Fix failure domains

api/v1alpha4/conversion.go

@@ -139,8 +139,6 @@ func (src *ClusterClass) ConvertTo(dstRaw conversion.Hub) error {
 		dst.Spec.Workers.MachineDeployments[i].Strategy = restored.Spec.Workers.MachineDeployments[i].Strategy
 	}
 
-	dst.Spec.Workers.MachinePools = restored.Spec.Workers.MachinePools
-
 	dst.Status = restored.Status
 
 	return nil

api/v1beta1/cluster_types.go

@@ -263,10 +263,10 @@ type MachinePoolTopology struct {
 	// the values are hashed together.
 	Name string `json:"name"`
 
-	// FailureDomain is the failure domain the machine pools will be created in.
-	// Must match a key in the FailureDomain map stored on the cluster object.
+	// FailureDomains is the list of failure domains the machine pool will be created in.
+	// Must match a key in the FailureDomains map stored on the cluster object.
 	// +optional
-	FailureDomain *string `json:"failureDomain,omitempty"`
+	FailureDomains []string `json:"failureDomains,omitempty"`
 
 	// NodeDrainTimeout is the total amount of time that the controller will spend on draining a node.
 	// The default value is 0, meaning that the node can be drained without any time limitations.

api/v1beta1/clusterclass_types.go

@@ -157,7 +157,7 @@ type MachineDeploymentClass struct {
 	MachineHealthCheck *MachineHealthCheckClass `json:"machineHealthCheck,omitempty"`
 
 	// FailureDomain is the failure domain the machines will be created in.
-	// Must match a key in the FailureDomain map stored on the cluster object.
+	// Must match a key in the FailureDomains map stored on the cluster object.
 	// NOTE: This value can be overridden while defining a Cluster.Topology using this MachineDeploymentClass.
 	// +optional
 	FailureDomain *string `json:"failureDomain,omitempty"`
@@ -261,11 +261,11 @@ type MachinePoolClass struct {
 	// MachinePools objects representing a pool of worker nodes.
 	Template MachinePoolClassTemplate `json:"template"`
 
-	// FailureDomain is the failure domain the machine pools will be created in.
-	// Must match a key in the FailureDomain map stored on the cluster object.
+	// FailureDomains is the list of failure domains the MachinePool should be attached to.
+	// Must match a key in the FailureDomains map stored on the cluster object.
 	// NOTE: This value can be overridden while defining a Cluster.Topology using this MachinePoolClass.
 	// +optional
-	FailureDomain *string `json:"failureDomain,omitempty"`
+	FailureDomains []string `json:"failureDomains,omitempty"`
 
 	// NodeDrainTimeout is the total amount of time that the controller will spend on draining a node.
 	// The default value is 0, meaning that the node can be drained without any time limitations.

api/v1beta1/condition_consts.go

@@ -305,6 +305,7 @@ const (
 
 	// TopologyReconciledMachinePoolsCreatePendingReason (Severity=Info) documents reconciliation of a Cluster topology
 	// not yet completed because at least one of the MachinePools is yet to be created.
+	// This generally happens because new MachinePool creations are held off while the ControlPlane is not stable.
 	TopologyReconciledMachinePoolsCreatePendingReason = "MachinePoolsCreatePending"
 
 	// TopologyReconciledMachinePoolsUpgradeDeferredReason (Severity=Info) documents reconciliation of a Cluster topology

internal/controllers/topology/cluster/desired_state.go

@@ -975,9 +975,9 @@ func computeMachinePool(_ context.Context, s *scope.Scope, desiredControlPlaneSt
 	version := computeMachinePoolVersion(s, desiredControlPlaneState, machinePoolTopology, currentMachinePool)
 
 	// Compute values that can be set both in the MachinePoolClass and in the MachinePoolTopology
-	failureDomain := machinePoolClass.FailureDomain
-	if machinePoolTopology.FailureDomain != nil {
-		failureDomain = machinePoolTopology.FailureDomain
+	failureDomains := machinePoolClass.FailureDomains
+	if machinePoolTopology.FailureDomains != nil {
+		failureDomains = machinePoolTopology.FailureDomains
 	}
 
 	nodeDrainTimeout := machinePoolClass.NodeDrainTimeout
@@ -1015,15 +1015,14 @@ func computeMachinePool(_ context.Context, s *scope.Scope, desiredControlPlaneSt
 			Namespace: s.Current.Cluster.Namespace,
 		},
 		Spec: expv1.MachinePoolSpec{
-			ClusterName: s.Current.Cluster.Name,
-			//Replicas: ,
+			ClusterName:    s.Current.Cluster.Name,
+			FailureDomains: failureDomains,
 			Template: clusterv1.MachineTemplateSpec{
 				Spec: clusterv1.MachineSpec{
 					ClusterName:             s.Current.Cluster.Name,
 					Version:                 pointer.String(version),
 					Bootstrap:               clusterv1.Bootstrap{ConfigRef: desiredBootstrapTemplateRef},
 					InfrastructureRef:       *desiredInfraMachineTemplateRef,
-					FailureDomain:           failureDomain,
 					NodeDrainTimeout:        nodeDrainTimeout,
 					NodeVolumeDetachTimeout: nodeVolumeDetachTimeout,
 					NodeDeletionTimeout:     nodeDeletionTimeout,