Some Tempest tests require booting multiple instances at once, but we only deploy 1 Ironic node

[Adam Gandelman]

Some compute API tests require booting multiple instances during a single test or single test case, ie:

tempest.api.compute.floating_ips.test_floating_ips_actions
tempest.api.compute.images.test_images_negative
tempest.api.compute.servers.test_create_server
 tempest.api.compute.servers.test_list_servers

The current Ironic devstack-gate deployment sets up Ironic with a single VM enrolled as a single Ironic node. Once this has been provisioned, there are no more resources available for additional test instances.

Some solutions:

 -Tempest needs to have a configurable limit to the number of instances that can be spawned at once
 - Ironic+Devstack deployment should set quota limits based on IRONIC_VM_COUNT
 - Adjust IRONIC_VM_COUNT in the devstack-gate job to match needs of Tempest.. not sure how well the devstack slave nodes would handle deploying many Ironic instances. tempest.api.compute.servers.test_list_servers creates a total of 3 servers at once, which I believe is the max.

[David Kranz (david-kranz)]

This issue should be solved on the ironic side. Tempest assumes a modest level of resources which should be met when using it. The multi-server tests can be skipped if running in a limited server environment.