This is a followup to the regression reported in https://bugs.launchpad.net/nova/+bug/1464239 The problem there was that Nova changed how it does block device mapping for ephemeral partitions, and because Ironic isn't using that block device mapping the ephemeral path returned by the metadata server became incorrect. I'm opening this bug because while it is possible to fix the regression, the behavior is still bad. The ephemeral partition metadata is only valid if Ironic happens to assign the ephemeral partition to /dev/sda1. This is often the case, but there are valid situations where it is not true - consider deploying to a vm where the ephemeral partition ends up on /dev/vda1.
Since I believe this would require a new method of synchronizing the block device mapping between Nova and Ironic, I'm pushing a fix for the regression to unbreak the previously working cases, and opening this bug to document that the situation is still not right.
Looks like this is the proposed change: https:/