CRD-Backed by Cilium Cluster-Pool IPAM

This is a quick tutorial walking through how to enable CRD-backed by Cilium cluster-pool IPAM. The purpose of this tutorial is to show how components are configured and resources interact with each other to enable users to automate or extend on their own.

For more details, see the section Cluster Scope (Default)

Enable Cluster-pool IPAM mode

Setup Cilium for Kubernetes using helm with the options: --set ipam.mode=cluster-pool.
Depending if you are using IPv4 and / or IPv6, you might want to adjust the podCIDR allocated for your cluster’s pods with the options:
- --set ipam.operator.clusterPoolIPv4PodCIDRList=<IPv4CIDR>
- --set ipam.operator.clusterPoolIPv6PodCIDRList=<IPv6CIDR>
To adjust the CIDR size that should be allocated for each node you can use the following options:
- --set ipam.operator.clusterPoolIPv4MaskSize=<IPv4MaskSize>
- --set ipam.operator.clusterPoolIPv6MaskSize=<IPv6MaskSize>
Deploy Cilium and Cilium-Operator. Cilium will automatically wait until the podCIDR is allocated for its node by Cilium Operator.

Validate installation

Validate that Cilium has started up correctly

$ cilium-dbg status --all-addresses
KVStore:                Ok   etcd: 1/1 connected, has-quorum=true: https://192.168.60.11:2379 - 3.3.12 (Leader)
[...]
IPAM:                   IPv4: 2/256 allocated,
Allocated addresses:
  10.0.0.1 (router)
  10.0.0.3 (health)

Validate the spec.ipam.podCIDRs section:

$ kubectl get cn k8s1 -o yaml
apiVersion: cilium.io/v2
kind: CiliumNode
metadata:
  name: k8s1
  [...]
spec:
  ipam:
    podCIDRs:
      - 10.0.0.0/24