Rabbit policies now overrideable by deployers

Previously the role assumed that all deployers wanted
all queues to be HA. Performance testing by Mirantis and
Intel has suggested that throughput increases can be dramatic
when disabling HA queues, see:
  http://docs.openstack.org/developer/performance-docs/test_results/mq/rabbitmq/index.html

Therefore, we should allow deployers to set their own
policies when desired.

Change-Id: I156b8618e78d74823ec568053157afc853baad84
Closes-Bug: #1607830

defaults/main.yml

@@ -82,3 +82,32 @@ rabbitmq_management_rates_mode: basic
 
 # Precompile RabbitMQ with HiPE
 rabbitmq_hipe_compile: False
+
+# RabbitMQ policies
+# Used to tune performance characteristics of OpenStack messaging
+#
+# Example override that uses HA queues only for telemetry and sets message
+# expiry for RPC messages
+#
+# rabbitmq_policies:
+#   - name: "heat_rpc_expire"
+#     pattern: '^heat-engine-listener\\.'
+#     tags: "expires=3600000"
+#     priority: 1
+#   - name: "results_expire"
+#     pattern: '^results\\.'
+#     tags: "expires=3600000"
+#     priority: 1
+#   - name: "tasks_expire"
+#     pattern: '^results\\.'
+#     tags: "expires=3600000"
+#     priority: 1
+#   - name: "ha-notif"
+#     pattern: '^(event|metering|notifications)\.'
+#     tags: "ha-sync-mode=automatic"
+#     priority: 0
+#
+rabbitmq_policies:
+  - name: "HA"
+    pattern: '^(?!amq\.).*'
+    tags: "ha-mode=all"

releasenotes/notes/policy-override-522df5699f09c417.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - The ``rabbitmq_server`` role now supports deployer override of the
+    RabbitMQ policies applied to the cluster. Deployers can
+    override the ``rabbitmq_policies`` variable, providing a list of
+    desired policies.

tasks/rabbitmq_post_install.yml

@@ -25,10 +25,12 @@
 - name: Enable queue mirroring
   rabbitmq_policy:
     node: "rabbit@{{ ansible_hostname }}"
-    name: "HA"
-    pattern: '^(?!amq\.).*'
-    tags: "ha-mode=all"
+    name: "{{ item.name }}"
+    pattern: "{{ item.pattern }}"
+    priority: "{{ item.priority | default(0) }}"
+    tags: "{{ item.tags }}"
   register: rabbitmq_queue_mirror
+  with_items: "{{ rabbitmq_policies }}"
   tags:
     - rabbitmq-config
     - rabbitmq-cluster

tests/test-rabbitmq-server-functional.yml

@@ -65,3 +65,12 @@
     - name: Ensure expected version of rabbitmq is running
       assert:
         that: rabbitmqctl_status.stdout | search ("rabbit,\"RabbitMQ\",\"{{ rabbitmq_release_version }}\"")
+    - name: Get the policy list
+      command: rabbitmqctl -q list_policies
+      register: rabbitmq_policies_output
+    - debug:
+        var: rabbitmq_policies.stdout
+    # Expected policy: "/       HA      all     ^(?!amq\\.).*   {"ha-mode":"all"}       0"
+    - name: Validate that the expected policies are present
+      assert:
+        that: rabbitmq_policies_output.stdout | search("amq")