Is it supported to use gateway-mode-config to set OVN-Kubernetes gateway mode in RHOCP 4.10 and higher?

Solution Verified - Updated

Environment

  • Red Hat OpenShift Container Platform
    • 4.10 and higher

Issue

Resolution

Starting 4.10, it is no longer supported to use the gateway-mode-config configmap to configure local gateway mode in OVN Kubernetes in the way documented in 4.8 release notes.

During the upgrade of 4.10, if gateway-mode-config configmap is present, the spec.defaultNetwork.ovnKubernetesConfig.gatewayConfig.routingViaHost field of the network.operator.openshift.io/cluster object is populated to match it. After that, the configmap is ignored, and it should be removed.
On OCP 4.10+ you can configured by following the official documentation here in the "Configuration for the OVN-Kubernetes CNI cluster network provider" section.

So, if the cluster is in 4.10 or higher and the configmap is still present (check "diagnostic steps" section), it should be removed like this:

$ oc -n openshift-network-operator delete cm gateway-mode-config
configmap "gateway-mode-config" deleted

Root Cause

When shared gateway was made default in 4.8, the gateway-mode-config configmap was introduced as a workaround to keep local gateway for those who require it.

However, this is not a consistent way to configure such a setting, so in 4.10, a proper setting was introduced in the network.operator.openshift.io custom resource to perform this configuration via API.

Diagnostic Steps

  • Check that RHOCP cluster version is 4.10 or higher

     $ oc get clusterversion
NAME      VERSION   AVAILABLE   PROGRESSING   SINCE   STATUS
version   4.10.56   True        False         22h     Cluster version is 4.10.56

  • Check if the gateway-mode-config configmap exist

     $ oc -n openshift-network-operator get cm/gateway-mode-config
 NAME                  DATA   AGE
 gateway-mode-config   1      16d
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