Enable xva builder to create VM from existing template

builder/xenserver/xva/builder.go

@@ -3,7 +3,6 @@ package xva
 import (
 	"context"
 	"errors"
-	"fmt"
 	"time"
 
 	"github.com/hashicorp/hcl/v2/hcldec"
@@ -74,8 +73,12 @@ func (self *Builder) Prepare(raws ...interface{}) (params []string, warns []stri
 
 	// Validation
 
-	if self.config.SourcePath == "" {
-		errs = packer.MultiErrorAppend(errs, fmt.Errorf("A source_path must be specified"))
+	if self.config.SourcePath == "" && self.config.CloneTemplate == "" {
+		errs = packer.MultiErrorAppend(
+			errs, errors.New("Either source_path or clone_template must be specified"))
+	} else if self.config.SourcePath != "" && self.config.CloneTemplate != "" {
+		errs = packer.MultiErrorAppend(
+			errs, errors.New("Only one of source_path and clone_template must be specified"))
 	}
 
 	if len(errs.Errors) > 0 {
@@ -134,6 +137,7 @@ func (self *Builder) Run(ctx context.Context, ui packer.Ui, hook packer.Hook) (p
 			VdiName:    self.config.ToolsIsoName,
 			VdiUuidKey: "tools_vdi_uuid",
 		},
+		new(stepCreateFromTemplate),
 		new(stepImportInstance),
 		&xscommon.StepAttachVdi{
 			VdiUuidKey: "floppy_vdi_uuid",

