	return
+}