OCPBUGS-61876: Provide a MinPortsPerVM for Nat Router

** This is a regression for the openshift installer.

Instead of filling this value in, the default will be 64 (so that this is backwards compatible), otherwise
the user can provide this information in the cluster spec.

** MinPortsPerVM: Minimum number of ports allocated to a VM from this NAT
config. If not set, a default number of ports is allocated to a VM. This is
rounded up to the nearest power of 2. For example, if the value of this
field is 50, at least 64 ports are allocated to a VM.

Author: barbacbd

api/v1beta1/types.go

@@ -147,6 +147,16 @@ type NetworkSpec struct {
 	// +kubebuilder:default:=1460
 	// +optional
 	Mtu int64 `json:"mtu,omitempty"`
+
+	// MinPortsPerVM: Minimum number of ports allocated to a VM from this NAT
+	// config. If not set, a default number of ports is allocated to a VM. This is
+	// rounded up to the nearest power of 2. For example, if the value of this
+	// field is 50, at least 64 ports are allocated to a VM.
+	// +kubebuilder:validation:Minimum:=2
+	// +kubebuilder:validation:Maximum:=65536
+	// +kubebuilder:default:=64
+	// +optional
+	MinPortsPerVM int64 `json:"minPortsPerVm,omitempty"`
 }
 
 // LoadBalancerType defines the Load Balancer that should be created.

cloud/scope/cluster.go

@@ -237,6 +237,7 @@ func (s *ClusterScope) NatRouterSpec() *compute.Router {
 				Name:                          fmt.Sprintf("%s-%s", networkSpec.Name, "nat"),
 				NatIpAllocateOption:           "AUTO_ONLY",
 				SourceSubnetworkIpRangesToNat: "ALL_SUBNETWORKS_ALL_IP_RANGES",
+				MinPortsPerVm:                 s.GCPCluster.Spec.Network.MinPortsPerVM,
 			},
 		},
 	}

cloud/scope/managedcluster.go

@@ -221,6 +221,7 @@ func (s *ManagedClusterScope) NatRouterSpec() *compute.Router {
 				Name:                          fmt.Sprintf("%s-%s", networkSpec.Name, "nat"),
 				NatIpAllocateOption:           "AUTO_ONLY",
 				SourceSubnetworkIpRangesToNat: "ALL_SUBNETWORKS_ALL_IP_RANGES",
+				MinPortsPerVm:                 s.GCPManagedCluster.Spec.Network.MinPortsPerVM,
 			},
 		},
 	}

config/crd/bases/infrastructure.cluster.x-k8s.io_gcpclusters.yaml

@@ -188,6 +188,17 @@ spec:
                       (useful for changing apiserver port)
                     format: int32
                     type: integer
+                  minPortsPerVm:
+                    default: 64
+                    description: |-
+                      MinPortsPerVM: Minimum number of ports allocated to a VM from this NAT
+                      config. If not set, a default number of ports is allocated to a VM. This is
+                      rounded up to the nearest power of 2. For example, if the value of this
+                      field is 50, at least 64 ports are allocated to a VM.
+                    format: int64
+                    maximum: 65536
+                    minimum: 2
+                    type: integer
                   mtu:
                     default: 1460
                     description: |-

config/crd/bases/infrastructure.cluster.x-k8s.io_gcpclustertemplates.yaml

@@ -207,6 +207,17 @@ spec:
                               backend (useful for changing apiserver port)
                             format: int32
                             type: integer
+                          minPortsPerVm:
+                            default: 64
+                            description: |-
+                              MinPortsPerVM: Minimum number of ports allocated to a VM from this NAT
+                              config. If not set, a default number of ports is allocated to a VM. This is
+                              rounded up to the nearest power of 2. For example, if the value of this
+                              field is 50, at least 64 ports are allocated to a VM.
+                            format: int64
+                            maximum: 65536
+                            minimum: 2
+                            type: integer
                           mtu:
                             default: 1460
                             description: |-

config/crd/bases/infrastructure.cluster.x-k8s.io_gcpmanagedclusters.yaml

@@ -184,6 +184,17 @@ spec:
                       (useful for changing apiserver port)
                     format: int32
                     type: integer
+                  minPortsPerVm:
+                    default: 64
+                    description: |-
+                      MinPortsPerVM: Minimum number of ports allocated to a VM from this NAT
+                      config. If not set, a default number of ports is allocated to a VM. This is
+                      rounded up to the nearest power of 2. For example, if the value of this
+                      field is 50, at least 64 ports are allocated to a VM.
+                    format: int64
+                    maximum: 65536
+                    minimum: 2
+                    type: integer
                   mtu:
                     default: 1460
                     description: |-

config/crd/bases/infrastructure.cluster.x-k8s.io_gcpmanagedclustertemplates.yaml

@@ -178,6 +178,17 @@ spec:
                               backend (useful for changing apiserver port)
                             format: int32
                             type: integer
+                          minPortsPerVm:
+                            default: 64
+                            description: |-
+                              MinPortsPerVM: Minimum number of ports allocated to a VM from this NAT
+                              config. If not set, a default number of ports is allocated to a VM. This is
+                              rounded up to the nearest power of 2. For example, if the value of this
+                              field is 50, at least 64 ports are allocated to a VM.
+                            format: int64
+                            maximum: 65536
+                            minimum: 2
+                            type: integer
                           mtu:
                             default: 1460
                             description: |-