XenAPI: use dom0's hostname for nova-compute

When the virt dirver is xenapi, we should explicitly specify host
with dom0's hostname for nova-compute. The host field should be same
as neutron-openvswitch-agent-xenapi.

In order to use dom0's hostname, we need pull the bootstrap_xenapi
to before running nova config tasks. The dom0's hostname will be
included in the XenAPI facts.

Change-Id: Ibfc964bbd6c569062ad33c1399f9a4612baf5b92
blueprint: xenserver-support

ansible/roles/nova/tasks/bootstrap.yml

@@ -48,8 +48,3 @@
 
 - include: bootstrap_service.yml
   when: database.changed or use_preconfigured_databases | bool
-
-- include: bootstrap_xenapi.yml
-  when:
-    - inventory_hostname in groups['compute']
-    - nova_compute_virt_type == "xenapi"

ansible/roles/nova/tasks/config.yml

@@ -55,6 +55,13 @@
   notify:
     - "Restart {{ item.key }} container"
 
+- name: Set XenAPI facts
+  set_fact:
+    xenapi_facts: "{{ lookup('file', xenapi_facts_root + '/' + inventory_hostname + '/' + xenapi_facts_file) | from_json }}"
+  when:
+    - nova_compute_virt_type == 'xenapi'
+    - inventory_hostname in groups['compute']
+
 - name: Copying over nova.conf
   become: true
   vars:

ansible/roles/nova/tasks/deploy.yml

@@ -18,6 +18,11 @@
 - include: register.yml
   when: inventory_hostname in groups['nova-api']
 
+- include: bootstrap_xenapi.yml
+  when:
+    - inventory_hostname in groups['compute']
+    - nova_compute_virt_type == "xenapi"
+
 - include: config.yml
 
 - include: config-nova-fake.yml

ansible/roles/nova/templates/nova.conf.j2

@@ -35,6 +35,9 @@ compute_driver = fake.FakeDriver
 compute_driver = vmwareapi.VMwareVCDriver
 {% elif nova_compute_virt_type == 'xenapi' %}
 compute_driver = xenapi.XenAPIDriver
+{% if service_name == 'nova-compute' %}
+host = xenapi_facts['dom0_hostname']
+{% endif %}
 {% else %}
 compute_driver = libvirt.LibvirtDriver
 {% endif %}