Add new oc_hosts_roles variable.

With the new upgrades workflow we need to perform a more
granular upgrade node by node, instead of by role as we
were doing before. For that reason, we're adding a new
variable which contains all the hosts an ansible group
consists of. So we can iterate over them at the time of
upgrading.

Change-Id: I81f4add06218ad201d4772821723154c33d4123e

defaults/main.yml

@@ -237,6 +237,13 @@ upgrade_remove_rpm: false
 # List of roles deployed in overcloud
 oc_roles: []
 
+# Dictionary with roles and hosts per role
+# oc_roles_hosts: {
+# 'Controller' : ["controller-0", "controller-1", "controller-2"],
+# 'Compute' : ["compute-0"]
+# }
+oc_roles_hosts: {}
+
 # Roles upgrade order
 roles_upgrade_order: '__undefined__'
 

tasks/common/load_roles_from_inventory.yaml

@@ -30,3 +30,10 @@
   set_fact:
     oc_roles: "{{ roles_upgrade_order.split(';') }}"
   when: roles_upgrade_order != '__undefined__'
+
+- name: create hosts per role fact
+  vars:
+    inventory_yaml: "{{ upgrade_tripleo_inventory.stdout | from_yaml }}"
+  set_fact:
+    oc_roles_hosts: "{{ oc_roles_hosts | combine({ item.key : inventory_yaml[item.key]['hosts'].keys() }) }}"
+  with_dict: "{{ inventory_yaml.overcloud.children }}"