openstack
/
ironic-specs
Code Issues Proposed changes

Amend ipxe-swift-tempurls spec 

The corresponding patch was merged.

The spec is amended with actual implementation details:
- actual config option names
- caching behavior for kernel/ramdisk of user image for netboot case

Change-Id: I0053b3790a2da36f5df1b649e31acb7cba55442b
Related-Bug: #1526404
This commit is contained in:
Pavlo Shchelokovskyy 2016-09-19 21:22:20 +03:00 committed by Ruby Loo
parent 31a35536a8
commit 964f07e720
1 changed files with 16 additions and 12 deletions
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28
specs/approved/ipxe-swift-tempurls.rst
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@ -11,13 +11,13 @@ iPXE to use Swift Temporary URLs
https://bugs.launchpad.net/ironic/+bug/1526404
This adds support for generating Swift temporary URLs for the
deploy and image's ramdisk(s) and kernel(s) when booting with iPXE.
deploy ramdisk and kernel when booting with iPXE.
Problem description
===================
Currently the iPXE driver requires an external HTTP server to serve
the deploy and image's ramdisk and kernel. When used with Glance, the
the deploy ramdisk and kernel. When used with Glance, the
``ironic-conductor`` fetches the images from it and place them under the
HTTP root directory, and if a rebalance happens in the hash right the
new ``ironic-conductor`` taking over the node have to do the same thing,
@ -31,15 +31,21 @@ Proposed change
===============
The proposed implementation consists in having the iPXE driver to create
a Swift tempurl for the ramdisk and kernel (deploy or image) that the
a Swift tempurl for the deploy ramdisk and kernel that the
node will boot as part of the config generation.
This also proposes adding a boolean configuration option under
the ``ipxe`` group called ``use_swift``. If True this will tell iPXE to
the ``pxe`` group called ``ipxe_use_swift``. If True this will tell iPXE to
not cache the images in the disk and generate the Swift tempurl for the
ramdisk and kernel, if False, iPXE will continue to cache the images
under the HTTP root directory. Defaults to False.
Note that in order to keep compatibility with Nova behavior,
kernel/ramdisk of the user image still have to be cached in case
``netboot`` is required. Doing otherwise will make it impossible for user
to reboot the instance from within when tempurls have expired or the image
is deleted from Glance altogether.
Alternatives
------------
@ -131,24 +137,22 @@ Primary assignee:
lucasagomes <lucasagomes@gmail.com>
Other contributors:
pshchelo <shchelokovskyy@gmail.com>
Work Items
----------
* Add the new ``use_swift`` configuration option under the ``ipxe`` group.
* Add the new ``ipxe_use_swift`` configuration option under the ``pxe`` group.
* Get the iPXE driver to generate the Swift temporary URLs as part of
the configuration generation when ``use_swift`` is True.
* Get the PXE driver to generate the Swift temporary URLs as part of
the configuration generation when ``ipxe_use_swift`` is True.
* Skip caching the image on the disk when ``use_swift`` is True.
* Skip caching the image on the disk when ``ipxe_use_swift`` is True.
Dependencies
============
* This patch depends on the specification `ipxe-dymic-config
<https://review.openstack.org/#/c/177726/>`_ that makes the iPXE
configuration files to be dynamically generated.
None
Testing
=======