The most possible and typical failures of Ironic are caused by the following peculiarities of the service design:
Ironic is sensitive to possible time difference between the nodes that host
the ironic-api and ironic-conductor services.
One of the symptoms of time being out of sync is inability to enroll a
bare metal node into Ironic with the error message
No conductor service registered which supports driver <DRIVER_NAME>
Although, the DRIVER_NAME driver is known to be enabled and is shown
in the output of the ironic driver-list command.
To fix the issue, verify that the time is properly synced between the nodes.
Ironic requires IPMI access credentials for the nodes to have the admin
privilege level. Any lower privilege level, for example, engineer
precludes Ironic from functioning properly.