Switch tripleo to use the ironic "direct" deploy interface - the "iscsi" interface is being deprecated and removed

[Harald Jensås]

Description of problem:
The ironic project is deprecating the iSCSI deploy interface, see[1].

TripleO support for the "direct" deploy interface was added in bp/ironic-direct-deploy[2].

With the iSCSI deploy interface being deprecated TripleO (OSP-director) need to start using the direct deploy interface by default.

Switching to use the direct interface was attempted before, but due to memory requirements on the baremetal nodes this was reverted. Later changes in ironic enable raw images streaming, which eliminates this problem. Images no longer need to be cached in ironic-python-agent memory.

[1] http://lists.openstack.org/pipermail/openstack-discuss/2020-August/016681.html
[1] https://review.opendev.org/#/q/topic:bp/ironic-direct-deploy

Expected results:

* Switch TripleO images from "qcow2" format to "raw" format.
* Make "direct" the default deploy interface.
* Depracate the "iscsi" interface in TripleO and disable it.

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.opendev.org/749465

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.opendev.org/749466

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.opendev.org/749917

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.opendev.org/749918

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.opendev.org/749931

[OpenStack Infra (hudson-openstack)]

Change abandoned by Harald Jensås (<email address hidden>) on branch: master
Review: https://review.opendev.org/749465
Reason: Yes, we can do the convert when importing.

[OpenStack Infra (hudson-openstack)]

Change abandoned by Harald Jensås (<email address hidden>) on branch: master
Review: https://review.opendev.org/749931
Reason: Will convert the image at import instead.

[OpenStack Infra (hudson-openstack)]

Change abandoned by Harald Jensås (<email address hidden>) on branch: master
Review: https://review.opendev.org/749917
Reason: Will convert at import instead.

[OpenStack Infra (hudson-openstack)]

Change abandoned by Harald Jensås (<email address hidden>) on branch: master
Review: https://review.opendev.org/749918

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/749466
Committed: https://git.openstack.org/cgit/openstack/python-tripleoclient/commit/?id=e21e04884e0a31be07e78d8ed65d6a18755a0e71
Submitter: Zuul
Branch: master

commit e21e04884e0a31be07e78d8ed65d6a18755a0e71
Author: Harald Jensås <email address hidden>
Date: Tue Sep 1 15:51:52 2020 +0200

    Convert to 'raw' images when uploading

    When using the ironic "direct" deploy interface RAW images
    are streamed to the target node. In comparison 'qcow2' images
    is transferred to the baremtal node and the image is then
    converted in to 'raw' in RAM. This put's a high RAM requirement
    on the baremetal nodes.

    This change updates the image upload/update code to convert
    the 'qcow2' image to a 'raw' image prior to upload/update.

    Related-Bug: #1893912
    Change-Id: I4774e6afc3844ee7c1e8900f2509a2c402abf490