Adding upstream version 1.34.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

plugins/inputs/fail2ban/fail2ban.go

@@ -0,0 +1,146 @@
+//go:generate ../../../tools/readme_config_includer/generator
+package fail2ban
+
+import (
+	_ "embed"
+	"errors"
+	"fmt"
+	"os/exec"
+	"strconv"
+	"strings"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/plugins/inputs"
+)
+
+//go:embed sample.conf
+var sampleConfig string
+
+var (
+	execCommand    = exec.Command // execCommand is used to mock commands in tests.
+	metricsTargets = []struct {
+		target string
+		field  string
+	}{
+		{
+			target: "Currently failed:",
+			field:  "failed",
+		},
+		{
+			target: "Currently banned:",
+			field:  "banned",
+		},
+	}
+)
+
+const cmd = "fail2ban-client"
+
+type Fail2ban struct {
+	UseSudo bool   `toml:"use_sudo"`
+	Socket  string `toml:"socket"`
+	path    string
+}
+
+func (*Fail2ban) SampleConfig() string {
+	return sampleConfig
+}
+
+func (f *Fail2ban) Init() error {
+	// Set defaults
+	if f.path == "" {
+		path, err := exec.LookPath(cmd)
+		if err != nil {
+			return fmt.Errorf("looking up %q failed: %w", cmd, err)
+		}
+		f.path = path
+	}
+
+	// Check parameters
+	if f.path == "" {
+		return fmt.Errorf("%q not found", cmd)
+	}
+
+	return nil
+}
+
+func (f *Fail2ban) Gather(acc telegraf.Accumulator) error {
+	if len(f.path) == 0 {
+		return errors.New("fail2ban-client not found: verify that fail2ban is installed and that fail2ban-client is in your PATH")
+	}
+
+	name := f.path
+	var args []string
+
+	if f.UseSudo {
+		name = "sudo"
+		args = append(args, f.path)
+	}
+
+	if f.Socket != "" {
+		args = append(args, "--socket", f.Socket)
+	}
+	args = append(args, "status")
+
+	cmd := execCommand(name, args...)
+	out, err := cmd.Output()
+	if err != nil {
+		return fmt.Errorf("failed to run command %q: %w - %s", strings.Join(cmd.Args, " "), err, string(out))
+	}
+	lines := strings.Split(string(out), "\n")
+	const targetString = "Jail list:"
+	var jails []string
+	for _, line := range lines {
+		idx := strings.LastIndex(line, targetString)
+		if idx < 0 {
+			// not target line, skip.
+			continue
+		}
+		jails = strings.Split(strings.TrimSpace(line[idx+len(targetString):]), ", ")
+		break
+	}
+
+	for _, jail := range jails {
+		// Skip over empty jails
+		if jail == "" {
+			continue
+		}
+		fields := make(map[string]interface{})
+		cmd := execCommand(name, append(args, jail)...)
+		out, err := cmd.Output()
+		if err != nil {
+			return fmt.Errorf("failed to run command %q: %w - %s", strings.Join(cmd.Args, " "), err, string(out))
+		}
+
+		lines := strings.Split(string(out), "\n")
+		for _, line := range lines {
+			key, value := extractCount(line)
+			if key != "" {
+				fields[key] = value
+			}
+		}
+		acc.AddFields("fail2ban", fields, map[string]string{"jail": jail})
+	}
+	return nil
+}
+
+func extractCount(line string) (string, int) {
+	for _, metricsTarget := range metricsTargets {
+		idx := strings.LastIndex(line, metricsTarget.target)
+		if idx < 0 {
+			continue
+		}
+		ban := strings.TrimSpace(line[idx+len(metricsTarget.target):])
+		banCount, err := strconv.Atoi(ban)
+		if err != nil {
+			return "", -1
+		}
+		return metricsTarget.field, banCount
+	}
+	return "", -1
+}
+
+func init() {
+	inputs.Add("fail2ban", func() telegraf.Input {
+		return &Fail2ban{}
+	})
+}