nova boot baremetal, select specific machine in pool to 'boot' - openstack

Question

I am using Ironic to help me deploy bare metal in a data center environment using 1U Dell servers. It works very well, I can use Ironic to marshall dozens of servers in the rack, then when I need a bare metal instance (via nova) I just use the flavor associated with those servers and I get one of them. Is there a way I can get a specific one? For example, my servers are numbered from the top, starting with control0, control1 all the way down to control39. So, first I create all of the baremetal servers, introspect them. Then I create a flavor (like below, please forgive the pseudo code) and associate each baremetal server with that profile.
openstack flavor create --id auto --ram 6144 --disk 40 --vcpus 4 control
openstack flavor set --property "cpu_arch"="x86_64" --property "capabilities:boot_option"="local" --property "capabilities:profile"="control" control
i = 0
for each baremetal server's uuid:
ironic node-update server-uuid add name=control$i
i = i + 1
ironic node-update server-uuid add properties/capabilities="profile:control,boot_option:local"
When I loop through the list I know that the servers are in top down physical order. What I would like to be able to do is get nova to create a boot instance on a specific ironic bare metal (like control3). I could create separate flavors for each one but I think there must be a way to select a specific piece of hardware? Or a strategy that would pick them in the order I specify.
I am pretty new to Ironic. I have done quite a bit of googling on the topic but haven't found anything. Here is how I start nova:
nova boot --flavor control --image rhel-server-7.1-x86_64-dvd.iso --nic 'net-id=723e7b11-3e61-481a-827e-e58b369dd28f' mybootinstance1
Which works fine. What I would like to do is have a nova boot line which uses the flavor control, and also the name (control0) or any other property that I can assign to make that machine unique. Something like:
nova boot --flavor control --ironic-instance-name control0 --image rhel-server-7.1-x86_64-dvd.iso --nic 'net-id=723e7b11-3e61-481a-827e-e58b369dd28f' mybootinstance1
This is actually a simplification of the nova pool selection process. I don't want to use a pool, but rather, a specific piece of hardware.
If that isn't possible, is there a big drawback to using 40 flavors to create individual 'pools'?

Answer 1

I think you can use --hint in nova boot to select specific machine in pool.
Preconditions: edit /etc/nova/nova.conf, add 'JsonFilter' in scheduler_default_filters and restart nova-scheduler.Then use nova boot command like this:
nova boot --flavor <flavor> --image <image_id> --nic net-id=<net_id> --hint reservation=<reservation_id> --hint query='["=","$hypervisor_hostname", "<node_uuid>"]' <instance_name>

Answer 2

I'm not quite familiar to this topic, but I'd like to share how to boot an instance to specific host via availability zone.
In my devstack (master) development environment, the procedure is:
$ nova availability-zone-list
+---------------------+----------------------------------------+
| Name | Status |
+---------------------+----------------------------------------+
| internal | available |
| |- fcwszq | |
| | |- nova-conductor | enabled :-) 2015-11-23T06:31:46.000000 |
| | |- nova-cert | enabled :-) 2015-11-23T06:31:41.000000 |
| | |- nova-scheduler | enabled :-) 2015-11-23T06:31:43.000000 |
| | |- nova-network | enabled :-) 2015-11-23T06:31:44.000000 |
| nova | available |
| |- fcwszq | |
| | |- nova-compute | enabled :-) 2015-11-23T06:31:41.000000 |
+---------------------+----------------------------------------+
Note that my environment only gets one compute node whose hostname is fcwszq, but still can be specified as:
nova boot --availability-zone nova:fcwszq --flavor 1 --image c38f0c7e-8ee0-4b0f-8a56-022040b4696f test02
If I specify a non-existent node, for example, nova:non-existent, the instance cannot be created correctly (state is ERROR).
Hope this can help you.
Another way is using host aggregate and flavor metadata to boot instance on a random server in a group, reference: http://docs.openstack.org/liberty/config-reference/content/section_compute-scheduler.html#d6e21786