builder/parallels: Use most recent DHCP lease when determening IP.

Fixes #1746. Problem establishing SSH connection with Fedora 21 and
Parallels

builder/parallels/common/driver.go

@@ -55,6 +55,7 @@ func NewDriver() (Driver, error) {
 	var drivers map[string]Driver
 	var prlctlPath string
 	var supportedVersions []string
+	dhcp_lease_file := "/Library/Preferences/Parallels/parallels_dhcp_leases"
 
 	if runtime.GOOS != "darwin" {
 		return nil, fmt.Errorf(
@@ -75,10 +76,12 @@ func NewDriver() (Driver, error) {
 		"10": &Parallels10Driver{
 			Parallels9Driver: Parallels9Driver{
 				PrlctlPath:      prlctlPath,
+				dhcp_lease_file: dhcp_lease_file,
 			},
 		},
 		"9": &Parallels9Driver{
 			PrlctlPath:      prlctlPath,
+			dhcp_lease_file: dhcp_lease_file,
 		},
 	}
 

builder/parallels/common/driver_9.go

@@ -9,6 +9,7 @@ import (
 	"os/exec"
 	"path/filepath"
 	"regexp"
+	"strconv"
 	"strings"
 	"time"
 
@@ -18,6 +19,8 @@ import (
 type Parallels9Driver struct {
 	// This is the path to the "prlctl" application.
 	PrlctlPath string
+	// The path to the parallels_dhcp_leases file
+	dhcp_lease_file string
 }
 
 func (d *Parallels9Driver) Import(name, srcPath, dstDir string, reassignMac bool) error {
@@ -276,31 +279,43 @@ func (d *Parallels9Driver) Mac(vmName string) (string, error) {
 }
 
 // Finds the IP address of a VM connected that uses DHCP by its MAC address
+//
+// Parses the file /Library/Preferences/Parallels/parallels_dhcp_leases
+// file contain a list of DHCP leases given by Parallels Desktop
+// Example line:
+// 10.211.55.181="1418921112,1800,001c42f593fb,ff42f593fb000100011c25b9ff001c42f593fb"
+// IP Address   ="Lease expiry, Lease time, MAC, MAC or DUID"
 func (d *Parallels9Driver) IpAddress(mac string) (string, error) {
-	var stdout bytes.Buffer
-	dhcp_lease_file := "/Library/Preferences/Parallels/parallels_dhcp_leases"
 
 	if len(mac) != 12 {
 		return "", fmt.Errorf("Not a valid MAC address: %s. It should be exactly 12 digits.", mac)
 	}
 
-	cmd := exec.Command("grep", "-i", mac, dhcp_lease_file)
-	cmd.Stdout = &stdout
-	if err := cmd.Run(); err != nil {
+	leases, err := ioutil.ReadFile(d.dhcp_lease_file)
+	if err != nil {
 		return "", err
 	}
 
-	stdoutString := strings.TrimSpace(stdout.String())
-	re := regexp.MustCompile("(.*)=.*")
-	ipMatch := re.FindAllStringSubmatch(stdoutString, 1)
+	re := regexp.MustCompile("(.*)=\"(.*),(.*)," + strings.ToLower(mac) + ",.*\"")
+	mostRecentIp := ""
+	mostRecentLease := uint64(0)
+	for _, l := range re.FindAllStringSubmatch(string(leases), -1) {
+		ip := l[1]
+		expiry, _ := strconv.ParseUint(l[2], 10, 64)
+		leaseTime, _ := strconv.ParseUint(l[3], 10, 32)
+		log.Printf("Found lease: %s for MAC: %s, expiring at %d, leased for %d s.\n", ip, mac, expiry, leaseTime)
+		if mostRecentLease <= expiry-leaseTime {
+			mostRecentIp = ip
+			mostRecentLease = expiry - leaseTime
+		}
+	}
 
-	if len(ipMatch) != 1 {
-		return "", fmt.Errorf("IP lease not found for MAC address %s in: %s\n", mac, dhcp_lease_file)
+	if len(mostRecentIp) == 0 {
+		return "", fmt.Errorf("IP lease not found for MAC address %s in: %s\n", mac, d.dhcp_lease_file)
 	}
 
-	ip := ipMatch[0][1]
-	log.Printf("Found IP lease: %s for MAC address %s\n", ip, mac)
-	return ip, nil
+	log.Printf("Found IP lease: %s for MAC address %s\n", mostRecentIp, mac)
+	return mostRecentIp, nil
 }
 
 func (d *Parallels9Driver) ToolsIsoPath(k string) (string, error) {

builder/parallels/common/driver_9_test.go

 package common
 
 import (
+	"io/ioutil"
+	"os"
 	"testing"
 )
 
 func TestParallels9Driver_impl(t *testing.T) {
 	var _ Driver = new(Parallels9Driver)
 }
+
+func TestIpAddress(t *testing.T) {
+	tf, err := ioutil.TempFile("", "packer")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	defer os.Remove(tf.Name())
+
+	d := Parallels9Driver{
+		dhcp_lease_file: tf.Name(),
+	}
+
+	// No lease should be found in an empty file
+	ip, err := d.IpAddress("123456789012")
+	if err == nil {
+		t.Fatalf("Found IP: \"%v\". No IP should be found!\n", ip)
+	}
+
+	// The most recent lease, 10.211.55.126 should be found
+	c := []byte(`
+[vnic0]
+10.211.55.125="1418288000,1800,001c4235240c,ff4235240c000100011c1c10e7001c4235240c"
+10.211.55.126="1418288969,1800,001c4235240c,ff4235240c000100011c1c11ad001c4235240c"
+10.211.55.254="1411712008,1800,001c42a51419,01001c42a51419"
+`)
+	ioutil.WriteFile(tf.Name(), c, 0666)
+	ip, err = d.IpAddress("001C4235240c")
+	if err != nil {
+		t.Fatalf("Error: %v\n", err)
+	}
+	if ip != "10.211.55.126" {
+		t.Fatalf("Should have found 10.211.55.126, not %s!\n", ip)
+	}
+
+	// The most recent lease, 10.211.55.124 should be found
+	c = []byte(`[vnic0]
+10.211.55.124="1418288969,1800,001c4235240c,ff4235240c000100011c1c11ad001c4235240c"
+10.211.55.125="1418288000,1800,001c4235240c,ff4235240c000100011c1c10e7001c4235240c"
+10.211.55.254="1411712008,1800,001c42a51419,01001c42a51419"
+`)
+	ioutil.WriteFile(tf.Name(), c, 0666)
+	ip, err = d.IpAddress("001c4235240c")
+	if err != nil {
+		t.Fatalf("Error: %v\n", err)
+	}
+	if ip != "10.211.55.124" {
+		t.Fatalf("Should have found 10.211.55.124, not %s!\n", ip)
+	}
+}