Using vmconnect to display gui for hyper-v

vmconnect.exe comes as part of Hyper-V and is the tool used by Hyper-V Manager to connect with a virtual machine. This commits sets behaviour the same as virtualbox and vmware to display the virtual machine connection unless headless is set in the template.

builder/hyperv/common/driver.go

@@ -1,5 +1,9 @@
 package common
 
+import (
+	"context"
+)
+
 // A driver is able to talk to HyperV and perform certain
 // operations with it. Some of the operations on here may seem overly
 // specific, but they were built specifically in mind to handle features
@@ -109,4 +113,10 @@ type Driver interface {
 	MountFloppyDrive(string, string) error
 
 	UnmountFloppyDrive(string) error
+
+	// Connect connects to a VM specified by the name given.
+	Connect(string) context.CancelFunc
+
+	// Disconnect disconnects to a VM specified by the context cancel function.
+	Disconnect(context.CancelFunc)
 }

builder/hyperv/common/driver_mock.go

@@ -1,5 +1,9 @@
 package common
 
+import (
+	"context"
+)
+
 type DriverMock struct {
 	IsRunning_Called bool
 	IsRunning_VmName string
@@ -240,6 +244,13 @@ type DriverMock struct {
 	UnmountFloppyDrive_Called bool
 	UnmountFloppyDrive_VmName string
 	UnmountFloppyDrive_Err    error
+
+	Connect_Called bool
+	Connect_VmName string
+	Connect_Cancel context.CancelFunc
+
+	Disconnect_Called bool
+	Disconnect_Cancel context.CancelFunc
 }
 
 func (d *DriverMock) IsRunning(vmName string) (bool, error) {
@@ -553,3 +564,14 @@ func (d *DriverMock) UnmountFloppyDrive(vmName string) error {
 	d.UnmountFloppyDrive_VmName = vmName
 	return d.UnmountFloppyDrive_Err
 }
+
+func (d *DriverMock) Connect(vmName string) context.CancelFunc {
+	d.Connect_Called = true
+	d.Connect_VmName = vmName
+	return d.Connect_Cancel
+}
+
+func (d *DriverMock) Disconnect(cancel context.CancelFunc) {
+	d.Disconnect_Called = true
+	d.Disconnect_Cancel = cancel
+}

builder/hyperv/common/driver_ps_4.go

@@ -1,6 +1,7 @@
 package common
 
 import (
+	"context"
 	"fmt"
 	"log"
 	"runtime"
@@ -347,3 +348,14 @@ func (d *HypervPS4Driver) verifyHypervPermissions() error {
 
 	return nil
 }
+
+// Connect connects to a VM specified by the name given.
+func (d *HypervPS4Driver) Connect(vmName string) context.CancelFunc {
+	return hyperv.ConnectVirtualMachine(vmName)
+}
+
+// Disconnect disconnects to a VM specified by calling the context cancel function returned
+// from Connect.
+func (d *HypervPS4Driver) Disconnect(cancel context.CancelFunc) {
+	hyperv.DisconnectVirtualMachine(cancel)
+}

builder/hyperv/common/step_run.go

@@ -9,7 +9,8 @@ import (
 )
 
 type StepRun struct {
-	vmName string
+	Headless bool
+	vmName   string
 }
 
 func (s *StepRun) Run(_ context.Context, state multistep.StateBag) multistep.StepAction {
@@ -29,6 +30,11 @@ func (s *StepRun) Run(_ context.Context, state multistep.StateBag) multistep.Ste
 
 	s.vmName = vmName
 
+	if !s.Headless {
+		ui.Say("Connecting to vmconnect...")
+		cancel := driver.Connect(vmName)
+		state.Put("guiCancelFunc", cancel)
+	}
 	return multistep.ActionContinue
 }
 
