Do not overwrite the iPXE boot script for every deployment

[Lucas Alvares Gomes]

The iPXE boot script (default boot.ipxe [1]) gets overwritten for every node deployment, this script is unique for all deployments so we don't need to rewrite it all the time.

Also sometimes one may want to changing the content of the file to test a deployment (i.e something like [2]), but since Ironic always overwrite the file testing it gets more painful than it should.

[1] https://github.com/openstack/ironic/blob/master/ironic/drivers/modules/boot.ipxe
[2] https://bugs.launchpad.net/ironic/+bug/1486950

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/218290

[Julia Kreger (juliaashleykreger)]

This fix is necessary as bifrost carries support for broken ipxe implementations by enabling them to chain-load to a current version and then proceed. Without it, bifrost looses that support.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/218290
Committed: https://git.openstack.org/cgit/openstack/ironic/commit/?id=d72493deb21db90961c80757fd81d30fb39a43c8
Submitter: Jenkins
Branch: master

commit d72493deb21db90961c80757fd81d30fb39a43c8
Author: Lucas Alvares Gomes <email address hidden>
Date: Fri Aug 28 15:19:30 2015 +0100

    Do not overwrite the iPXE boot script on every deployment

    This patch just add a check to verify if the iPXE boot script have already
    been laid down in the HTTP root directory and do not overwrite it if
    it's already there. The script is the same for all deployments so we
    don't need to write it over and over. This also makes it easier to test
    some custom parameter in the script without having to deal with Ironic
    undoing the changes prior to deploy a node.

    Closes-Bug: #1489904
    Change-Id: I0d56767978a6d1290442e50d7cb1308d78e3a352

[Lucas Alvares Gomes (lucasagomes)]

This bug is being reverted at https://review.openstack.org/219749

The change brings more risks than benefits