XenAPI: Support compute node bootstrap

This is to add a bootstrap task for XenAPI to bootstrap the compute
node. One compute node is composed with a XenServer and a DomU VM
running on the XenServer. Before it's ready for deploying OpenStack
sevices on it, we need bootstrap it firstly. The package of
python-os-xenapi contains a tool and some utils which were developed
to finish all of the needed bootstrap tasks
e.g.:
1. configure himn(host internal management network)
2. configure ipatables to allow traffic
3. install xapi plugins to dom0
4. gather XenAPI facts and save them into a file
...

The task added in this commit is to invoke that tool so that the
bootstrap tasks can be completed automatically during kolla deployment.

Depends-On: Ie2d7d40f2755580aac4a10f3d302190a8bd4fe6f
Change-Id: I1500535a1c9a085bcbfec5db5fbddcf040e6892d
blueprint: xenserver-support

ansible/group_vars/all.yml

@@ -725,3 +725,5 @@ opendaylight_allowed_network_types: '"flat", "vlan", "vxlan"'
 xenserver_himn_ip: "169.254.0.1"
 xenserver_username: "root"
 xenserver_connect_protocol: "https"
+# File used to save XenAPI's facts variables formatted as json.
+xenapi_facts_file: "/etc/kolla/xenapi.json"

ansible/roles/nova/tasks/bootstrap.yml

@@ -45,3 +45,8 @@
 
 - include: bootstrap_service.yml
   when: database.changed
+
+- include: bootstrap_xenapi.yml
+  when:
+    - inventory_hostname in groups['compute']
+    - nova_compute_virt_type == "xenapi"

ansible/roles/nova/tasks/bootstrap_xenapi.yml

@@ -0,0 +1,9 @@
+- name: Install package python-os-xenapi
+  package:
+    name: python-os-xenapi
+    state: present
+  become: True
+
+- name: Bootstrap XenAPI compute node
+  command: xenapi_bootstrap -i {{ xenserver_himn_ip }} -u {{ xenserver_username }} -p {{ xenserver_password }} -f {{ xenapi_facts_file }}
+  become: True