Often times, it is useful to be able to apply custom external_ids settings to running ovn-controller. These may control different aspects of OVN / OVS behavior, e.g. timeouts or new features. It's not always known in advance which of these OVN / OVS features would be useful for a particular deployment. Once we find out a knob may be helpful, there is no way to configure it for Data plane nodes.

At the moment, OVN operator supports specifying custom external-ids for OVNController CR. On the other hand, edpm-ansible ovn role does not support appending custom external-ids.

Note: Interestingly, ovn-operator does not support other_config configuration; but edpm-ansible has a separate variable for this dictionary: edpm_ovn_ovs_other_config. This dictionary is also sometimes used by OVS / OVN to carry configuration. Maybe we should expose it in ovn-operator too to keep symmetry with edpm-ansible.