With OCP 4.17, a new command is added to add worker nodes to a cluster. It needs nodes-config.yaml to be specified along with the host mac addreess when creating a nodes.iso. 

However,in reality the host mac addresses are not required and when not specified, the add nodes workflow internally uses DHCP to assign an IP to a host.

Moreover, OCI instances can't know the mac addresses until they are booted which kind of gives a false impression that add nodes workflow can not be used for OCI ( Note: OCI can still use the add nodes command in 4.17 by providing a fake host mac address)

    4.18, 4.17

    Always

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