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: I2293575ad0422f546a2c4750f002955d75beb4d8

defaults/main.yml

@@ -19,6 +19,10 @@ nova_ceilometer_enabled: False
 ## Verbosity Options
 debug: False
 
+# Set the package install state for distribution packages
+# Options are 'present' and 'latest'
+nova_package_state: "latest"
+
 nova_git_repo: https://git.openstack.org/openstack/nova
 nova_git_install_branch: master
 nova_requirements_git_repo: https://git.openstack.org/openstack/requirements

releasenotes/notes/package-state-38187ec5242a005b.yaml

@@ -0,0 +1,13 @@
+---
+features:
+  - The os_nova 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
+    ``nova_package_state`` to ``present``.
+upgrade:
+  - The os_nova 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
+    ``nova_package_state`` should be set to ``present``.

tasks/nova_compute_powervm_install.yml

@@ -61,7 +61,7 @@
 - name: Install apt packages
   apt:
     pkg: "{{ item }}"
-    state: latest
+    state: "{{ nova_package_state }}"
   register: install_packages
   until: install_packages|success
   retries: 5

tasks/nova_install_apt.yml

@@ -16,6 +16,7 @@
 - name: Add Ubuntu Cloud Archive key package
   apt:
     pkg: ubuntu-cloud-keyring
+    state: "{{ nova_package_state }}"
   when: nova_uca_enable
   register: nova_uca_add_keys
   tags:
@@ -55,7 +56,7 @@
 - name: Install apt packages (common)
   apt:
     pkg: "{{ item }}"
-    state: latest
+    state: "{{ nova_package_state }}"
   register: install_packages
   until: install_packages|success
   retries: 5
@@ -85,7 +86,7 @@
 - name: Install apt packages (novnc console)
   apt:
     pkg: "{{ item }}"
-    state: latest
+    state: "{{ nova_package_state }}"
   register: install_packages
   until: install_packages|success
   retries: 5
@@ -102,7 +103,7 @@
 - name: Install apt packages (compute - KVM)
   apt:
     pkg: "{{ item }}"
-    state: latest
+    state: "{{ nova_package_state }}"
   register: install_packages
   until: install_packages|success
   retries: 5