Load and persist modules from the host.

This reusable ansible role will be used in tripleo-heat-templates
in order to load known kernel modules such as ip_vs, iscsi and some
other that are for now loaded from within the containers.

Change-Id: Ic9076a0a1a8e1360495dcf0eb766118ec63dc362

releasenotes/notes/tripleo-module-load-80f7fd8c8dd6a81e.yaml

@@ -0,0 +1,3 @@
+---
+features:
+  - Loads and persist kernel modules from the host directly.

roles/tripleo-module-load/defaults/main.yaml

@@ -0,0 +1,7 @@
+---
+# Module name as a list of hashes:
+# modules:
+#   - { name: foo, params: 'bar baz' }
+#   - { name: starwars }
+#   - { name: starwars, state: absent }
+modules: []

roles/tripleo-module-load/tasks/main.yaml

@@ -0,0 +1,52 @@
+---
+# Allow to get a clean way to load and persist kernel modules
+
+- name: Check whether /etc/modules-load.d exists
+  stat:
+    path: /etc/modules-load.d
+  register: modules_load_stat
+
+- name: "Load modules"
+  become: true
+  modprobe:
+    name: "{{ item.name }}"
+    params: "{{ item.params | default(omit) }}"
+    state: "{{ item.state | default('present') }}"
+  loop: "{{ modules }}"
+  loop_control:
+    label: "{{ item.name }}"
+
+- name: "Persist modules via modules-load.d"
+  become: true
+  template:
+    dest: "/etc/modules-load.d/{{ item.name }}.conf"
+    src: module-load.conf.j2
+  loop: "{{ modules }}"
+  loop_control:
+    label: "{{ item.name }}"
+  when:
+    - modules_load_stat.stat.exists
+    - (item.state | default('present')) == 'present'
+
+- name: "Drop module persistence"
+  become: true
+  file:
+    path: "/etc/modules-load.d/{{ item.name }}.conf"
+    state: absent
+  loop: "{{ modules }}"
+  loop_control:
+    label: "{{ item.name }}"
+  when:
+    - modules_load_stat.stat.exists
+    - (item.state | default('present')) == 'absent'
+
+- name: "Set modules persistence via /etc/modules"
+  become: true
+  lineinfile:
+    dest: /etc/modules
+    line: "{{ item.name }} {{ item.params | default('') }}"
+    state: "{{ item.state | default('present') }}"
+  loop: "{{ modules }}"
+  loop_control:
+    label: "{{ item.name }}"
+  when: not modules_load_stat.stat.exists

roles/tripleo-module-load/templates/module-load.conf.j2

@@ -0,0 +1,2 @@
+# {{ ansible_managed }}
+{{ item.name }} {{ item.params |default('') }}