Resolve IP range conflicts with K8s installations

Updated: February 2025

Audience: Everyone

Environmental details: Self-hosted - KOTS channels

Summary

There may be IP subnet conflicts where the self-hosted machine uses the same IP range as KOTS.

The following patch YAML can be used to configure the IP address ranges of Pods and Services.

Note that the installer will attempt to default to 10.32.0.0/20 for Pods and 10.96.0.0/22 for Services.

If unavailable, the installer will attempt to find an available range with prefix bits of 20 and 22, respectively, in the 10.32.0.0/16 or 10.0.0.0/8 address spaces.

apiVersion: cluster.kurl.sh/v1beta1
  kind: Installer
  metadata:
    name: "patch"
  spec:
    kubernetes:
      serviceCIDR: "<your custom subnet>"
    flannel:     
      podCIDR: "<your custom subnet>"

Save the above as a .yaml file (note being a yaml file, the indentation is mandatory), and run the install as follows:

curl -sSL https://k8s.kurl.sh/jama-k8s-standardkots | sudo bash -s installer-spec-file=[path to YAML patch]Further Details on the above process can be found here:

https://kurl.sh/docs/install-with-kurl#select-examples-of-using-a-patch-yaml-file

Flannel specifics can be found here:

https://kurl.sh/docs/add-ons/flannel#custom-pod-subnet