@@ -39,6 +45,12 @@ func (s *StepRun) Cleanup(state multistep.StateBag) {
 
 	driver := state.Get("driver").(Driver)
 	ui := state.Get("ui").(packer.Ui)
+	guiCancelFunc := state.Get("guiCancelFunc").(context.CancelFunc)
+
+	if guiCancelFunc != nil {
+		ui.Say("Disconnecting from vmconnect...")
+		guiCancelFunc()
+	}
 
 	if running, _ := driver.IsRunning(s.vmName); running {
 		if err := driver.Stop(s.vmName); err != nil {

builder/hyperv/iso/builder.go

@@ -115,6 +115,8 @@ type Config struct {
 	// Create the VM with a Fixed VHD format disk instead of Dynamic VHDX
 	FixedVHD bool `mapstructure:"use_fixed_vhd_format"`
 
+	Headless bool `mapstructure:"headless"`
+
 	ctx interpolate.Context
 }
 
@@ -427,7 +429,9 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 			SwitchVlanId: b.config.SwitchVlanId,
 		},
 
-		&hypervcommon.StepRun{},
+		&hypervcommon.StepRun{
+			Headless: b.config.Headless,
+		},
 
 		&hypervcommon.StepTypeBootCommand{
 			BootCommand: b.config.FlatBootCommand(),

builder/hyperv/vmcx/builder.go

@@ -98,6 +98,8 @@ type Config struct {
 
 	SkipExport bool `mapstructure:"skip_export"`
 
+	Headless bool `mapstructure:"headless"`
+
 	ctx interpolate.Context
 }
 
@@ -436,7 +438,9 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 			SwitchVlanId: b.config.SwitchVlanId,
 		},
 
-		&hypervcommon.StepRun{},
+		&hypervcommon.StepRun{
+			Headless: b.config.Headless,
+		},
 
 		&hypervcommon.StepTypeBootCommand{
 			BootCommand: b.config.FlatBootCommand(),

common/powershell/hyperv/hyperv.go

@@ -1,7 +1,9 @@
 package hyperv
 
 import (
+	"context"
 	"errors"
+	"os/exec"
 	"strconv"
 	"strings"
 
@@ -1244,3 +1246,14 @@ param([string]$vmName, [string]$scanCodes)
 	err := ps.Run(script, vmName, scanCodes)
 	return err
 }
+
+func ConnectVirtualMachine(vmName string) context.CancelFunc {
+	ctx, cancel := context.WithCancel(context.Background())
+	cmd := exec.CommandContext(ctx, "vmconnect.exe", "localhost", vmName)
+	cmd.Start()
+	return cancel
+}
+
+func DisconnectVirtualMachine(cancel context.CancelFunc) {
+	cancel()
+}

website/source/docs/builders/hyperv-iso.html.md.erb

@@ -102,6 +102,11 @@ can be configured for this builder.
 -   `differencing_disk` (boolean) - If true enables differencing disks. Only the changes will be written to the new disk. This is especially useful if your
     source is a vhd/vhdx. This defaults to false.
 
+-   `headless` (boolean) - Packer defaults to building Hyper-V virtual
+    machines by launching a GUI that shows the console of the machine
+    being built. When this value is set to true, the machine will start without
+    a console.
+
 -   `skip_export` (boolean) - If true skips VM export. If you are interested only in the vhd/vhdx files, you can enable this option. This will create
     inline disks which improves the build performance. There will not be any copying of source vhds to temp directory. This defaults to false.
 

website/source/docs/builders/hyperv-vmcx.html.md.erb

@@ -139,6 +139,11 @@ can be configured for this builder.
 -   `guest_additions_path` (string) - The path to the iso image for guest
     additions.
 
+-   `headless` (boolean) - Packer defaults to building Hyper-V virtual
+    machines by launching a GUI that shows the console of the machine
+    being built. When this value is set to true, the machine will start without
+    a console.
+
 -   `http_directory` (string) - Path to a directory to serve using an HTTP
     server. The files in this directory will be available over HTTP that will
     be requestable from the virtual machine. This is useful for hosting