builder/vmware: check for ifconfig in /sbin [GH-591]

CHANGELOG.md

@@ -22,6 +22,7 @@ BUG FIXES:
   [GH-554]
 * builder/openstack: Properly scrub password from logs [GH-554]
 * builder/virtualbox: No panic if SSH host port min/max is the same. [GH-594]
+* builder/vmware: checks if `ifconfig` is in `/sbin` [GH-591]
 * builder/vmware: Host IP lookup works for non-C locales. [GH-592]
 * common/uuid: Use cryptographically secure PRNG when generating
   UUIDs. [GH-552]

builder/vmware/host_ip_ifconfig.go

@@ -3,6 +3,7 @@ package vmware
 import (
 	"bytes"
 	"errors"
+	"os"
 	"os/exec"
 	"regexp"
 )
@@ -13,9 +14,20 @@ type IfconfigIPFinder struct {
 }
 
 func (f *IfconfigIPFinder) HostIP() (string, error) {
-	ifconfigPath, err := exec.LookPath("ifconfig")
-	if err != nil {
-		return "", err
+	var ifconfigPath string
+
+	// On some systems, ifconfig is in /sbin which is generally not
+	// on the PATH for a standard user, so we just check that first.
+	if _, err := os.Stat("/sbin/ifconfig"); err == nil {
+		ifconfigPath = "/sbin/ifconfig"
+	}
+
+	if ifconfigPath == "" {
+		var err error
+		ifconfigPath, err = exec.LookPath("ifconfig")
+		if err != nil {
+			return "", err
+		}
 	}
 
 	stdout := new(bytes.Buffer)