Exporting Ipmi.Path to be set by config. (#2498)

* Exporting Ipmi.Path to be set by config.

Currently "path" is not exported, giving this error when users try to
override the variable via telegraf.conf as per the sample config:

`field corresponding to `path' is not defined in `*ipmi_sensor.Ipmi'`

Exporting the variable solves the problem.

* Updating changelog.

plugins/inputs/ipmi_sensor/ipmi.go

@@ -17,7 +17,7 @@ var (
 )
 
 type Ipmi struct {
-	path    string
+	Path    string
 	Servers []string
 }
 
@@ -44,7 +44,7 @@ func (m *Ipmi) Description() string {
 }
 
 func (m *Ipmi) Gather(acc telegraf.Accumulator) error {
-	if len(m.path) == 0 {
+	if len(m.Path) == 0 {
 		return fmt.Errorf("ipmitool not found: verify that ipmitool is installed and that ipmitool is in your PATH")
 	}
 
@@ -76,7 +76,7 @@ func (m *Ipmi) parse(acc telegraf.Accumulator, server string) error {
 	}
 
 	opts = append(opts, "sdr")
-	cmd := execCommand(m.path, opts...)
+	cmd := execCommand(m.Path, opts...)
 	out, err := internal.CombinedOutputTimeout(cmd, time.Second*5)
 	if err != nil {
 		return fmt.Errorf("failed to run command %s: %s - %s", strings.Join(cmd.Args, " "), err, string(out))
@@ -149,7 +149,7 @@ func init() {
 	m := Ipmi{}
 	path, _ := exec.LookPath("ipmitool")
 	if len(path) > 0 {
-		m.path = path
+		m.Path = path
 	}
 	inputs.Add("ipmi_sensor", func() telegraf.Input {
 		return &m

plugins/inputs/ipmi_sensor/ipmi_test.go

@@ -14,7 +14,7 @@ import (
 func TestGather(t *testing.T) {
 	i := &Ipmi{
 		Servers: []string{"USERID:PASSW0RD@lan(192.168.1.1)"},
-		path:    "ipmitool",
+		Path:    "ipmitool",
 	}
 	// overwriting exec commands with mock commands
 	execCommand = fakeExecCommand
@@ -118,7 +118,7 @@ func TestGather(t *testing.T) {
 	}
 
 	i = &Ipmi{
-		path: "ipmitool",
+		Path: "ipmitool",
 	}
 
 	err = i.Gather(&acc)