Add opensmtpd input plugin (#3449)

README.md

@@ -176,6 +176,7 @@ configuration options.
 * [nstat](./plugins/inputs/nstat)
 * [ntpq](./plugins/inputs/ntpq)
 * [openldap](./plugins/inputs/openldap)
+* [opensmtpd](./plugins/inputs/opensmtpd)
 * [phpfpm](./plugins/inputs/phpfpm)
 * [phusion passenger](./plugins/inputs/passenger)
 * [ping](./plugins/inputs/ping)

etc/telegraf.conf

@@ -1876,6 +1876,18 @@
 #   bind_password = ""
 
 
+# # A plugin to collect stats from OpenSMTPd
+# [[inputs.opensmtpd]]
+#   ## If running as a restricted user you can prepend sudo for additional access:
+#   #use_sudo = false
+#
+#   ## The default location of the smtpctl binary can be overridden with:
+#   #binary = "/usr/sbin/smtpctl"
+#
+#   ## The default timeout of 1s can be overriden with:
+#   #timeout = "1s"
+
+
 # # Read metrics of passenger using passenger-status
 # [[inputs.passenger]]
 #   ## Path of passenger-status.

plugins/inputs/all/all.go

@@ -60,6 +60,7 @@ import (
 	_ "github.com/influxdata/telegraf/plugins/inputs/nstat"
 	_ "github.com/influxdata/telegraf/plugins/inputs/ntpq"
 	_ "github.com/influxdata/telegraf/plugins/inputs/openldap"
+	_ "github.com/influxdata/telegraf/plugins/inputs/opensmtpd"
 	_ "github.com/influxdata/telegraf/plugins/inputs/passenger"
 	_ "github.com/influxdata/telegraf/plugins/inputs/phpfpm"
 	_ "github.com/influxdata/telegraf/plugins/inputs/ping"

plugins/inputs/opensmtpd/README.md

@@ -0,0 +1,102 @@
+# OpenSMTPD Input Plugin
+
+This plugin gathers stats from [OpenSMTPD - a FREE implementation of the server-side SMTP protocol](https://www.opensmtpd.org/)
+
+### Configuration:
+
+```toml
+ # A plugin to collect stats from OpenSMTPD - a FREE implementation of the server-side SMTP protocol
+ [[inputs.smtpctl]]
+   ## If running as a restricted user you can prepend sudo for additional access:
+   #use_sudo = false
+
+   ## The default location of the smtpctl binary can be overridden with:
+   binary = "/usr/sbin/smtpctl"
+
+   # The default timeout of 1s can be overriden with:
+   #timeout = "1s"
+```
+
+### Measurements & Fields:
+
+This is the full list of stats provided by smtpctl and potentially collected by telegram
+depending of your smtpctl configuration.
+
+- smtpctl
+    bounce_envelope
+    bounce_message
+    bounce_session
+    control_session
+    mda_envelope
+    mda_pending
+    mda_running
+    mda_user
+    mta_connector
+    mta_domain
+    mta_envelope
+    mta_host
+    mta_relay
+    mta_route
+    mta_session
+    mta_source
+    mta_task
+    mta_task_running
+    queue_bounce
+    queue_evpcache_load_hit
+    queue_evpcache_size
+    queue_evpcache_update_hit
+    scheduler_delivery_ok
+    scheduler_delivery_permfail
+    scheduler_delivery_tempfail
+    scheduler_envelope
+    scheduler_envelope_expired
+    scheduler_envelope_incoming
+    scheduler_envelope_inflight
+    scheduler_ramqueue_envelope
+    scheduler_ramqueue_message
+    scheduler_ramqueue_update
+    smtp_session
+    smtp_session_inet4
+    smtp_session_local
+    uptime
+
+### Permissions:
+
+It's important to note that this plugin references smtpctl, which may require additional permissions to execute successfully.
+Depending on the user/group permissions of the telegraf user executing this plugin, you may need to alter the group membership, set facls, or use sudo.
+
+**Group membership (Recommended)**:
+```bash
+$ groups telegraf
+telegraf : telegraf
+
+$ usermod -a -G opensmtpd telegraf
+
+$ groups telegraf
+telegraf : telegraf opensmtpd
+```
+
+**Sudo privileges**:
+If you use this method, you will need the following in your telegraf config:
+```toml
+[[inputs.opensmtpd]]
+  use_sudo = true
+```
+
+You will also need to update your sudoers file:
+```bash
+$ visudo
+# Add the following line:
+telegraf ALL=(ALL) NOPASSWD: /usr/sbin/smtpctl
+```
+
+Please use the solution you see as most appropriate.
+
+### Example Output:
+
+```
+ telegraf --config etc/telegraf.conf --input-filter opensmtpd --test
+* Plugin: inputs.opensmtpd, Collection 1
+> opensmtpd,host=localhost scheduler_delivery_tempfail=822,mta_host=10,mta_task_running=4,queue_bounce=13017,scheduler_delivery_permfail=51022,mta_relay=7,queue_evpcache_size=2,scheduler_envelope_expired=26,bounce_message=0,mta_domain=7,queue_evpcache_update_hit=848,smtp_session_local=12294,bounce_envelope=0,queue_evpcache_load_hit=4389703,scheduler_ramqueue_update=0,mta_route=3,scheduler_delivery_ok=2149489,smtp_session_inet4=2131997,control_session=1,scheduler_envelope_incoming=0,uptime=10346728,scheduler_ramqueue_envelope=2,smtp_session=0,bounce_session=0,mta_envelope=2,mta_session=6,mta_task=2,scheduler_ramqueue_message=2,mta_connector=7,mta_source=1,scheduler_envelope=2,scheduler_envelope_inflight=2 1510220300000000000
+
+```

