Description:

Currently, users need to manually override the EDPM Ansible variables for each dataplane image to use images from custom registries. Ideally, we can infer from the state of the OCP cluster whether we need to operate with a private registry as well. In such cases, we can just copy the same `registries.conf` file used by OCP nodes to configure mirrors for the registry.

This would allow us to maintain static defaults in the `OpenStackVersion` resource, and place the burden of pulling image from the private registries onto the container runtime engine on the dataplane nodes. This approach would also be consistent with OpenShift allowing for less friction while debugging and a more intuitive integration point.

Approach

Introduce a library to openstack-operator (dataplane) that is able to:

1. Determine the disconnected status of the OCP cluster based on the existence of ImageContentSourcePolicy objects.
2. In cases where we determine that the cluster is using a private registry, we will copy the registries.conf file directly from the `99-master-generated-registries` `MachineConfig` and pass that value to Ansible during the deployment and configuration of `edpm_podman`.