Multiple instance launch from volume allowed

[Valentyn Khalin]

Detailed bug description:
When you launch instance via Horizon from volume it allows you to do that multiple times when you hit "Lunch instance" button.

Normal behavior should be:
- when you hit "Lunch instance" button it becomes freezed till instance will be launched
- when you hit "Lunch instance" button volume/snapshot (or any other boot source which will be 'in use' after instance is launched) should be freezed also
- volume/snapshot should be not accessile for new instance launch as it is "in use" right after button was hit

Steps to reproduce:
- open Horizon dashboard. One of the newest one which uses Javascript for popup windows like instance launch
- open Volumes tab and create bootable volume
- hit "Launch as instance" button to open popup window
- fill all necessary tabs and "Launch instance" button will be available
- hit quickly "Launch instance" button few times
- check running instances in "Instances" tab

Expected results:
- when you hit "Lunch instance" button it becomes freezed till instance will be launched
- when you hit "Lunch instance" button volume/snapshot (or any other boot source which will be 'in use' after instance is launched) should be freezed also
- volume/snapshot should be not accessile for new instance launch as it is "in use" right after button was hit

Actual result:
- you're able to launch multiple instances from volume

Reproducibility:
- Horizon in Liberty release, upstream OS
- all envs with Horizon that uses Javascript for "Launch instance" window

Workaround:
- inform customer about that bug

[Valentyn Khalin (vkhalin)]

Can't reproduce right now on environments. Will reopen this bug if problem occurs.

[Ievgeniia Zadorozhna (izadorozhna)]

As well as with Horizon button that is not disabled after hitting "Launch" (bug description), this bug was reproduced also via CLI.

Steps to reproduce:
1. Create volume:
cinder create 1 --name test_10_05 --volume-type ceph
2. Make it bootable:
cinder set-bootable test_10_05 true
3. Boot 3 VMs in a cycle using single volume as a boot source:
for i in `seq 1 3`; do openstack server create --flavor m1.medium --volume 21d25bcf-d8ca-4988-8163-7868c197f103 --nic net-id=04b19fd4-0585-42a6-8a86-e71e86d2517e --block-device source=volume,id=21d25bcf-d8ca-4988-8163-7868c197f103,dest=volume,size=1,shutdown=preserve izadorozhna_test_10_05 && date; done; cinder show 21d25bcf-d8ca-4988-8163-7868c197f103;

Expected result:
Only one instance can be booted from one volume (with multiattach=False) option.

Actual result:
All 3 instances were created with the same volume attached. The volume had 3 attachments:
| attachments | [{u'server_id': u'aac49a85-39d1-4def-9b3c-310f9d0fc30e', u'attachment_id': u'7ca7912a-404d-4442-89a7-75d7b3459333', u'host_name': None, u'volume_id': u'21d25bcf-d8ca-4988-8163-7868c197f103', u'device': u'/dev/vda', u'id': u'21d25bcf-d8ca-4988-8163-7868c197f103'}] |