You can use Ironic as a stand-alone component without other OpenStack services. Or, you can deploy it along with other OpenStack components, typically on the Compute node. The configuration would depend on how you deploy Ironic.
Provisioning Oracle Solaris bare metal instances requires an Automated Installer (AI). The AI can be located on the same node as the Ironic service. Alternatively, you can use AI on a remote server for operations with Ironic.
For more information about configuring and using AI, see the installation books in the applicable library in Operating System Documentation.