handle nil cluster network & SG precedence, add TerminalError

Signed-off-by: Bharath Nallapeta <[email protected]>

addressed PR comments on secGroups

Signed-off-by: Bharath Nallapeta <[email protected]>

Author: bnallapeta

controllers/openstackmachine_controller.go

@@ -522,7 +522,8 @@ func openStackMachineSpecToOpenStackServerSpec(openStackMachineSpec *infrav1.Ope
 		serverPorts = make([]infrav1.PortOpts, 1)
 	}
 	for i := range serverPorts {
-		if serverPorts[i].Network == nil {
+		// Only inject the default network when we actually have an ID.
+		if serverPorts[i].Network == nil && defaultNetworkID != "" {
 			serverPorts[i].Network = &infrav1.NetworkParam{
 				ID: &defaultNetworkID,
 			}
@@ -589,7 +590,18 @@ func (r *OpenStackMachineReconciler) getOrCreateMachineServer(ctx context.Contex
 			}
 			return openStackCluster.Spec.IdentityRef
 		}()
-		machineServerSpec := openStackMachineSpecToOpenStackServerSpec(&openStackMachine.Spec, identityRef, compute.InstanceTags(&openStackMachine.Spec, openStackCluster), failureDomain, userDataRef, getManagedSecurityGroup(openStackCluster, machine), openStackCluster.Status.Network.ID)
+			// Determine default network ID if the cluster status exposes one.
+		var defaultNetworkID string
+		if openStackCluster.Status.Network != nil {
+			defaultNetworkID = openStackCluster.Status.Network.ID
+		}
+
+		// If no cluster network is available AND the machine spec did not define any ports with a network, we cannot choose a network.
+		if defaultNetworkID == "" && len(openStackMachine.Spec.Ports) == 0 {
+			return nil, capoerrors.Terminal(infrav1.InvalidMachineSpecReason, "no network configured: cluster network is missing and machine spec does not define ports with a network")
+		}
+
+		machineServerSpec := openStackMachineSpecToOpenStackServerSpec(&openStackMachine.Spec, identityRef, compute.InstanceTags(&openStackMachine.Spec, openStackCluster), failureDomain, userDataRef, getManagedSecurityGroup(openStackCluster, machine), defaultNetworkID)
 		machineServer = &infrav1alpha1.OpenStackServer{
 			ObjectMeta: metav1.ObjectMeta{
 				Labels: map[string]string{