Fix module loading on centos hosts.

Introducing a new var: {{ openstask_host_module_file }} that contain
the path to the file containing module list.

Centos will use systemd-modules-load.service:
- http://www.unix.com/man-page/centos/8/systemd-modules-load.service/
- http://www.unix.com/man-page/centos/5/modules-load.d/

Change-Id: I9ce294045259752e48c47ed036a9550565f05bc5

tasks/openstack_kernel_modules.yml

@@ -23,8 +23,9 @@
 
 - name: "Ensure kernel module(s) loaded at boot"
   lineinfile:
-    dest: /etc/modules
+    dest: "{{ openstask_host_module_file }}"
     line: "{{ item }}"
+    create: yes
   with_items: "{{ openstack_host_kernel_modules }}"
   when:
     - openstack_host_kernel_modules | length > 0
@@ -71,7 +72,7 @@
 
 - name: "Ensure dynamic specific kernel module(s) loaded at boot"
   lineinfile:
-    dest: /etc/modules
+    dest: "{{ openstask_host_module_file }}"
     line: "{{ item['item']['name'] }}"
   with_items: "{{ modules['results'] | default([]) }}"
   when:

tests/test.yml

@@ -30,7 +30,7 @@
   post_tasks:
     - name: Open modules file
       slurp:
-        src: /etc/modules
+        src: "{{ openstask_host_module_file }}"
       register: modules_file
     - name: Open sysctl file
       slurp:

vars/redhat-7.yml

@@ -17,6 +17,7 @@
 openstack_host_required_kernel: 3.10.0-327.13.1.el7.x86_64
 openstack_host_sysstat_file: /etc/sysconfig/sysstat
 openstack_host_cron_template: sysstat.cron.redhat.j2
+openstask_host_module_file: /etc/modules-load.d/openstack-ansible.conf
 
 ## Kernel modules loaded on hosts
 openstack_host_kernel_modules:

vars/ubuntu-14.04.yml

@@ -20,6 +20,7 @@ cache_timeout: 600
 openstack_host_required_kernel: 3.13.0-34-generic
 openstack_host_sysstat_file: /etc/default/systat
 openstack_host_cron_template: sysstat.cron.debian.j2
+openstask_host_module_file: /etc/modules
 
 ## Kernel modules loaded on hosts
 openstack_host_kernel_modules:

vars/ubuntu-16.04.yml

@@ -20,6 +20,7 @@ cache_timeout: 600
 openstack_host_required_kernel: 4.2.0-18-generic
 openstack_host_sysstat_file: /etc/default/systat
 openstack_host_cron_template: sysstat.cron.debian.j2
+openstask_host_module_file: /etc/modules
 
 ## Kernel modules loaded on hosts
 openstack_host_kernel_modules: