✨ add VM naming strategy for VMs in govami mode

- Add VM naming stragey for vsphere vms and VMs in govami mode

apis/v1alpha3/vspheremachine_conversion.go

@@ -40,6 +40,7 @@ func (src *VSphereMachine) ConvertTo(dstRaw conversion.Hub) error {
 	dst.Spec.TagIDs = restored.Spec.TagIDs
 	dst.Spec.PowerOffMode = restored.Spec.PowerOffMode
 	dst.Spec.GuestSoftPowerOffTimeout = restored.Spec.GuestSoftPowerOffTimeout
+	dst.Spec.NamingStrategy = restored.Spec.NamingStrategy
 	for i := range dst.Spec.Network.Devices {
 		dst.Spec.Network.Devices[i].AddressesFromPools = restored.Spec.Network.Devices[i].AddressesFromPools
 		dst.Spec.Network.Devices[i].DHCP4Overrides = restored.Spec.Network.Devices[i].DHCP4Overrides

apis/v1alpha3/vspheremachinetemplate_conversion.go

@@ -43,6 +43,7 @@ func (src *VSphereMachineTemplate) ConvertTo(dstRaw conversion.Hub) error {
 	dst.Spec.Template.Spec.AdditionalDisksGiB = restored.Spec.Template.Spec.AdditionalDisksGiB
 	dst.Spec.Template.Spec.PowerOffMode = restored.Spec.Template.Spec.PowerOffMode
 	dst.Spec.Template.Spec.GuestSoftPowerOffTimeout = restored.Spec.Template.Spec.GuestSoftPowerOffTimeout
+	dst.Spec.Template.Spec.NamingStrategy = restored.Spec.Template.Spec.NamingStrategy
 	for i := range dst.Spec.Template.Spec.Network.Devices {
 		dst.Spec.Template.Spec.Network.Devices[i].AddressesFromPools = restored.Spec.Template.Spec.Network.Devices[i].AddressesFromPools
 		dst.Spec.Template.Spec.Network.Devices[i].DHCP4Overrides = restored.Spec.Template.Spec.Network.Devices[i].DHCP4Overrides

apis/v1alpha4/vspheremachine_conversion.go

@@ -40,6 +40,7 @@ func (src *VSphereMachine) ConvertTo(dstRaw conversion.Hub) error {
 	dst.Spec.TagIDs = restored.Spec.TagIDs
 	dst.Spec.PowerOffMode = restored.Spec.PowerOffMode
 	dst.Spec.GuestSoftPowerOffTimeout = restored.Spec.GuestSoftPowerOffTimeout
+	dst.Spec.NamingStrategy = restored.Spec.NamingStrategy
 	for i := range dst.Spec.Network.Devices {
 		dst.Spec.Network.Devices[i].AddressesFromPools = restored.Spec.Network.Devices[i].AddressesFromPools
 		dst.Spec.Network.Devices[i].DHCP4Overrides = restored.Spec.Network.Devices[i].DHCP4Overrides

apis/v1alpha4/vspheremachinetemplate_conversion.go

@@ -43,6 +43,7 @@ func (src *VSphereMachineTemplate) ConvertTo(dstRaw conversion.Hub) error {
 	dst.Spec.Template.Spec.AdditionalDisksGiB = restored.Spec.Template.Spec.AdditionalDisksGiB
 	dst.Spec.Template.Spec.PowerOffMode = restored.Spec.Template.Spec.PowerOffMode
 	dst.Spec.Template.Spec.GuestSoftPowerOffTimeout = restored.Spec.Template.Spec.GuestSoftPowerOffTimeout
+	dst.Spec.Template.Spec.NamingStrategy = restored.Spec.Template.Spec.NamingStrategy
 	for i := range dst.Spec.Template.Spec.Network.Devices {
 		dst.Spec.Template.Spec.Network.Devices[i].AddressesFromPools = restored.Spec.Template.Spec.Network.Devices[i].AddressesFromPools
 		dst.Spec.Template.Spec.Network.Devices[i].DHCP4Overrides = restored.Spec.Template.Spec.Network.Devices[i].DHCP4Overrides

apis/v1beta1/vspheremachine_types.go

@@ -68,6 +68,30 @@ type VSphereMachineSpec struct {
 	//
 	// +optional
 	GuestSoftPowerOffTimeout *metav1.Duration `json:"guestSoftPowerOffTimeout,omitempty"`
+
+	// NamingStrategy allows configuring the naming strategy used when calculating the name of the VirtualMachine.
+	// +optional
+	NamingStrategy *VirtualMachineNamingStrategy `json:"namingStrategy,omitempty"`
+}
+
+// VirtualMachineNamingStrategy defines the naming strategy for the VirtualMachines.
+type VirtualMachineNamingStrategy struct {
+	// Template defines the template to use for generating the name of the VirtualMachine object.
+	// If not defined, it will fall back to `{{ .machine.name }}`.
+	// The templating has the following data available:
+	// * `.machine.name`: The name of the Machine object.
+	// The templating also has the following funcs available:
+	// * `trimSuffix`: same as strings.TrimSuffix
+	// * `trunc`: truncates a string, e.g. `trunc 2 "hello"` or `trunc -2 "hello"`
+	// Notes:
+	// * While the template offers some flexibility, we would like the name to link to the Machine name
+	//   to ensure better user experience when troubleshooting
+	// * Generated names must be valid Kubernetes names as they are used to create a VirtualMachine object
+	//   and usually also as the name of the Node object.
+	// * Names are automatically truncated at 63 characters. Please note that this can lead to name conflicts,
+	//   so we highly recommend to use a template which leads to a name shorter than 63 characters.
+	// +optional
+	Template *string `json:"template,omitempty"`
 }
 
 // VSphereMachineStatus defines the observed state of VSphereMachine.

config/default/crd/bases/infrastructure.cluster.x-k8s.io_vspheremachines.yaml

@@ -1026,6 +1026,28 @@ spec:
                   virtual machine is cloned.
                 format: int64
                 type: integer
+              namingStrategy:
+                description: NamingStrategy allows configuring the naming strategy
+                  used when calculating the name of the VirtualMachine.
+                properties:
+                  template:
+                    description: |-
+                      Template defines the template to use for generating the name of the VirtualMachine object.
+                      If not defined, it will fall back to `{{ .machine.name }}`.
+                      The templating has the following data available:
+                      * `.machine.name`: The name of the Machine object.
+                      The templating also has the following funcs available:
+                      * `trimSuffix`: same as strings.TrimSuffix
+                      * `trunc`: truncates a string, e.g. `trunc 2 "hello"` or `trunc -2 "hello"`
+                      Notes:
+                      * While the template offers some flexibility, we would like the name to link to the Machine name
+                        to ensure better user experience when troubleshooting
+                      * Generated names must be valid Kubernetes names as they are used to create a VirtualMachine object
+                        and usually also as the name of the Node object.
+                      * Names are automatically truncated at 63 characters. Please note that this can lead to name conflicts,
+                        so we highly recommend to use a template which leads to a name shorter than 63 characters.
+                    type: string
+                type: object
               network:
                 description: Network is the network configuration for this machine's
                   VM.

config/default/crd/bases/infrastructure.cluster.x-k8s.io_vspheremachinetemplates.yaml

@@ -896,6 +896,28 @@ spec:
                           virtual machine is cloned.
                         format: int64
                         type: integer
+                      namingStrategy:
+                        description: NamingStrategy allows configuring the naming
+                          strategy used when calculating the name of the VirtualMachine.
+                        properties:
+                          template:
+                            description: |-
+                              Template defines the template to use for generating the name of the VirtualMachine object.
+                              If not defined, it will fall back to `{{ .machine.name }}`.
+                              The templating has the following data available:
+                              * `.machine.name`: The name of the Machine object.
+                              The templating also has the following funcs available:
+                              * `trimSuffix`: same as strings.TrimSuffix
+                              * `trunc`: truncates a string, e.g. `trunc 2 "hello"` or `trunc -2 "hello"`
+                              Notes:
+                              * While the template offers some flexibility, we would like the name to link to the Machine name
+                                to ensure better user experience when troubleshooting
+                              * Generated names must be valid Kubernetes names as they are used to create a VirtualMachine object
+                                and usually also as the name of the Node object.
+                              * Names are automatically truncated at 63 characters. Please note that this can lead to name conflicts,
+                                so we highly recommend to use a template which leads to a name shorter than 63 characters.
+                            type: string
+                        type: object
                       network:
                         description: Network is the network configuration for this
                           machine's VM.

pkg/services/vimmachine.go

@@ -18,9 +18,11 @@ limitations under the License.
 package services
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
 	"strings"
+	"text/template"
 
 	"github.com/pkg/errors"
 	corev1 "k8s.io/api/core/v1"
@@ -197,10 +199,15 @@ func (v *VimMachineService) GetHostInfo(ctx context.Context, machineCtx capvcont
 		return "", errors.New("received unexpected VIMMachineContext type")
 	}
 
+	name, err := generateVMObjectName(vimMachineCtx, vimMachineCtx.Machine.Name)
+	if err != nil {
+		return "", err
+	}
+
 	vsphereVM := &infrav1.VSphereVM{}
 	if err := v.Client.Get(ctx, client.ObjectKey{
 		Namespace: vimMachineCtx.VSphereMachine.Namespace,
-		Name:      generateVMObjectName(vimMachineCtx, vimMachineCtx.Machine.Name),
+		Name:      name,
 	}, vsphereVM); err != nil {
 		return "", err
 	}
@@ -215,9 +222,14 @@ func (v *VimMachineService) GetHostInfo(ctx context.Context, machineCtx capvcont
 func (v *VimMachineService) findVSphereVM(ctx context.Context, vimMachineCtx *capvcontext.VIMMachineContext) (*infrav1.VSphereVM, error) {
 	// Get ready to find the associated VSphereVM resource.
 	vm := &infrav1.VSphereVM{}
+	name, err := generateVMObjectName(vimMachineCtx, vimMachineCtx.Machine.Name)
+	if err != nil {
+		return nil, err
+	}
+
 	vmKey := types.NamespacedName{
 		Namespace: vimMachineCtx.VSphereMachine.Namespace,
-		Name:      generateVMObjectName(vimMachineCtx, vimMachineCtx.Machine.Name),
+		Name:      name,
 	}
 	// Attempt to find the associated VSphereVM resource.
 	if err := v.Client.Get(ctx, vmKey, vm); err != nil {
@@ -301,10 +313,15 @@ func (v *VimMachineService) reconcileNetwork(ctx context.Context, vimMachineCtx
 func (v *VimMachineService) createOrPatchVSphereVM(ctx context.Context, vimMachineCtx *capvcontext.VIMMachineContext, vsphereVM *infrav1.VSphereVM) (*infrav1.VSphereVM, error) {
 	log := ctrl.LoggerFrom(ctx)
 	// Create or update the VSphereVM resource.
+	name, err := generateVMObjectName(vimMachineCtx, vimMachineCtx.Machine.Name)
+	if err != nil {
+		return nil, err
+	}
+
 	vm := &infrav1.VSphereVM{
 		ObjectMeta: metav1.ObjectMeta{
 			Namespace: vimMachineCtx.VSphereMachine.Namespace,
-			Name:      generateVMObjectName(vimMachineCtx, vimMachineCtx.Machine.Name),
+			Name:      name,
 		},
 	}
 	mutateFn := func() (err error) {
@@ -393,12 +410,72 @@ func (v *VimMachineService) createOrPatchVSphereVM(ctx context.Context, vimMachi
 
 // generateVMObjectName returns a new VM object name in specific cases, otherwise return the same
 // passed in the parameter.
-func generateVMObjectName(vimMachineCtx *capvcontext.VIMMachineContext, machineName string) string {
+func generateVMObjectName(vimMachineCtx *capvcontext.VIMMachineContext, machineName string) (string, error) {
+	name, err := GenerateVirtualMachineName(machineName, vimMachineCtx.VSphereMachine.Spec.NamingStrategy)
+	if err != nil {
+		return "", err
+	}
 	// Windows VM names must have 15 characters length at max.
 	if vimMachineCtx.VSphereMachine.Spec.OS == infrav1.Windows && len(machineName) > 15 {
-		return strings.TrimSuffix(machineName[0:9], "-") + "-" + machineName[len(machineName)-5:]
+		return strings.TrimSuffix(name[0:9], "-") + "-" + name[len(name)-5:], nil
 	}
-	return machineName
+	return name, nil
+}
+
+const (
+	maxNameLength = 63
+)
+
+// Note: Inlining these functions from sprig to avoid introducing a dependency.
+var nameTemplateFuncs = map[string]any{
+	"trimSuffix": func(a, b string) string { return strings.TrimSuffix(b, a) },
+	"trunc": func(c int, s string) string {
+		if c < 0 && len(s)+c > 0 {
+			return s[len(s)+c:]
+		}
+		if c >= 0 && len(s) > c {
+			return s[:c]
+		}
+		return s
+	},
+}
+
+var nameTpl = template.New("name generator").Funcs(nameTemplateFuncs).Option("missingkey=error")
+
+// GenerateVirtualMachineName generates the name of a VirtualMachine based on the naming strategy.
+func GenerateVirtualMachineName(machineName string, namingStrategy *infrav1.VirtualMachineNamingStrategy) (string, error) {
+	// Per default the name of the VirtualMachine should be equal to the Machine name (this is the same as "{{ .machine.name }}")
+	if namingStrategy == nil || namingStrategy.Template == nil {
+		// Note: No need to trim to max length in this case as valid Machine names will also be valid VirtualMachine names.
+		return machineName, nil
+	}
+
+	nameTemplate := *namingStrategy.Template
+	data := map[string]interface{}{
+		"machine": map[string]interface{}{
+			"name": machineName,
+		},
+	}
+
+	tpl, err := nameTpl.Parse(nameTemplate)
+	if err != nil {
+		return "", errors.Wrapf(err, "failed to generate name for VirtualMachine: failed to parse namingStrategy.template %q", nameTemplate)
+	}
+
+	var buf bytes.Buffer
+	if err := tpl.Execute(&buf, data); err != nil {
+		return "", errors.Wrap(err, "failed to generate name for VirtualMachine")
+	}
+
+	name := buf.String()
+
+	// If the name exceeds the maxNameLength, trim to maxNameLength.
+	// Note: we're not adding a random suffix as the name has to be deterministic.
+	if len(name) > maxNameLength {
+		name = name[:maxNameLength]
+	}
+
+	return name, nil
 }
 
 // generateOverrideFunc returns a function which can override the values in the VSphereVM Spec