Add ability to change apt/yum package state

The current method of installing the distribution packages required is
set in the tasks and cannot be changed by a deployer.

Currently the apt task always installs the latest package. This results
in unexpected binary changes when a deployer may simply be trying to
execute a configuration change.

This patch adds the ability for a deployer to change the desired state
so that the results are predictable.

Change-Id: Id0367754d3538c0e3da808521ba41b9aaa252a5f

defaults/main.yml

@@ -17,6 +17,10 @@
 galera_address: 127.0.0.1
 galera_root_user: root
 
+# Set the package install state for distribution packages
+# Options are 'present' and 'latest'
+galera_client_package_state: "latest"
+
 galera_client_drop_config_file: false
 
 galera_pinned_packages: []

releasenotes/notes/package-state-003ff33c557af3b5.yaml

@@ -0,0 +1,13 @@
+---
+features:
+  - The galera_client role now supports the ability to configure whether
+    apt/yum tasks install the latest available package, or just ensure
+    that the package is present. The default action is to ensure that
+    the latest package is present. The action taken may be changed to
+    only ensure that the package is present by setting
+    ``galera_client_package_state`` to ``present``.
+upgrade:
+  - The galera_client role always checks whether the latest package is
+    installed when executed. If a deployer wishes to change the check to
+    only validate the presence of the package, the option
+    ``galera_client_package_state`` should be set to ``present``.

tasks/galera_client_install_apt.yml

@@ -34,7 +34,7 @@
 - name: Ensure host can talk to HTTPS apt repos
   apt:
     pkg: "apt-transport-https"
-    state: latest
+    state: "{{ galera_client_package_state }}"
     update_cache: yes
   tags:
     - galera-client-apt-packages
@@ -91,7 +91,7 @@
 - name: Install galera packages
   apt:
     pkg: "{{ item }}"
-    state: latest
+    state: "{{ galera_client_package_state }}"
   register: install_packages
   until: install_packages | success
   retries: 5

tasks/galera_client_install_yum.yml

@@ -81,7 +81,7 @@
 - name: Install galera yum packages
   yum:
     pkg: "{{ item }}"
-    state: latest
+    state: "{{ galera_client_package_state }}"
   register: install_packages
   until: install_packages|success
   retries: 5