feat: support multiple subnets via primarySubnet field

feat: support multiple subnets via primarySubnet field

Handling IP exhaustion

test: include tests for primarySubnet

Use GetNetworkSubnetByParam, add primarySubnet in ValidateUpdate and test cases

Author: memorais

api/v1beta1/openstackcluster_types.go

@@ -54,14 +54,22 @@ type OpenStackClusterSpec struct {
 
 	// Subnets specifies existing subnets to use if not ManagedSubnets are
 	// specified. All subnets must be in the network specified by Network.
-	// There can be zero, one, or two subnets. If no subnets are specified,
-	// all subnets in Network will be used. If 2 subnets are specified, one
-	// must be IPv4 and the other IPv6.
-	// +kubebuilder:validation:MaxItems=2
+	// If no subnets are specified, all subnets in Network will be used.
+	// Multiple subnets of the same IP version are supported when PrimarySubnet
+	// is also set to identify which subnet should be used for services like
+	// load balancer VIP allocation.
 	// +listType=atomic
 	// +optional
 	Subnets []SubnetParam `json:"subnets,omitempty"`
 
+	// PrimarySubnet identifies the primary subnet for the cluster when multiple
+	// subnets are specified in Subnets. It is used to determine the subnet for
+	// load balancer VIP allocation and node member registration.
+	// If not specified and multiple subnets exist, the first subnet in the
+	// resolved Subnets list is used.
+	// +optional
+	PrimarySubnet *SubnetParam `json:"primarySubnet,omitempty"`
+
 	// NetworkMTU sets the maximum transmission unit (MTU) value to address fragmentation for the private network ID.
 	// This value will be used only if the Cluster actuator creates the network.
 	// If left empty, the network will have the default MTU defined in Openstack network service.

api/v1beta1/zz_generated.conversion.go

@@ -43,14 +43,22 @@ type OpenStackClusterSpec struct {
 
 	// subnets specifies existing subnets to use if not ManagedSubnets are
 	// specified. All subnets must be in the network specified by Network.
-	// There can be zero, one, or two subnets. If no subnets are specified,
-	// all subnets in Network will be used. If 2 subnets are specified, one
-	// must be IPv4 and the other IPv6.
-	// +kubebuilder:validation:MaxItems=2
+	// If no subnets are specified, all subnets in Network will be used.
+	// Multiple subnets of the same IP version are supported when primarySubnet
+	// is also set to identify which subnet should be used for services like
+	// load balancer VIP allocation.
 	// +listType=atomic
 	// +optional
 	Subnets []SubnetParam `json:"subnets,omitempty"`
 
+	// primarySubnet identifies the primary subnet for the cluster when multiple
+	// subnets are specified in Subnets. It is used to determine the subnet for
+	// load balancer VIP allocation and node member registration.
+	// If not specified and multiple subnets exist, the first subnet in the
+	// resolved Subnets list is used.
+	// +optional
+	PrimarySubnet *SubnetParam `json:"primarySubnet,omitempty"`
+
 	// managedRouter specifies attributes of the router. The values are used only
 	// if the Cluster actuator creates the router.
 	// +kubebuilder:validation:XValidation:rule="has(self.externalIPs)",message="managedRouter must not be empty if set"