ironic-agent element file type incosistency

[Lucas Alvares Gomes]

The "ramdisk-image-create" command outputs two files, one with a ".initramfs" extension and another with a ".kernel" extension.

The ironic-agent element creates a ramdisk but it doesn't rely on the "ramdisk-image-create" command instead it uses the "disk-image-create" command but outputs a .initramfs and .vmlinuz files.

For keeping the consistency and facilitate scripting against the DIB tool we should use the same file type for all ramdisks being created.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/210436

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/210436
Committed: https://git.openstack.org/cgit/openstack/diskimage-builder/commit/?id=ba808fa6ecfb71cd85976e153d7c7755b7a082d0
Submitter: Jenkins
Branch: master

commit ba808fa6ecfb71cd85976e153d7c7755b7a082d0
Author: Lucas Alvares Gomes <email address hidden>
Date: Fri Aug 7 13:45:12 2015 +0100

    ironic-agent element to output a .kernel file

    The ironic-agent element is created using the disk-image-create utility
    (even being a ramdisk) and outputs a .vmlinuz file for the kernel
    (different than the ramdisk-image-create which outputs a .kernel file
    for the kernel). This is inconsistent and make scripting against the
    diskimage-builder more complicated if one wants to support different
    types of ramdisk.

    This patch creates a hard link for the .vmlinuz file to a .kernel file
    at the end of the process (to keep backward compatibility) and print a
    deprecation message.

    Depends-On: I81400305f166d62aa4612aab54602abb8178b64c
    Change-Id: I476f9ec9ec4206ece0261eaaf2b4182c6bcbd802
    Closes-Bug: #1482606