CKS - option to define Calico ippool during deployment

[chunkyen]

Hi, I am trying out CKS using the pre-built calico iso on 4.21. It deploys fine but I soon found out that LB backed svc external IP are stucked at pending state. On further troubleshooting, LB was not created on the guest network where the CKS sits on, and it is due to cloud-controller-manager not able to talk to Cloudstack API endpoint.

This is due to an IP CIDR range overlap between the calico default pod CIDR (192.168.0.0/16) and my public network. I can change this easily by editing the ippool crd to a different range and then restarting all the pods using the old range. Once they are restarted, they will get the new range and external comm will work correctly.

However, I was wondering is there a way for me to specify the pod cidr during CKS creation. I felt it is possible using the CNI configuration however I have trouble trying to configure the CNI config correctly as docuemntation and examples are extremely limited in this area.
Can someone give me some pointers on how I can write the CNI config? Thanks