GKE - network is not ready: Kubenet does not have netConfig

This means that you choose a CIDR with less IPs than you need, when we deploy a cluster on Kubernetes be on Google Cloud or Baremetal we define a range of CIDR, you should commonly use a /16 CIDR like 10.50.0.0/16 this will give you options to use more than 65K ips internally, please remember that on Kubernetes you have IPs not only for pods but for services and other things as well, never choose less than /24 (~250 IPs) unless you will deploy a real little cluster.