feat: add support for disabling pod IP cidr overprovision

This feature requires special allowlisting for the projects.

PiperOrigin-RevId: 522103451

google/container/v1/cluster_service.proto

@@ -891,6 +891,20 @@ message NodeNetworkConfig {
 
   // Network bandwidth tier configuration.
   optional NetworkPerformanceConfig network_performance_config = 11;
+
+  // [PRIVATE FIELD]
+  // Pod CIDR size overprovisioning config for the nodepool.
+  //
+  // Pod CIDR size per node depends on max_pods_per_node. By default, the value
+  // of max_pods_per_node is rounded off to next power of 2 and we then double
+  // that to get the size of pod CIDR block per node.
+  // Example: max_pods_per_node of 30 would result in 64 IPs (/26).
+  //
+  // This config can disable the doubling of IPs (we still round off to next
+  // power of 2)
+  // Example: max_pods_per_node of 30 will result in 32 IPs (/27) when
+  // overprovisioning is disabled.
+  PodCIDROverprovisionConfig pod_cidr_overprovision_config = 13;
 }
 
 // A set of Shielded Instance options.
@@ -1334,6 +1348,14 @@ message BinaryAuthorization {
   EvaluationMode evaluation_mode = 2;
 }
 
+// [PRIVATE FIELD]
+// Config for pod CIDR size overprovisioning.
+message PodCIDROverprovisionConfig {
+  // Whether Pod CIDR overprovisioning is disabled.
+  // Note: Pod CIDR overprovisioning is enabled by default.
+  bool disable = 1;
+}
+
 // Configuration for controlling how IPs are allocated in the cluster.
 message IPAllocationPolicy {
   // Whether alias IPs will be used for pod IPs in the cluster.
@@ -1458,6 +1480,20 @@ message IPAllocationPolicy {
   // The ipv6 access type (internal or external) when create_subnetwork is true
   IPv6AccessType ipv6_access_type = 17;
 
+  // [PRIVATE FIELD]
+  // Pod CIDR size overprovisioning config for the cluster.
+  //
+  // Pod CIDR size per node depends on max_pods_per_node. By default, the value
+  // of max_pods_per_node is doubled and then rounded off to next power of 2 to
+  // get the size of pod CIDR block per node.
+  // Example: max_pods_per_node of 30 would result in 64 IPs (/26).
+  //
+  // This config can disable the doubling of IPs (we still round off to next
+  // power of 2)
+  // Example: max_pods_per_node of 30 will result in 32 IPs (/27) when
+  // overprovisioning is disabled.
+  PodCIDROverprovisionConfig pod_cidr_overprovision_config = 21;
+
   // Output only. [Output only] The subnet's IPv6 CIDR block used by nodes and
   // pods.
   string subnet_ipv6_cidr_block = 22