Create external subnets for Cloud NAT

Create external subnets

To specify what egress IP addresses the gateway can use, you create external leaf subnets containing those IP addresses. The subnets to be used in a Cloud NAT gateway are required to be of the leaf type, as described in Subnet hierarchy, and must be in the same project as the gateway. These subnets must be derived from external subnets (subnets that contain external IP addresses).

For example:

apiVersion: ipam.gdc.goog/v1
kind: Subnet
metadata:
  name: external-zone1-root
  namespace: project-1
spec:
  ipv4Request:
    cidr: 203.0.113.0/24
  type: Root
---
apiVersion: ipam.gdc.goog/v1
kind: Subnet
metadata:
  name: subnet-1
  namespace: project-1
spec:
  ipv4Request:
    cidr: 203.0.113.1/32
  type: Leaf
  parentReference:
    Name: external-zone1-root
    Namespace: project-1
---
apiVersion: ipam.gdc.goog/v1
kind: Subnet
metadata:
  name: subnet-2
  namespace: project-1
spec:
  ipv4Request:
    prefixLength: 30
  type: Leaf
  parentReference:
    Name: external-zone1-root
    Namespace: project-1