plugins/inputs/opensmtpd/opensmtpd.go

@@ -0,0 +1,134 @@
+package opensmtpd
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"os/exec"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/filter"
+	"github.com/influxdata/telegraf/internal"
+	"github.com/influxdata/telegraf/plugins/inputs"
+)
+
+type runner func(cmdName string, Timeout internal.Duration, UseSudo bool) (*bytes.Buffer, error)
+
+// Opensmtpd is used to store configuration values
+type Opensmtpd struct {
+	Binary  string
+	Timeout internal.Duration
+	UseSudo bool
+
+	filter filter.Filter
+	run    runner
+}
+
+var defaultBinary = "/usr/sbin/smtpctl"
+var defaultTimeout = internal.Duration{Duration: time.Second}
+
+var sampleConfig = `
+  ## If running as a restricted user you can prepend sudo for additional access:
+  #use_sudo = false
+
+  ## The default location of the smtpctl binary can be overridden with:
+  binary = "/usr/sbin/smtpctl"
+
+  ## The default timeout of 1000ms can be overriden with (in milliseconds):
+  timeout = 1000
+`
+
+func (s *Opensmtpd) Description() string {
+	return "A plugin to collect stats from Opensmtpd - a validating, recursive, and caching DNS resolver "
+}
+
+// SampleConfig displays configuration instructions
+func (s *Opensmtpd) SampleConfig() string {
+	return sampleConfig
+}
+
+// Shell out to opensmtpd_stat and return the output
+func opensmtpdRunner(cmdName string, Timeout internal.Duration, UseSudo bool) (*bytes.Buffer, error) {
+	cmdArgs := []string{"show", "stats"}
+
+	cmd := exec.Command(cmdName, cmdArgs...)
+
+	if UseSudo {
+		cmdArgs = append([]string{cmdName}, cmdArgs...)
+		cmd = exec.Command("sudo", cmdArgs...)
+	}
+
+	var out bytes.Buffer
+	cmd.Stdout = &out
+	err := internal.RunTimeout(cmd, Timeout.Duration)
+	if err != nil {
+		return &out, fmt.Errorf("error running smtpctl: %s", err)
+	}
+
+	return &out, nil
+}
+
+// Gather collects the configured stats from smtpctl and adds them to the
+// Accumulator
+//
+// All the dots in stat name will replaced by underscores. Histogram statistics will not be collected.
+func (s *Opensmtpd) Gather(acc telegraf.Accumulator) error {
+	// Always exclude uptime.human statistics
+	stat_excluded := []string{"uptime.human"}
+	filter_excluded, err := filter.Compile(stat_excluded)
+	if err != nil {
+		return err
+	}
+
+	out, err := s.run(s.Binary, s.Timeout, s.UseSudo)
+	if err != nil {
+		return fmt.Errorf("error gathering metrics: %s", err)
+	}
+
+	// Process values
+	fields := make(map[string]interface{})
+	scanner := bufio.NewScanner(out)
+	for scanner.Scan() {
+
+		cols := strings.Split(scanner.Text(), "=")
+
+		// Check split correctness
+		if len(cols) != 2 {
+			continue
+		}
+
+		stat := cols[0]
+		value := cols[1]
+
+		// Filter value
+		if filter_excluded.Match(stat) {
+			continue
+		}
+
+		field := strings.Replace(stat, ".", "_", -1)
+
+		fields[field], err = strconv.ParseFloat(value, 64)
+		if err != nil {
+			acc.AddError(fmt.Errorf("Expected a numerical value for %s = %v\n",
+				stat, value))
+		}
+	}
+
+	acc.AddFields("opensmtpd", fields, nil)
+
+	return nil
+}
+
+func init() {
+	inputs.Add("opensmtpd", func() telegraf.Input {
+		return &Opensmtpd{
+			run:     opensmtpdRunner,
+			Binary:  defaultBinary,
+			Timeout: defaultTimeout,
+			UseSudo: false,
+		}
+	})
+}

