Add Ipset input plugin (#3346)

plugins/inputs/ipset/ipset.go

@@ -0,0 +1,126 @@
+package ipset
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"os/exec"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/internal"
+	"github.com/influxdata/telegraf/plugins/inputs"
+)
+
+// Ipsets is a telegraf plugin to gather packets and bytes counters from ipset
+type Ipset struct {
+	IncludeUnmatchedSets bool
+	UseSudo              bool
+	Timeout              internal.Duration
+	lister               setLister
+}
+
+type setLister func(Timeout internal.Duration, UseSudo bool) (*bytes.Buffer, error)
+
+const measurement = "ipset"
+
+var defaultTimeout = internal.Duration{Duration: time.Second}
+
+// Description returns a short description of the plugin
+func (ipset *Ipset) Description() string {
+	return "Gather packets and bytes counters from Linux ipsets"
+}
+
+// SampleConfig returns sample configuration options.
+func (ipset *Ipset) SampleConfig() string {
+	return `
+  ## By default, we only show sets which have already matched at least 1 packet.
+  ## set include_unmatched_sets = true to gather them all.
+  include_unmatched_sets = false
+  ## Adjust your sudo settings appropriately if using this option ("sudo ipset save")
+  use_sudo = false
+  ## The default timeout of 1s for ipset execution can be overridden here:
+  # timeout = "1s"
+`
+}
+
+func (ips *Ipset) Gather(acc telegraf.Accumulator) error {
+	out, e := ips.lister(ips.Timeout, ips.UseSudo)
+	if e != nil {
+		acc.AddError(e)
+	}
+
+	scanner := bufio.NewScanner(out)
+	for scanner.Scan() {
+		line := scanner.Text()
+		// Ignore sets created without the "counters" option
+		nocomment := strings.Split(line, "\"")[0]
+		if !(strings.Contains(nocomment, "packets") &&
+			strings.Contains(nocomment, "bytes")) {
+			continue
+		}
+
+		data := strings.Fields(line)
+		if len(data) < 7 {
+			acc.AddError(fmt.Errorf("Error parsing line (expected at least 7 fields): %s", line))
+			continue
+		}
+		if data[0] == "add" && (data[4] != "0" || ips.IncludeUnmatchedSets) {
+			tags := map[string]string{
+				"set":  data[1],
+				"rule": data[2],
+			}
+			packets_total, err := strconv.ParseUint(data[4], 10, 64)
+			if err != nil {
+				acc.AddError(err)
+			}
+			bytes_total, err := strconv.ParseUint(data[6], 10, 64)
+			if err != nil {
+				acc.AddError(err)
+			}
+			fields := map[string]interface{}{
+				"packets_total": packets_total,
+				"bytes_total":   bytes_total,
+			}
+			acc.AddCounter(measurement, fields, tags)
+		}
+	}
+	return nil
+}
+
+func setList(Timeout internal.Duration, UseSudo bool) (*bytes.Buffer, error) {
+	// Is ipset installed ?
+	ipsetPath, err := exec.LookPath("ipset")
+	if err != nil {
+		return nil, err
+	}
+	var args []string
+	cmdName := ipsetPath
+	if UseSudo {
+		cmdName = "sudo"
+		args = append(args, ipsetPath)
+	}
+	args = append(args, "save")
+
+	cmd := exec.Command(cmdName, args...)
+
+	var out bytes.Buffer
+	cmd.Stdout = &out
+	err = internal.RunTimeout(cmd, Timeout.Duration)
+	if err != nil {
+		return &out, fmt.Errorf("error running ipset save: %s", err)
+	}
+
+	return &out, nil
+}
+
+func init() {
+	inputs.Add("ipset", func() telegraf.Input {
+		return &Ipset{
+			lister:  setList,
+			Timeout: defaultTimeout,
+		}
+	})
+}