builder/vmware: Support reading guest IP from DHCP

builder/vmware/guest_ip.go

 package vmware
 
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"regexp"
+	"strings"
+	"time"
+)
+
 // Interface to help find the IP address of a running virtual machine.
 type GuestIPFinder interface {
 	GuestIP() (string, error)
@@ -9,12 +18,55 @@ type GuestIPFinder interface {
 // lease information from the VMware network devices.
 type DHCPLeaseGuestLookup struct {
 	// Device that the guest is connected to.
-	Device     string
+	Device string
 
 	// MAC address of the guest.
 	MACAddress string
 }
 
 func (f *DHCPLeaseGuestLookup) GuestIP() (string, error) {
-	return "", nil
+	fh, err := os.Open(fmt.Sprintf("/var/db/vmware/vmnet-dhcpd-%s.leases", f.Device))
+	if err != nil {
+		return "", err
+	}
+	defer fh.Close()
+
+	dhcpBytes, err := ioutil.ReadAll(fh)
+	if err != nil {
+		return "", err
+	}
+
+	var lastIp string
+	var lastLeaseEnd time.Time
+
+	var curIp string
+	var curLeaseEnd time.Time
+
+	ipLineRe := regexp.MustCompile(`^lease (.+?) {$`)
+	endTimeLineRe := regexp.MustCompile(`^\s*ends \d (.+?);$`)
+	macLineRe := regexp.MustCompile(`^\s*hardware ethernet (.+?);$`)
+
+	for _, line := range strings.Split(string(dhcpBytes), "\n") {
+		matches := ipLineRe.FindStringSubmatch(line)
+		if matches != nil {
+			lastIp = matches[1]
+			continue
+		}
+
+		matches = endTimeLineRe.FindStringSubmatch(line)
+		if matches != nil {
+			lastLeaseEnd, _ = time.Parse("2006/01/02 15:04:05", matches[1])
+			continue
+		}
+
+		// If the mac address matches and this lease ends farther in the
+		// future than the last match we might have, then choose it.
+		matches = macLineRe.FindStringSubmatch(line)
+		if matches != nil && matches[1] == f.MACAddress && curLeaseEnd.Before(lastLeaseEnd) {
+			curIp = lastIp
+			curLeaseEnd = lastLeaseEnd
+		}
+	}
+
+	return curIp, nil
 }

builder/vmware/step_wait_for_ssh.go

 package vmware
 
 import (
+	"errors"
 	"github.com/mitchellh/multistep"
 	"github.com/mitchellh/packer/packer"
+	"io/ioutil"
+	"log"
+	"os"
+	"time"
 )
 
 // This step waits for SSH to become available and establishes an SSH
@@ -11,21 +16,63 @@ import (
 // Uses:
 //   config *config
 //   ui     packer.Ui
+//   vmx_path string
 //
 // Produces:
 //   <nothing>
 type stepWaitForSSH struct{}
 
-func (stepWaitForSSH) Run(state map[string]interface{}) multistep.StepAction {
+func (s *stepWaitForSSH) Run(state map[string]interface{}) multistep.StepAction {
 	ui := state["ui"].(packer.Ui)
+	vmxPath := state["vmx_path"].(string)
 
 	ui.Say("Waiting for SSH to become available...")
-
 	for {
+		time.Sleep(5 * time.Second)
+
+		log.Println("Lookup up IP information...")
 		// First we wait for the IP to become available...
+		ipLookup, err := s.dhcpLeaseLookup(vmxPath)
+		if err != nil {
+			log.Printf("Can't lookup via DHCP lease: %s", err)
+		}
+
+		ip, err := ipLookup.GuestIP()
+		if err != nil {
+			log.Printf("IP lookup failed: %s", err)
+			continue
+		}
+
+		log.Printf("Detected IP: %s", ip)
 	}
 
 	return multistep.ActionContinue
 }
 
-func (stepWaitForSSH) Cleanup(map[string]interface{}) {}
+func (s *stepWaitForSSH) Cleanup(map[string]interface{}) {}
+
+// Reads the network information for lookup via DHCP.
+func (s *stepWaitForSSH) dhcpLeaseLookup(vmxPath string) (GuestIPFinder, error) {
+	f, err := os.Open(vmxPath)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	vmxBytes, err := ioutil.ReadAll(f)
+	if err != nil {
+		return nil, err
+	}
+
+	vmxData := ParseVMX(string(vmxBytes))
+
+	var ok bool
+	macAddress := ""
+	if macAddress, ok = vmxData["ethernet0.address"]; !ok || macAddress == "" {
+		if macAddress, ok = vmxData["ethernet0.generatedAddress"]; !ok || macAddress == "" {
+			return nil, errors.New("couldn't find MAC address in VMX")
+		}
+	}
+
+	return &DHCPLeaseGuestLookup{"vmnet8", macAddress}, nil
+}