feat: check ovftool version

Checks the minimum recommended version of VMware Open Virtualization Format Tool ('ovftool').

Ref: #135

Signed-off-by: Ryan Johnson <ryan.johnson@broadcom.com>

.web-docs/components/builder/iso/README.md

@@ -875,6 +875,18 @@ provisioner](/packer/docs/provisioner/file).
 <!-- End of code generated from the comments of the ExportConfig struct in builder/vmware/common/export_config.go; -->
 
 
+HCL Example:
+
+```hcl
+source "vmware-iso" "example" {
+  # ... omitted for brevity ...
+	format          = "ova"
+	ovftool_options = ["--compress=9", "--makeDeltaDisks"]
+	skip_export     = false
+	keep_registered = false
+	skip_compaction = true
+```
+
 ### Communicator configuration
 
 #### Optional common fields:

.web-docs/components/builder/vmx/README.md

@@ -421,6 +421,16 @@ boot time.
 <!-- End of code generated from the comments of the ExportConfig struct in builder/vmware/common/export_config.go; -->
 
 
+HCL Example:
+
+```hcl
+	format          = "ova"
+	ovftool_options = ["--compress=9", "--makeDeltaDisks"]
+	skip_export     = false
+	keep_registered = false
+	skip_compaction = true
+```
+
 ### Output configuration
 
 #### Optional:

builder/vmware/common/driver.go

@@ -18,9 +18,17 @@ import (
 	"strings"
 	"time"
 
+	"github.com/hashicorp/go-version"
 	"github.com/hashicorp/packer-plugin-sdk/multistep"
 )
 
+// Sets the minimum recommended version of the VMware OVF Tool.
+// https://developer.broadcom.com/tools/open-virtualization-format-ovf-tool/latest
+const minimumRecommendOvfToolVersion = "4.6.0"
+
+// A regex to match the version of the VMware OVF Tool.
+var ovfToolVersionRegex = regexp.MustCompile(`\d+\.\d+\.\d+`)
+
 // A driver is able to talk to VMware, control virtual machines, etc.
 type Driver interface {
 	// Clone clones the VMX and the disk to the destination path. The
@@ -630,10 +638,10 @@ func (d *VmwareDriver) HostIP(state multistep.StateBag) (string, error) {
 	return "", fmt.Errorf("unable to find host IP from devices %v, last error: %s", devices, lastError)
 }
 
-func GetOVFTool() string {
+func GetOvfTool() string {
 	ovftool := "ovftool"
 	if runtime.GOOS == "windows" {
-		ovftool = "ovftool.exe"
+		ovftool += ".exe"
 	}
 
 	if _, err := exec.LookPath(ovftool); err != nil {
@@ -642,8 +650,47 @@ func GetOVFTool() string {
 	return ovftool
 }
 
+// CheckOvfToolVersion checks the version of the VMware OVF Tool.
+func CheckOvfToolVersion(ovftoolPath string) (bool, error) {
+	output, err := exec.Command(ovftoolPath, "--version").CombinedOutput()
+	if err != nil {
+		log.Printf("[WARN] Error running 'ovftool --version': %v.", err)
+		log.Printf("[WARN] Returned: %s", string(output))
+		return false, errors.New("failed to execute ovftool")
+	}
+	versionOutput := string(output)
+	log.Printf("Returned ovftool version: %s.", versionOutput)
+
+	fields := strings.Fields(versionOutput)
+	for _, field := range fields {
+		if ovfToolVersionRegex.MatchString(field) {
+			currentVersion, err := version.NewVersion(field)
+			if err != nil {
+				log.Printf("[WARN] Failed to parse version '%s': %v.", field, err)
+				return false, errors.New("failed to parse version")
+			}
+
+			minimumVersion, err := version.NewVersion(minimumRecommendOvfToolVersion)
+			if err != nil {
+				log.Printf("[WARN] Failed to parse minimum recommended version '%s': %v", minimumRecommendOvfToolVersion, err)
+				return false, errors.New("failed to parse minimum recommended version")
+			}
+
+			if currentVersion.LessThan(minimumVersion) {
+				log.Printf("[WARN] The version of ovftool (%s) is below the minimum recommended version (%s).", currentVersion, minimumVersion)
+				return false, errors.New("ovftool version is below the minimum recommended version")
+			}
+
+			return true, nil
+		}
+	}
+
+	log.Printf("[WARN] Unable to determine the version of ovftool.")
+	return false, errors.New("unable to determine the version of ovftool")
+}
+
 func (d *VmwareDriver) Export(args []string) error {
-	ovftool := GetOVFTool()
+	ovftool := GetOvfTool()
 	if ovftool == "" {
 		return fmt.Errorf("error finding ovftool in path")
 	}
@@ -661,13 +708,15 @@ func (d *VmwareDriver) VerifyOvfTool(SkipExport, _ bool) error {
 	}
 
 	log.Printf("Verifying that ovftool exists...")
-	// Validate that tool exists, but no need to validate credentials.
-	ovftool := GetOVFTool()
-	if ovftool != "" {
-		return nil
-	} else {
-		return fmt.Errorf("ovftool not found in path. either set " +
-			"'skip_export = true', remove 'format' option, or install ovftool")
+	ovftoolPath := GetOvfTool()
+	if ovftoolPath == "" {
+		return fmt.Errorf("ovftool not found; install and include it in your PATH")
 	}
 
+	log.Printf("Checking ovftool version...")
+	if !CheckOvfToolVersion(ovftoolPath) {
+		log.Printf("[WARN] ovftool does not meet the minimum recommended version: %s", minimumRecommendOvfToolVersion)
+	}
+
+	return nil
 }

builder/vmware/common/driver_esx5.go

@@ -355,7 +355,7 @@ func (d *ESX5Driver) VerifyOvfTool(SkipExport, skipValidateCredentials bool) err
 	// check that password is valid by sending a dummy ovftool command
 	// now, so that we don't fail for a simple mistake after a long
 	// build
-	ovftool := GetOVFTool()
+	ovftool := GetOvfTool()
 
 	if d.Password == "" {
 		return fmt.Errorf("exporting the vm from esxi with ovftool requires " +

builder/vmware/common/step_export.go

@@ -93,7 +93,7 @@ func (s *StepExport) Run(ctx context.Context, state multistep.StateBag) multiste
 
 	var args, ui_args []string
 
-	ovftool := GetOVFTool()
+	ovftool := GetOvfTool()
 	if c.RemoteType == "esx5" {
 		// Generate arguments for the ovftool command, but obfuscating the
 		// password that we can log the command to the UI for debugging.

docs/builders/iso.mdx

@@ -179,6 +179,18 @@ necessary for this build to succeed and can be found further down the page.
 
 @include 'builder/vmware/common/ExportConfig-not-required.mdx'
 
+HCL Example:
+
+```hcl
+source "vmware-iso" "example" {
+  # ... omitted for brevity ...
+	format          = "ova"
+	ovftool_options = ["--compress=9", "--makeDeltaDisks"]
+	skip_export     = false
+	keep_registered = false
+	skip_compaction = true
+```
+
 ### Communicator configuration
 
 #### Optional common fields:

docs/builders/vmx.mdx

@@ -130,6 +130,16 @@ necessary for this build to succeed and can be found further down the page.
 
 @include 'builder/vmware/common/ExportConfig-not-required.mdx'
 
+HCL Example:
+
+```hcl
+	format          = "ova"
+	ovftool_options = ["--compress=9", "--makeDeltaDisks"]
+	skip_export     = false
+	keep_registered = false
+	skip_compaction = true
+```
+
 ### Output configuration
 
 #### Optional: