🌱 ClusterClass: add ref and controlPlane name builtin variables

docs/book/src/tasks/experimental-features/cluster-class/write-clusterclass.md

@@ -382,12 +382,18 @@ In addition to variables specified in the ClusterClass, the following builtin va
 referenced in patches:
 - `builtin.cluster.{name,namespace}`
 - `builtin.cluster.topology.{version,class}`
-- `builtin.controlPlane.{replicas,version}`
+- `builtin.controlPlane.{replicas,version,name}`
     - Please note, these variables are only available when patching control plane or control plane 
       machine templates.
+- `builtin.controlPlane.machineTemplate.infrastructureRef.name`
+    - Please note, these variables are only available when using a control plane with machines and 
+      when patching control plane or control plane machine templates.
 - `builtin.machineDeployment.{replicas,version,class,name,topologyName}`
     - Please note, these variables are only available when patching the templates of a MachineDeployment 
       and contain the values of the current `MachineDeployment` topology.
+- `builtin.machineDeployment.{infrastructureRef.name,bootstrap.configRef.name}`
+    - Please note, these variables are only available when patching the templates of a MachineDeployment
+      and contain the values of the current `MachineDeployment` topology.
 
 Builtin variables can be referenced just like regular variables, e.g.:
 ```yaml

docs/proposals/202105256-cluster-class-and-managed-topologies.md

@@ -649,11 +649,17 @@ Note: Builtin variables are defined in [Builtin variables](#builtin-variables) b
 It’s also possible to use so-called builtin variables in addition to user-defined variables. The following builtin variables are available:
 - `builtin.cluster.{name,namespace}`
 - `builtin.cluster.topology.{version,class}`
-- `builtin.controlPlane.{replicas,version}`
+- `builtin.controlPlane.{replicas,version,name}`
     - **Note**: these variables are only available when patching control plane or control plane machine templates.
+- `builtin.controlPlane.machineTemplate.infrastructureRef.name`
+    - **Note**: these variables are only available when using a control plane with machines and
+      when patching control plane or control plane machine templates.
 - `builtin.machineDeployment.{replicas,version,class,name,topologyName}`
     - **Note**: these variables are only available when patching MachineDeployment templates and contain the values 
       of the current `MachineDeploymentTopology`.
+- `builtin.machineDeployment.{infrastructureRef.name,bootstrap.configRef.name}`
+    - **Note**: these variables are only available when patching the templates of a MachineDeployment
+      and contain the values of the current `MachineDeployment` topology.
 
 Builtin variables are available under the `builtin.` prefix. Some examples:
 - Usage of `cluster.name` via variable:

internal/controllers/topology/cluster/patches/engine.go

@@ -138,7 +138,7 @@ func createRequest(blueprint *scope.ClusterBlueprint, desired *scope.ClusterStat
 	req.Items = append(req.Items, t)
 
 	// Calculate controlPlane variables.
-	controlPlaneVariables, err := variables.ControlPlane(&blueprint.Topology.ControlPlane, desired.ControlPlane.Object)
+	controlPlaneVariables, err := variables.ControlPlane(&blueprint.Topology.ControlPlane, desired.ControlPlane.Object, desired.ControlPlane.InfrastructureMachineTemplate)
 	if err != nil {
 		return nil, errors.Wrapf(err, "failed to calculate ControlPlane variables")
 	}
@@ -188,7 +188,7 @@ func createRequest(blueprint *scope.ClusterBlueprint, desired *scope.ClusterStat
 		}
 
 		// Calculate MachineDeployment variables.
-		mdVariables, err := variables.MachineDeployment(mdTopology, md.Object)
+		mdVariables, err := variables.MachineDeployment(mdTopology, md.Object, md.BootstrapTemplate, md.InfrastructureMachineTemplate)
 		if err != nil {
 			return nil, errors.Wrapf(err, "failed to calculate variables for %s", tlog.KObj{Obj: md.Object})
 		}

internal/controllers/topology/cluster/patches/inline/json_patch_generator_test.go

@@ -102,6 +102,14 @@ func TestGenerate(t *testing.T) {
 									Variable: pointer.String("builtin.controlPlane.replicas"),
 								},
 							},
+							// test .builtin.controlPlane.machineTemplate.InfrastructureRef.name var.
+							{
+								Op:   "replace",
+								Path: "/spec/template/spec/files",
+								ValueFrom: &clusterv1.JSONPatchValue{
+									Template: pointer.String(`[{"contentFrom":{"secret":{"key":"control-plane-azure.json","name":"{{ .builtin.controlPlane.machineTemplate.infrastructureRef.name }}-azure-json"}}}]`),
+								},
+							},
 						},
 					},
 				},
@@ -121,7 +129,7 @@ func TestGenerate(t *testing.T) {
 							TemplateType: api.ControlPlaneTemplateType,
 						},
 						Variables: map[string]apiextensionsv1.JSON{
-							"builtin":   {Raw: []byte(`{"controlPlane":{"replicas":3}}`)},
+							"builtin":   {Raw: []byte(`{"controlPlane":{"replicas":3,"machineTemplate":{"infrastructureRef":{"name":"controlPlaneInfrastructureMachineTemplate1"}}}}`)},
 							"variableC": {Raw: []byte(`"C-template"`)},
 						},
 					},
@@ -141,8 +149,15 @@ func TestGenerate(t *testing.T) {
 {"op":"replace","path":"/spec/valueFrom/template","value":"template bbbbb"},
 {"op":"replace","path":"/spec/templatePrecedent","value":"C-template"},
 {"op":"replace","path":"/spec/builtinClusterName","value":"cluster-name"},
-{"op":"replace","path":"/spec/builtinControlPlaneReplicas","value":3}
-]`),
+{"op":"replace","path":"/spec/builtinControlPlaneReplicas","value":3},
+{"op":"replace","path":"/spec/template/spec/files","value":[{
+  "contentFrom":{
+    "secret":{
+      "key":"control-plane-azure.json",
+      "name":"controlPlaneInfrastructureMachineTemplate1-azure-json"
+    }
+  }
+}]}]`),
 						PatchType: api.JSONPatchType,
 					},
 				},

internal/controllers/topology/cluster/patches/variables/variables.go

@@ -73,8 +73,28 @@ type ControlPlaneBuiltins struct {
 	// being orchestrated.
 	Version string `json:"version,omitempty"`
 
+	// Name is the name of the ControlPlane,
+	// to which the current template belongs to.
+	Name string `json:"name,omitempty"`
+
 	// Replicas is the value of the replicas field of the ControlPlane object.
 	Replicas *int64 `json:"replicas,omitempty"`
+
+	// MachineTemplate is the value of the .spec.machineTemplate field of the ControlPlane object.
+	MachineTemplate *ControlPlaneMachineTemplateBuiltins `json:"machineTemplate,omitempty"`
+}
+
+// ControlPlaneMachineTemplateBuiltins is the value of the .spec.machineTemplate field of the ControlPlane object.
+type ControlPlaneMachineTemplateBuiltins struct {
+	// InfrastructureRef is the value of the infrastructureRef field of ControlPlane.spec.machineTemplate.
+	InfrastructureRef ControlPlaneMachineTemplateInfrastructureRefBuiltins `json:"infrastructureRef,omitempty"`
+}
+
+// ControlPlaneMachineTemplateInfrastructureRefBuiltins is the value of the infrastructureRef field of
+// ControlPlane.spec.machineTemplate.
+type ControlPlaneMachineTemplateInfrastructureRefBuiltins struct {
+	// Name of the infrastructureRef.
+	Name string `json:"name,omitempty"`
 }
 
 // MachineDeploymentBuiltins represents builtin MachineDeployment variables.
@@ -102,6 +122,33 @@ type MachineDeploymentBuiltins struct {
 	// Replicas is the value of the replicas field of the MachineDeployment,
 	// to which the current template belongs to.
 	Replicas *int64 `json:"replicas,omitempty"`
+
+	// Bootstrap is the value of the .spec.template.spec.bootstrap field of the MachineDeployment.
+	Bootstrap *MachineDeploymentBootstrapBuiltins `json:"bootstrap,omitempty"`
+
+	// InfrastructureRef is the value of the .spec.template.spec.bootstrap field of the MachineDeployment.
+	InfrastructureRef *MachineDeploymentInfrastructureRefBuiltins `json:"infrastructureRef,omitempty"`
+}
+
+// MachineDeploymentBootstrapBuiltins is the value of the .spec.template.spec.bootstrap field
+// of the MachineDeployment.
+type MachineDeploymentBootstrapBuiltins struct {
+	// ConfigRef is the value of the .spec.template.spec.bootstrap.configRef field of the MachineDeployment.
+	ConfigRef *MachineDeploymentBootstrapConfigRefBuiltins `json:"configRef,omitempty"`
+}
+
+// MachineDeploymentBootstrapConfigRefBuiltins is the value of the .spec.template.spec.bootstrap.configRef
+// field of the MachineDeployment.
+type MachineDeploymentBootstrapConfigRefBuiltins struct {
+	// Name of the bootstrap.configRef.
+	Name string `json:"name,omitempty"`
+}
+
+// MachineDeploymentInfrastructureRefBuiltins is the value of the .spec.template.spec.infrastructureRef field
+// of the MachineDeployment.
+type MachineDeploymentInfrastructureRefBuiltins struct {
+	// Name of the infrastructureRef.
+	Name string `json:"name,omitempty"`
 }
 
 // VariableMap is a name/value map of variables.
@@ -139,32 +186,42 @@ func Global(clusterTopology *clusterv1.Topology, cluster *clusterv1.Cluster) (Va
 }
 
 // ControlPlane returns variables that apply to templates belonging to the ControlPlane.
-func ControlPlane(controlPlaneTopology *clusterv1.ControlPlaneTopology, controlPlane *unstructured.Unstructured) (VariableMap, error) {
+func ControlPlane(cpTopology *clusterv1.ControlPlaneTopology, cp, cpInfrastructureMachineTemplate *unstructured.Unstructured) (VariableMap, error) {
 	variables := VariableMap{}
 
 	// Construct builtin variable.
 	builtin := Builtins{
-		ControlPlane: &ControlPlaneBuiltins{},
+		ControlPlane: &ControlPlaneBuiltins{
+			Name: cp.GetName(),
+		},
 	}
 
 	// If it is required to manage the number of replicas for the ControlPlane, set the corresponding variable.
 	// NOTE: If the Cluster.spec.topology.controlPlane.replicas field is nil, the topology reconciler won't set
 	// the replicas field on the ControlPlane. This happens either when the ControlPlane provider does
 	// not implement support for this field or the default value of the ControlPlane is used.
-	if controlPlaneTopology.Replicas != nil {
-		replicas, err := contract.ControlPlane().Replicas().Get(controlPlane)
+	if cpTopology.Replicas != nil {
+		replicas, err := contract.ControlPlane().Replicas().Get(cp)
 		if err != nil {
 			return nil, errors.Wrap(err, "failed to get spec.replicas from the ControlPlane")
 		}
 		builtin.ControlPlane.Replicas = replicas
 	}
 
-	version, err := contract.ControlPlane().Version().Get(controlPlane)
+	version, err := contract.ControlPlane().Version().Get(cp)
 	if err != nil {
 		return nil, errors.Wrap(err, "failed to get spec.version from the ControlPlane")
 	}
 	builtin.ControlPlane.Version = *version
 
+	if cpInfrastructureMachineTemplate != nil {
+		builtin.ControlPlane.MachineTemplate = &ControlPlaneMachineTemplateBuiltins{
+			InfrastructureRef: ControlPlaneMachineTemplateInfrastructureRefBuiltins{
+				Name: cpInfrastructureMachineTemplate.GetName(),
+			},
+		}
+	}
+
 	if err := setVariable(variables, BuiltinsName, builtin); err != nil {
 		return nil, err
 	}
@@ -173,7 +230,7 @@ func ControlPlane(controlPlaneTopology *clusterv1.ControlPlaneTopology, controlP
 }
 
 // MachineDeployment returns variables that apply to templates belonging to a MachineDeployment.
-func MachineDeployment(mdTopology *clusterv1.MachineDeploymentTopology, md *clusterv1.MachineDeployment) (VariableMap, error) {
+func MachineDeployment(mdTopology *clusterv1.MachineDeploymentTopology, md *clusterv1.MachineDeployment, mdBootstrapTemplate, mdInfrastructureMachineTemplate *unstructured.Unstructured) (VariableMap, error) {
 	variables := VariableMap{}
 
 	// Add variables overrides for the MachineDeployment.
@@ -196,6 +253,20 @@ func MachineDeployment(mdTopology *clusterv1.MachineDeploymentTopology, md *clus
 		builtin.MachineDeployment.Replicas = pointer.Int64(int64(*md.Spec.Replicas))
 	}
 
+	if mdBootstrapTemplate != nil {
+		builtin.MachineDeployment.Bootstrap = &MachineDeploymentBootstrapBuiltins{
+			ConfigRef: &MachineDeploymentBootstrapConfigRefBuiltins{
+				Name: mdBootstrapTemplate.GetName(),
+			},
+		}
+	}
+
+	if mdInfrastructureMachineTemplate != nil {
+		builtin.MachineDeployment.InfrastructureRef = &MachineDeploymentInfrastructureRefBuiltins{
+			Name: mdInfrastructureMachineTemplate.GetName(),
+		}
+	}
+
 	if err := setVariable(variables, BuiltinsName, builtin); err != nil {
 		return nil, err
 	}