PodCIDR is Missing From The Node Spec of PMK Cluster

Problem

• The Citrix ingress controller uses a feature called feature-node-watch to automatically configure route on the associated load balancer by reading the podCIDR information from the node spec.
• This feature does not work with the PMK cluster as it does not have podCIDR information included in node spec. This feature works fine with vanilla Kubernetes.

Environment

• Platform9 Managed Kubernetes - v4.0 and Higher
• Citrix Ingress Controller

Cause

• In Vanilla Kubernetes Flannel is deployed with the flag --kube-subnet-mgr. This flag specifies that Flannel should contact Kubernetes API for subnet configuration on the node. For this reason, nodes resources are created with podCIDR in their spec.
• In PMK, Flannel is configured to get the subnet configuration from etcd. The PMK cluster Flannel CNI is brought up before Kubernetes control plane pods. Also, the flannel container runs outside of k8s and so it does not have an API server to talk to at the time of its bootstrap.

Resolution

1. This is by design, we have created a feature request PMK8-I-138 to have the podCIDR information included in the node spec of the PMK clusters.
2. You can upvote this feature request by logging in to our Ideas portal.