Use group_names to check a host belongs to group

group_names is one of magic variables from Ansible [1] which is a
list of all groups the current host is in, using this syntax will be
more readable and avoid assuming that specific group is already defined
in inventory. Another use case is if we want to run a task only if the
host does not belong to a certain group.

This also makes consitent with some usages in current code [2].

[1]
http://docs.ansible.com/ansible/latest/playbooks_variables.html#magic-variables-and-how-to-access-information-about-other-hosts
[2]
https://github.com/openstack/openstack-ansible-os_cinder/blob/master/tasks/main.yml#L70

Change-Id: I7f85e18829cd3c9835f592ceb74f4e6460208ca6

tasks/cinder_post_install.yml

@@ -62,7 +62,7 @@
     state: present
   notify: Ensure tgt service restarted
   when:
-    - inventory_hostname in groups['cinder_volume']
+    - "cinder_services['cinder-volume']['group'] in group_names"
     - cinder_backend_lvm_inuse | bool
 
 - name: Create nfs shares export file
@@ -71,8 +71,8 @@
     dest: "{{ item.value.nfs_shares_config }}"
   with_dict: "{{ cinder_backends | default({}) }}"
   when:
+    - "cinder_services['cinder-volume']['group'] in group_names"
     - item.value.nfs_shares_config is defined
-    - inventory_hostname in groups['cinder_volume']
   tags:
     - cinder-nfs
 

tasks/main.yml

@@ -54,7 +54,7 @@
   static: no
   when:
     - "groups['cinder_api'] | length > 0"
-    - "'cinder_api' in group_names"
+    - "cinder_services['cinder-api']['group'] in group_names"
     - "inventory_hostname == ((groups['cinder_api'] | intersect(ansible_play_hosts)) | list)[0]"
   tags:
     - cinder-config
@@ -67,7 +67,7 @@
   static: no
   when:
     - "groups['cinder_api'] | length > 0"
-    - "'cinder_api' in group_names"
+    - "cinder_services['cinder-api']['group'] in group_names"
     - "inventory_hostname == ((groups['cinder_api'] | intersect(ansible_play_hosts)) | list)[0]"
   tags:
     - cinder-config
@@ -83,7 +83,7 @@
     openstack_service_system_user: "{{ cinder_system_user_name }}"
     openstack_service_venv_bin: "{{ cinder_bin }}"
   when:
-    - "'cinder_volume' in group_names"
+    - "cinder_services['cinder-volume']['group'] in group_names"
     - "cinder_backend_rbd_inuse | bool"
   tags:
     - ceph
@@ -95,14 +95,14 @@
   static: no
   when:
     - "groups['cinder_volume'] | length > 0"
-    - "'cinder_volume' in group_names"
+    - "cinder_services['cinder-volume']['group'] in group_names"
     - "inventory_hostname == ((groups['cinder_volume'] | intersect(ansible_play_hosts)) | list)[0]"
   tags:
     - cinder-config
 
 - include: cinder_lvm_config.yml
   when:
-    - "'cinder_volume' in group_names"
+    - "cinder_services['cinder-volume']['group'] in group_names"
     - "cinder_backend_lvm_inuse | bool"
   tags:
     - cinder-config

templates/cinder.conf.j2

@@ -18,7 +18,7 @@ enable_v1_api = {{ cinder_enable_v1_api }}
 enable_v2_api = {{ cinder_enable_v2_api }}
 enable_v3_api = {{ cinder_enable_v3_api }}
 
-{% if inventory_hostname in groups['cinder_volume'] %}
+{% if cinder_services['cinder-volume']['group'] in group_names %}
 {% if cinder_service_backup_program_enabled == true %}
 ## Cinder Backup
 backup_driver = {{ cinder_service_backup_driver }}