Moved system package inputs out to top level (#4406)

plugins/inputs/swap/swap.go

@@ -0,0 +1,48 @@
+package swap
+
+import (
+	"fmt"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/plugins/inputs"
+	"github.com/influxdata/telegraf/plugins/inputs/system"
+)
+
+type SwapStats struct {
+	ps system.PS
+}
+
+func (_ *SwapStats) Description() string {
+	return "Read metrics about swap memory usage"
+}
+
+func (_ *SwapStats) SampleConfig() string { return "" }
+
+func (s *SwapStats) Gather(acc telegraf.Accumulator) error {
+	swap, err := s.ps.SwapStat()
+	if err != nil {
+		return fmt.Errorf("error getting swap memory info: %s", err)
+	}
+
+	fieldsG := map[string]interface{}{
+		"total":        swap.Total,
+		"used":         swap.Used,
+		"free":         swap.Free,
+		"used_percent": swap.UsedPercent,
+	}
+	fieldsC := map[string]interface{}{
+		"in":  swap.Sin,
+		"out": swap.Sout,
+	}
+	acc.AddGauge("swap", fieldsG, nil)
+	acc.AddCounter("swap", fieldsC, nil)
+
+	return nil
+}
+
+func init() {
+	ps := system.NewSystemPS()
+	inputs.Add("swap", func() telegraf.Input {
+		return &SwapStats{ps: ps}
+	})
+}