###
# Does not work
###

### A
juju deploy --config /home/mosibi/openstack.cfg --constraints mem=20G cs:trusty/nova-compute


  "23":
    agent-state-info: '(error: cannot run instances: gomaasapi: got error back from
      server: 409 CONFLICT (No matching node is available.))'
    instance-id: pending
    series: trusty

### B
juju deploy --config /home/mosibi/openstack.cfg --constraints mem=20G cs:trusty/nova-compute


###
# Works
###
maas maas tags new name='compute' comment='compute nodes' definition='//node[@id="memory"]/size > 20000000000
juju deploy --config /home/mosibi/openstack.cfg --constraints tags=compute cs:trusty/nova-compute