Tell the scheduler to target a specific compute on a nova boot

nova boot --flavor c7420f77-0cd8-4f48-a07c-abb80a669448 --image  ae8bc518-31f4-4b36-b8fd-5df49debef86  --nic net-id=dd71772f-567a-4944-a37c-457e0cbf3f84 --availability_zone nova:compute2 --poll first_guest_2

use metadatas

nova boot --key-name key_pub --meta keyservip=10.x.x.x --flavor 2 --image a29aef9b-53f0-44d5-b8d9-9829e2ec1f3e --availability-zone nova:compute1.silo3.ushou1.unifiedlayer.com --nic net-id=2261f182-809d-4ad3-bdb4-7a001c45f5fc --poll blake_metadata_test