[RFE] Clean up UEFI boot options before booting an ISO

[Dmitry Tantsur]

As explained in https://storyboard.openstack.org/#!/story/2008763 having boot options related to non-existing paths can prevent the node from booting. Using Redfish, we can at least try purging wrong items before booting.

While the implementation is not yet agreed upon, one way to do would be to update the Ironic's prepare_ramdisk code to check the BootOptions collection of a System, match each option's UefiDevicePath against a CD pattern and drop the BootOptionReference of the found items from the System's BootOrder (directly or using @Settings).

NOTE: It is critical to do this operation out-of-band before we try to boot the ramdisk for inspection or deployment (unless already fast-tracking), as well as during the preparation for the ramdisk deploy.

[Steve Baker (steve-stevebaker)]

Should we close this as a duplicate of https://bugs.launchpad.net/ironic/+bug/2041901?