builder/xenserver/xva/step_create_from_template.go

@@ -0,0 +1,191 @@
+package xva
+
+import (
+	"context"
+	"fmt"
+	"log"
+
+	"github.com/hashicorp/packer-plugin-sdk/multistep"
+	"github.com/hashicorp/packer-plugin-sdk/packer"
+	xsclient "github.com/terra-farm/go-xen-api-client"
+	xscommon "github.com/xenserver/packer-builder-xenserver/builder/xenserver/common"
+)
+
+type stepCreateFromTemplate struct {
+	instance *xsclient.VMRef
+}
+
+func (self *stepCreateFromTemplate) Run(ctx context.Context, state multistep.StateBag) multistep.StepAction {
+
+	c := state.Get("client").(*xscommon.Connection)
+	config := state.Get("config").(xscommon.Config)
+	ui := state.Get("ui").(packer.Ui)
+
+	ui.Say("Step: Create Instance from Template")
+
+	if config.CloneTemplate == "" {
+		log.Println("Skipping creation from template - no `clone_template` configured.")
+		return multistep.ActionContinue
+	}
+
+	// Get the template to clone from
+
+	vms, err := c.GetClient().VM.GetByNameLabel(c.GetSessionRef(), config.CloneTemplate)
+
+	switch {
+	case len(vms) == 0:
+		ui.Error(fmt.Sprintf("Couldn't find a template with the name-label '%s'. Aborting.", config.CloneTemplate))
+		return multistep.ActionHalt
+	case len(vms) > 1:
+		ui.Error(fmt.Sprintf("Found more than one template with the name '%s'. The name must be unique. Aborting.", config.CloneTemplate))
+		return multistep.ActionHalt
+	}
+
+	template := vms[0]
+
+	// Clone that VM template
+	instance, err := c.GetClient().VM.Clone(c.GetSessionRef(), template, config.VMName)
+	if err != nil {
+		ui.Error(fmt.Sprintf("Error cloning VM: %s", err.Error()))
+		return multistep.ActionHalt
+	}
+	self.instance = &instance
+
+	err = c.GetClient().VM.SetIsATemplate(c.GetSessionRef(), instance, false)
+	if err != nil {
+		ui.Error(fmt.Sprintf("Error setting is_a_template=false: %s", err.Error()))
+		return multistep.ActionHalt
+	}
+
+	err = c.GetClient().VM.SetVCPUsMax(c.GetSessionRef(), instance, int(config.VCPUsMax))
+	if err != nil {
+		ui.Error(fmt.Sprintf("Error setting VM VCPUs Max=%d: %s", config.VCPUsMax, err.Error()))
+		return multistep.ActionHalt
+	}
+
+	err = c.GetClient().VM.SetVCPUsAtStartup(c.GetSessionRef(), instance, int(config.VCPUsAtStartup))
+	if err != nil {
+		ui.Error(fmt.Sprintf("Error setting VM VCPUs At Startup=%d: %s", config.VCPUsAtStartup, err.Error()))
+		return multistep.ActionHalt
+	}
+
+	memory := int(config.VMMemory * 1024 * 1024)
+	err = c.GetClient().VM.SetMemoryLimits(c.GetSessionRef(), instance, memory, memory, memory, memory)
+	if err != nil {
+		ui.Error(fmt.Sprintf("Error setting VM memory=%d: %s", memory, err.Error()))
+		return multistep.ActionHalt
+	}
+
+	err = c.GetClient().VM.SetPlatform(c.GetSessionRef(), instance, config.PlatformArgs)
+	if err != nil {
+		ui.Error(fmt.Sprintf("Error setting VM platform: %s", err.Error()))
+		return multistep.ActionHalt
+	}
+
+	err = c.GetClient().VM.SetNameDescription(c.GetSessionRef(), instance, config.VMDescription)
+	if err != nil {
+		ui.Error(fmt.Sprintf("Error setting VM description: %s", err.Error()))
+		return multistep.ActionHalt
+	}
+
+	// Connect Network
+
+	var network xsclient.NetworkRef
+
+	if len(config.NetworkNames) == 0 {
+		// No network has be specified. Use the management interface
+		log.Println("No network name given, attempting to use management interface")
+		pifs, err := c.GetClient().PIF.GetAll(c.GetSessionRef())
+
+		if err != nil {
+			ui.Error(fmt.Sprintf("Error getting PIFs: %s", err.Error()))
+			return multistep.ActionHalt
+		}
+
+		for _, pif := range pifs {
+			pif_rec, err := c.GetClient().PIF.GetRecord(c.GetSessionRef(), pif)
+
+			if err != nil {
+				ui.Error(fmt.Sprintf("Error getting PIF record: %s", err.Error()))
+				return multistep.ActionHalt
+			}
+
+			if pif_rec.Management {
+				network = pif_rec.Network
+			}
+
+		}
+
+		if string(network) == "" {
+			ui.Error("Error: couldn't find management network. Aborting.")
+			return multistep.ActionHalt
+		}
+
+		log.Printf("Creating VIF on network '%s' on VM '%s'\n", network, instance)
+		_, err = xscommon.ConnectNetwork(c, network, instance, "0")
+
+		if err != nil {
+			ui.Error(fmt.Sprintf("Failed to create VIF with error: %v", err))
+			return multistep.ActionHalt
+		}
+
+	} else {
+		log.Printf("Using provided network names: %v\n", config.NetworkNames)
+		// Look up each network by it's name label
+		for i, networkNameLabel := range config.NetworkNames {
+			networks, err := c.GetClient().Network.GetByNameLabel(c.GetSessionRef(), networkNameLabel)
+
+			if err != nil {
+				ui.Error(fmt.Sprintf("Error occured getting Network by name-label: %s", err.Error()))
+				return multistep.ActionHalt
+			}
+
+			switch {
+			case len(networks) == 0:
+				ui.Error(fmt.Sprintf("Couldn't find a network with the specified name-label '%s'. Aborting.", networkNameLabel))
+				return multistep.ActionHalt
+			case len(networks) > 1:
+				ui.Error(fmt.Sprintf("Found more than one network with the name '%s'. The name must be unique. Aborting.", networkNameLabel))
+				return multistep.ActionHalt
+			}
+
+			//we need the VIF index string
+			vifIndexString := fmt.Sprintf("%d", i)
+			_, err = xscommon.ConnectNetwork(c, networks[0], instance, vifIndexString)
+
+			if err != nil {
+				ui.Say(fmt.Sprintf("Failed to connect VIF with error: %v", err.Error()))
+			}
+		}
+	}
+
+	instanceId, err := c.GetClient().VM.GetUUID(c.GetSessionRef(), instance)
+	if err != nil {
+		ui.Error(fmt.Sprintf("Unable to get VM UUID: %s", err.Error()))
+		return multistep.ActionHalt
+	}
+
+	state.Put("instance_uuid", instanceId)
+	ui.Say(fmt.Sprintf("Created instance '%s'", instanceId))
+
+	return multistep.ActionContinue
+}
+
+func (self *stepCreateFromTemplate) Cleanup(state multistep.StateBag) {
+	config := state.Get("config").(xscommon.Config)
+	if config.ShouldKeepVM(state) {
+		return
+	}
+
+	ui := state.Get("ui").(packer.Ui)
+	c := state.Get("client").(*xscommon.Connection)
+
+	if self.instance != nil {
+		ui.Say("Destroying VM")
+		_ = c.GetClient().VM.HardShutdown(c.GetSessionRef(), *self.instance) // redundant, just in case
+		err := c.GetClient().VM.Destroy(c.GetSessionRef(), *self.instance)
+		if err != nil {
+			ui.Error(err.Error())
+		}
+	}
+}

builder/xenserver/xva/step_import_instance.go

@@ -3,6 +3,7 @@ package xva
 import (
 	"context"
 	"fmt"
+	"log"
 	"os"
 
 	"github.com/hashicorp/packer-plugin-sdk/multistep"
@@ -24,6 +25,11 @@ func (self *stepImportInstance) Run(ctx context.Context, state multistep.StateBa
 
 	ui.Say("Step: Import Instance")
 
+	if config.SourcePath == "" {
+		log.Println("Skipping imporing instance - no `source_path` configured.")
+		return multistep.ActionContinue
+	}
+
 	// find the SR
 	srs, err := c.GetClient().SR.GetAll(c.GetSessionRef())
 	sr := srs[0]