allow querying sensors via the open interface

closes #2244
closes #1547

plugins/inputs/ipmi_sensor/ipmi.go

@@ -1,48 +1,62 @@
 package ipmi_sensor
 
 import (
+	"fmt"
+	"os/exec"
 	"strconv"
 	"strings"
 	"time"
 
 	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/internal"
 	"github.com/influxdata/telegraf/plugins/inputs"
 )
 
+var (
+	execCommand = exec.Command // execCommand is used to mock commands in tests.
+)
+
 type Ipmi struct {
+	path    string
 	Servers []string
-	runner  Runner
 }
 
 var sampleConfig = `
-  ## specify servers via a url matching:
+  ## optionally specify the path to the ipmitool executable
+  # path = "/usr/bin/ipmitool"
+  #
+  ## optionally specify one or more servers via a url matching
   ##  [username[:password]@][protocol[(address)]]
   ##  e.g.
   ##    root:passwd@lan(127.0.0.1)
   ##
-  servers = ["USERID:PASSW0RD@lan(192.168.1.1)"]
+  ## if no servers are specified, local machine sensor stats will be queried
+  ##
+  # servers = ["USERID:PASSW0RD@lan(192.168.1.1)"]
 `
 
-func NewIpmi() *Ipmi {
-	return &Ipmi{
-		runner: CommandRunner{},
-	}
-}
-
 func (m *Ipmi) SampleConfig() string {
 	return sampleConfig
 }
 
 func (m *Ipmi) Description() string {
-	return "Read metrics from one or many bare metal servers"
+	return "Read metrics from the bare metal servers via IPMI"
 }
 
 func (m *Ipmi) Gather(acc telegraf.Accumulator) error {
-	if m.runner == nil {
-		m.runner = CommandRunner{}
+	if len(m.path) == 0 {
+		return fmt.Errorf("ipmitool not found: verify that ipmitool is installed and that ipmitool is in your PATH")
 	}
-	for _, serv := range m.Servers {
-		err := m.gatherServer(serv, acc)
+
+	if len(m.Servers) > 0 {
+		for _, server := range m.Servers {
+			err := m.parse(acc, server)
+			if err != nil {
+				return err
+			}
+		}
+	} else {
+		err := m.parse(acc, "")
 		if err != nil {
 			return err
 		}
@@ -51,17 +65,26 @@ func (m *Ipmi) Gather(acc telegraf.Accumulator) error {
 	return nil
 }
 
-func (m *Ipmi) gatherServer(serv string, acc telegraf.Accumulator) error {
-	conn := NewConnection(serv)
+func (m *Ipmi) parse(acc telegraf.Accumulator, server string) error {
+	opts := make([]string, 0)
+	hostname := ""
 
-	res, err := m.runner.Run(conn, "sdr")
+	if server != "" {
+		conn := NewConnection(server)
+		hostname = conn.Hostname
+		opts = conn.options()
+	}
+
+	opts = append(opts, "sdr")
+	cmd := execCommand(m.path, opts...)
+	out, err := internal.CombinedOutputTimeout(cmd, time.Second*5)
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to run command %s: %s - %s", strings.Join(cmd.Args, " "), err, string(out))
 	}
 
 	// each line will look something like
 	// Planar VBAT      | 3.05 Volts        | ok
-	lines := strings.Split(res, "\n")
+	lines := strings.Split(string(out), "\n")
 	for i := 0; i < len(lines); i++ {
 		vals := strings.Split(lines[i], "|")
 		if len(vals) != 3 {
@@ -69,8 +92,12 @@ func (m *Ipmi) gatherServer(serv string, acc telegraf.Accumulator) error {
 		}
 
 		tags := map[string]string{
-			"server": conn.Hostname,
-			"name":   transform(vals[0]),
+			"name": transform(vals[0]),
+		}
+
+		// tag the server is we have one
+		if hostname != "" {
+			tags["server"] = hostname
 		}
 
 		fields := make(map[string]interface{})
@@ -99,10 +126,6 @@ func (m *Ipmi) gatherServer(serv string, acc telegraf.Accumulator) error {
 	return nil
 }
 
-type Runner interface {
-	Run(conn *Connection, args ...string) (string, error)
-}
-
 func Atofloat(val string) float64 {
 	f, err := strconv.ParseFloat(val, 64)
 	if err != nil {
@@ -123,7 +146,12 @@ func transform(s string) string {
 }
 
 func init() {
+	m := Ipmi{}
+	path, _ := exec.LookPath("ipmitool")
+	if len(path) > 0 {
+		m.path = path
+	}
 	inputs.Add("ipmi_sensor", func() telegraf.Input {
-		return &Ipmi{}
+		return &m
 	})
 }