What I've done to accomplish this task is to play with the image/volume and block storage services, via the Dashboard (sorry, am a little lazy to use the CLI right now): try this:

1. Upload your ISO image in ISO format
2. Create a Volume with Size according to the installation of your ISO image, be sure to mark it as bootable
3. Launch an instance from the ISO image, don't worry about the Flavor, just choose o create one that lets you build the instance.
4. BEFORE starting your installation of your ISO image, attach the volume you created on step 2 to this instance
5. Proceed with installation in the instance, be sure to identify the volume and install your distro or OS there.
6. Once you have finished the installation, stop the instance, detach the volume and you can safely delete the Instance
7. Go to Volumes, select the one you created and choose "Upload to Images"
8. Launch your new installed OS or Distro from the Image you've just created!

Hope this helps somebody :)

I found a sneaky way to do something like this. I can't guarantee it will work for you too, but I wanted to share it.

I am on Newton. basically you can change the libvirt xml file and the restart the instance via virsh fast enough that openstack doesn't re-write the xml file (until the instance is restarted normally)

so, make 2 volumes the first volume is a empty disk. say 40GB, no source, empty volume, bootable the second volume is created using the DVD ISO of the install media for source. say CentOS-4.8-64bit-binDVD.iso or any OS install, bootable.

create an instance using the first volume as vHD, when the instance boots it will fail because vda is a empty drive. note: there may also be a vdb if a metadata drive is being defined automatically.

attach the second DVD ISO volume to the instance, this may end up being vdc.

Boot the instance again to see it fails boot again for the same reason as above

find the hypervisor running the instance, and the instance's uuid

login to the hypervisor and find the instance you are working with "grep <uuid> /etc/libvirt/qemu"

say grep shows filename instance-00001cd1.xml

run "virsh edit instance-00001cd1"

reorder the <disk..... <="" disk=""> sections so that the vdc DVD ISO volume is first.

exit the editor and quickly "virsh destroy instance-00001cd1" (destroy is only a stop/shutdown)

and then quickly "virsh start instance-00001cd1"

if all has gone well openstack won't re-write to the instance-00001cd1.xml file and the DVD ISO volume will boot. check the console.

install the OS onto vdc and reboot the instance.

at this point the xml file will be re-written and the first volume will again be the first boot device and the newly installed OS will boot.

at this point you can detached the DVD ISO volume, vdc, if desired

worked for me! hope it works for you!

Since you are using a persistent volume, you could install the OS onto that volume, delete the instance (but retain the volume), then remount the volume inside a new instance which is not configured to use a CDROM.