ramdisk-functions replace the contents of /etc/modprobe.d/blacklist.conf with "blacklist evbug" only

[Nisha Agarwal]

lib/ramdisk-functions replace the contents of /etc/modprobe.d/blacklist.conf with "blacklist evbug" only. The code does following:
echo "blacklist evbug" > "$TMP_MOUNT_PATH/etc/modprobe.d/blacklist.conf"

While it should do "echo "blacklist evbug" >> "$TMP_MOUNT_PATH/etc/modprobe.d/blacklist.conf"" after writing the contents of modprobe.d/blacklist.conf to the image.

Anything written to blacklist.conf by the elements is replaced by "blacklist evbug". This prevents the ramdisk to boot successfully when an element depends on the blacklist.conf.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/220883

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/220883
Committed: https://git.openstack.org/cgit/openstack/diskimage-builder/commit/?id=d9ce041237cb88b5d278d925b4ef27510c344ecc
Submitter: Jenkins
Branch: master

commit d9ce041237cb88b5d278d925b4ef27510c344ecc
Author: Nisha Agarwal <email address hidden>
Date: Sun Sep 6 22:52:16 2015 -0700

    Prevent overwriting of user modified blacklist.conf

    The ramdisk-functions overwrites user modified
    /etc/modprobe.d/blacklist.conf with a single entry
    "blacklist evbug". Due to this, ramdisk fails to recognise
    the hardware/disks etc for which user has modified
    /etc/modprobe.d/blacklist.conf.
    The commit enables copying all the *.conf files under
    /etc/modprobe.d to the ramdisk. It creates
    a config file /etc/modprobe.d/blacklist-dib-ramdisk.conf
    instead of overwriting /etc/modprobe.d/blacklist.conf.

    Closes bug: #1492804

    Change-Id: Ib88272e4b8f4641c58e7e68bb0c2e4b82efc4fc1