Manage subnets for workloads

Based on the number of workloads you're running in your organization, you might need to create additional node subnets to support your workloads' networking requirements. For example, if you have a large number of VM workloads, and those workloads require additional IP addresses in a subnet, then you must create additional node subnets.

Create more subnets in default VPC

During the creation of an organization, a default node subnet in the default Virtual Private Cloud (VPC) is created automatically in the platform namespace of the organization. The default node subnet is used to allocate IP addresses for cluster nodes inside the organization, as well as virtual machine (VM) workloads.

Create more node subnets in the default VPC to allocate additional IP addresses for your workloads.

1. Create a YAML file, such as subnet.yaml, for your new node subnet:

   apiVersion: ipam.gdc.goog/v1
   kind: Subnet
   metadata:
     labels:
       ipam.gdc.goog/vpc: default-vpc  # Must set this value to default-vpc to indicate the subnet is in the default VPC.
     name: SUBNET_NAME
     namespace: platform  # Namespace for all node subnets in the default VPC is platform.
   spec:
     ipv4Request:
       prefixLength: CIDR_PREFIX_LENGTH
     networkSpec:
       enableGateway: true  # Reserves a gateway IP address for the subnet.
     parentReference:
       name: PARENT_SUBNET_NAME
       namespace: platform
     type: Branch
   

   Replace the following:

   • SUBNET_NAME: the name of your new node subnet.

   • CIDR_PREFIX_LENGTH: the CIDR prefix length of your new node subnet.

   • PARENT_SUBNET_NAME: the name of the parent subnet, such as default-vpc-zone0-cidr. The parent subnet is typically a zonal root subnet in the default VPC.

   See the API reference documentation for the Subnet resource for more information.

2. Apply the new node subnet to your organization:

   kubectl apply -f subnet.yaml --kubeconfig MANAGEMENT_API_SERVER_KUBECONFIG
   

   Replace MANAGEMENT_API_SERVER_KUBECONFIG with the path to the kubeconfig file of your Management API server.

Upscale subnets

The Subnet resource doesn't support upscaling automatically. To add more CIDR range to a VPC or network segment, your Infrastructure Operator (IO) must create new subnets with certain labels. Make a request to your IO to add the appropriate labels to new subnets to enable upscaling.