plugins/inputs/opensmtpd/opensmtpd_test.go

@@ -0,0 +1,111 @@
+package opensmtpd
+
+import (
+	"bytes"
+	"testing"
+	"time"
+
+	"github.com/influxdata/telegraf/internal"
+	"github.com/influxdata/telegraf/testutil"
+	"github.com/stretchr/testify/assert"
+)
+
+var TestTimeout = internal.Duration{Duration: time.Second}
+
+func SmtpCTL(output string, Timeout internal.Duration, useSudo bool) func(string, internal.Duration, bool) (*bytes.Buffer, error) {
+	return func(string, internal.Duration, bool) (*bytes.Buffer, error) {
+		return bytes.NewBuffer([]byte(output)), nil
+	}
+}
+
+func TestFilterSomeStats(t *testing.T) {
+	acc := &testutil.Accumulator{}
+	v := &Opensmtpd{
+		run: SmtpCTL(fullOutput, TestTimeout, false),
+	}
+	err := v.Gather(acc)
+
+	assert.NoError(t, err)
+	assert.True(t, acc.HasMeasurement("opensmtpd"))
+	assert.Equal(t, acc.NMetrics(), uint64(1))
+
+	assert.Equal(t, acc.NFields(), 36)
+	acc.AssertContainsFields(t, "opensmtpd", parsedFullOutput)
+}
+
+var parsedFullOutput = map[string]interface{}{
+	"bounce_envelope":             float64(0),
+	"bounce_message":              float64(0),
+	"bounce_session":              float64(0),
+	"control_session":             float64(1),
+	"mda_envelope":                float64(0),
+	"mda_pending":                 float64(0),
+	"mda_running":                 float64(0),
+	"mda_user":                    float64(0),
+	"mta_connector":               float64(1),
+	"mta_domain":                  float64(1),
+	"mta_envelope":                float64(0),
+	"mta_host":                    float64(6),
+	"mta_relay":                   float64(1),
+	"mta_route":                   float64(1),
+	"mta_session":                 float64(1),
+	"mta_source":                  float64(1),
+	"mta_task":                    float64(0),
+	"mta_task_running":            float64(5),
+	"queue_bounce":                float64(11495),
+	"queue_evpcache_load_hit":     float64(3927539),
+	"queue_evpcache_size":         float64(0),
+	"queue_evpcache_update_hit":   float64(508),
+	"scheduler_delivery_ok":       float64(1922951),
+	"scheduler_delivery_permfail": float64(45967),
+	"scheduler_delivery_tempfail": float64(493),
+	"scheduler_envelope":          float64(0),
+	"scheduler_envelope_expired":  float64(17),
+	"scheduler_envelope_incoming": float64(0),
+	"scheduler_envelope_inflight": float64(0),
+	"scheduler_ramqueue_envelope": float64(0),
+	"scheduler_ramqueue_message":  float64(0),
+	"scheduler_ramqueue_update":   float64(0),
+	"smtp_session":                float64(0),
+	"smtp_session_inet4":          float64(1903412),
+	"smtp_session_local":          float64(10827),
+	"uptime":                      float64(9253995),
+}
+
+var fullOutput = `bounce.envelope=0
+bounce.message=0
+bounce.session=0
+control.session=1
+mda.envelope=0
+mda.pending=0
+mda.running=0
+mda.user=0
+mta.connector=1
+mta.domain=1
+mta.envelope=0
+mta.host=6
+mta.relay=1
+mta.route=1
+mta.session=1
+mta.source=1
+mta.task=0
+mta.task.running=5
+queue.bounce=11495
+queue.evpcache.load.hit=3927539
+queue.evpcache.size=0
+queue.evpcache.update.hit=508
+scheduler.delivery.ok=1922951
+scheduler.delivery.permfail=45967
+scheduler.delivery.tempfail=493
+scheduler.envelope=0
+scheduler.envelope.expired=17
+scheduler.envelope.incoming=0
+scheduler.envelope.inflight=0
+scheduler.ramqueue.envelope=0
+scheduler.ramqueue.message=0
+scheduler.ramqueue.update=0
+smtp.session=0
+smtp.session.inet4=1903412
+smtp.session.local=10827
+uptime=9253995
+uptime.human=107d2h33m15s`