We recently got queries about Submariner support in Red Hat OpenShift on IBM Cloud (ROKS) clusters which use Calico CNI (see https://bugzilla.redhat.com/show_bug.cgi?id=2165105). While Submariner can be made to work with Calico (https://submariner.io/operations/deployment/calico/), this seems to be true for Calico with VXLAN mode and not IPIP which is what IBM Cloud is using.

The goal for this spike is for us to better understand what are the gaps or extra configurations required to make Submariner work with Calico with IPIP, as configured in the IBM Cloud environment. We hope we can get access to a couple of (non-production) ROKS clusters we can use for testing and experimentation.

Key contact person on IBM: Cale Rath (ctrath@us.ibm.com) - lead network architect for IBM Cloud.

Note: we need to be clear that we are not offering any kind of support for Submariner in the context of IBM Cloud at this time. This spike is really for us to understand where we stand.