Just now RDO KIlo (RC2) does AIO packstack install with no problems ( actually, multi node as well )
View :- https://www.linux.com/community/blogs...
Skip part of procedure related to switching to Nova-Docker driver and stay with Libvirt one.
I realize that question was asked with Ubuntu 14.04 in the mind , so view :-
https://www.linux.com/community/blogs...
Just replace local.conf like this

   ubuntu@ubuntu-System:~$ cat local.conf
    [[local|localrc]]
    HOST_IP=192.168.1.51
    ADMIN_PASSWORD=secret
    DATABASE_PASSWORD=$ADMIN_PASSWORD
    RABBIT_PASSWORD=$ADMIN_PASSWORD
    SERVICE_PASSWORD=$ADMIN_PASSWORD
    SERVICE_TOKEN=a682f596-76f3-11e3-b3b2-e716f9080d50

    FLOATING_RANGE=192.168.12.0/24
    FLAT_INTERFACE=eth0
    Q_FLOATING_ALLOCATION_POOL=start=192.168.12.150,end=192.168.12.254
    PUBLIC_NETWORK_GATEWAY=192.168.12.15

    # Useful logging options for debugging:
    DEST=/opt/stack
    LOGFILE=$DEST/logs/stack.sh.log
    SCREEN_LOGDIR=$DEST/logs/screen

    # The default fixed range (10.0.0.0/24) conflicted with an address
    # range I was using locally.
    FIXED_RANGE=10.254.1.0/24
    NETWORK_GATEWAY=10.254.1.1

    # Services
    disable_service n-net
    enable_service n-cauth
    enable_service q-svc
    enable_service q-agt
    enable_service q-dhcp
    enable_service q-l3
    enable_service q-meta
    enable_service horizon
    disable_service tempest



  Regarding HA for Controllers it's a separate question.
    General concepts may be found here

http://docs.openstack.org/high-availa...

Just in case view also :- http://bderzhavets.blogspot.com/2015/...

Yes you can. But it will be a single point of failure.