From 0b86b7515131fff9e242f9fdcd64692d52b565ec Mon Sep 17 00:00:00 2001
From: Jesse Pretorius <jesse.pretorius@rackspace.co.uk>
Date: Fri, 28 Apr 2017 16:52:55 +0100
Subject: [PATCH] Perform an atomic policy file change

The policy.json file is currently read continually by the
services and is not only read on service start. We therefore
cannot template directly to the file read by the service
(if the service is already running) because the new policies
may not be valid until the service restarts. This is
particularly important during a major upgrade. We therefore
only put the policy file in place after the service restart.

This patch also tidies up the handlers and some of the install
tasks to simplify them and reduce the tasks/code a little.

Change-Id: I706d99cec90491216bb997ed06cbed6514e1b663
---
 handlers/main.yml                 | 49 +++++++++++++++++++++++++++++--
 tasks/ceilometer_init_common.yml  | 29 ------------------
 tasks/ceilometer_init_systemd.yml |  2 ++
 tasks/ceilometer_post_install.yml |  2 +-
 tasks/main.yml                    |  2 +-
 5 files changed, 50 insertions(+), 34 deletions(-)
 delete mode 100644 tasks/ceilometer_init_common.yml

diff --git a/handlers/main.yml b/handlers/main.yml
index 944d0e6e..e3cf9618 100644
--- a/handlers/main.yml
+++ b/handlers/main.yml
@@ -14,11 +14,54 @@
 # limitations under the License.
 
 - name: Restart ceilometer services
-  systemd:
+  debug:
+    msg: "Restarting services"
+  changed_when: true
+  notify:
+    - Stop services
+    - Copy new policy file into place
+    - Start services
+
+- name: Stop services
+  service:
     name: "{{ item.0.service_name }}"
-    state: "restarted"
-    daemon_reload: yes
+    enabled: yes
+    state: "stopped"
+    daemon_reload: "{{ (ansible_service_mgr == 'systemd') | ternary('yes', omit) }}"
   with_subelements:
     - "{{ ceilometer_services }}"
     - group
   when: inventory_hostname in groups[item.1]
+  register: _stop
+  until: _stop | success
+  retries: 5
+  delay: 2
+
+# Note (odyssey4me):
+# The policy.json file is currently read continually by the services
+# and is not only read on service start. We therefore cannot template
+# directly to the file read by the service because the new policies
+# may not be valid until the service restarts. This is particularly
+# important during a major upgrade. We therefore only put the policy
+# file in place after the service has been stopped.
+#
+- name: Copy new policy file into place
+  copy:
+    src: "/etc/ceilometer/policy.json-{{ ceilometer_venv_tag }}"
+    dest: "/etc/ceilometer/policy.json"
+    remote_src: yes
+
+- name: Start services
+  service:
+    name: "{{ item.0.service_name }}"
+    enabled: yes
+    state: "started"
+    daemon_reload: "{{ (ansible_service_mgr == 'systemd') | ternary('yes', omit) }}"
+  with_subelements:
+    - "{{ ceilometer_services }}"
+    - group
+  when: inventory_hostname in groups[item.1]
+  register: _start
+  until: _start | success
+  retries: 5
+  delay: 2
diff --git a/tasks/ceilometer_init_common.yml b/tasks/ceilometer_init_common.yml
deleted file mode 100644
index 278ca3cc..00000000
--- a/tasks/ceilometer_init_common.yml
+++ /dev/null
@@ -1,29 +0,0 @@
----
-# Copyright 2016, Rackspace US, Inc.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-# http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-- include: ceilometer_init_systemd.yml
-  when:
-    - ansible_service_mgr == 'systemd'
-
-- name: Load service
-  service:
-    name: "{{ item.0.service_name }}"
-    state: "restarted"
-  with_subelements:
-    - "{{ ceilometer_services }}"
-    - group
-  when: inventory_hostname in groups[item.1]
-  notify:
-    - Restart ceilometer services
diff --git a/tasks/ceilometer_init_systemd.yml b/tasks/ceilometer_init_systemd.yml
index ee937b00..dda226ac 100644
--- a/tasks/ceilometer_init_systemd.yml
+++ b/tasks/ceilometer_init_systemd.yml
@@ -60,6 +60,8 @@
     - "{{ ceilometer_services }}"
     - group
   when: inventory_hostname in groups[item.1]
+  notify:
+    - Restart ceilometer services
 
 - name: Place the systemd init script
   config_template:
diff --git a/tasks/ceilometer_post_install.yml b/tasks/ceilometer_post_install.yml
index b67e772b..309591be 100644
--- a/tasks/ceilometer_post_install.yml
+++ b/tasks/ceilometer_post_install.yml
@@ -85,7 +85,7 @@
       list_extend: false
       path: "etc/ceilometer/examples/"
     - name: "policy.json"
-      dest: "/etc/ceilometer/policy.json"
+      dest: "/etc/ceilometer/policy.json-{{ ceilometer_venv_tag }}"
       config_overrides: "{{ ceilometer_policy_overrides }}"
       config_type: "json"
     - name: "polling.yaml"
diff --git a/tasks/main.yml b/tasks/main.yml
index a6d37851..5dc758ef 100644
--- a/tasks/main.yml
+++ b/tasks/main.yml
@@ -44,7 +44,7 @@
   tags:
     - ceilometer-config
 
-- include: ceilometer_init_common.yml
+- include: "ceilometer_init_{{ ansible_service_mgr }}.yml"
   tags:
     - ceilometer-config