Filter Gnocchi traffic optionally

When using Swift storage for Gnocchi we want to add a filter to the
Ceilometer middleware for Swift to exclude reporting traffic caused
by Gnocchi storing data into Swift to avoid feedback-loops. This
is typically done by isolating the Gnocchi in a dedicated Project in
Keystone.

The best place to filter this traffic is in the middleware
as opposed to filtering in the Ceilometer Collector.

Related-To: I67b5bff394ad35cf95d10ba32d602954799d7348
Change-Id: If20248494d4e6c127db4ffdf77ae43482f64fe58

defaults/main.yml

@@ -13,8 +13,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Enable/Disable Ceilometer
+# Enable/Disable Telemetry projects
 swift_ceilometer_enabled: False
+swift_gnocchi_enabled: False
 
 ## Verbosity Options
 debug: False

tasks/swift_service_setup.yml

@@ -168,3 +168,31 @@
   until: add_service|success
   retries: 5
   delay: 10
+
+# KNOWN ISSUE(stevelle) Never fail. Swift playbook runs before Gnocchi in a
+# standard deploy. The project for Gnocchi will not have been created yet.
+# There is a known issue in project / user / role lifecycles that causes a
+# circular service dependency here. The Swift playbook must be run a second
+# time, after the Gnocchi playbook runs, when it uses Swift storage as a
+# workaround.
+- name: Get Gnocchi project id
+  keystone:
+    command: get_project
+    tenant_name: "{{ gnocchi_service_project_name }}"
+    endpoint: "{{ keystone_service_adminurl }}"
+    login_user: "{{ keystone_admin_user_name }}"
+    login_password: "{{ keystone_auth_admin_password }}"
+    login_project_name: "{{ keystone_admin_tenant_name }}"
+    insecure: "{{ keystone_service_adminuri_insecure }}"
+  register: get_gnocchi_project
+  failed_when: False
+  when:
+    - swift_gnocchi_enabled | bool
+    - swift_gnocchi_service_project_id is not defined
+
+- name: Store Gnocchi project id
+  set_fact:
+    swift_gnocchi_service_project_id: "{{ keystone_facts.id }}"
+  when:
+    - swift_gnocchi_enabled | bool
+    - get_gnocchi_project | success

templates/proxy-server.conf.j2

@@ -189,5 +189,8 @@ control_exchange = swift
 driver = messagingv2
 url = rabbit://{% for host in swift_rabbitmq_telemetry_servers.split(',') %}{{ swift_rabbitmq_telemetry_userid }}:{{ swift_rabbitmq_telemetry_password }}@{{ host }}:{{ swift_rabbitmq_telemetry_port }}{% if not loop.last %},{% else %}/{{ swift_rabbitmq_telemetry_vhost }}{% endif %}{% endfor %}
 topic = notifications
+{% if swift_gnocchi_service_project_id is defined %}
+ignore_projects = "{{ swift_gnocchi_service_project_id }}""
+{% endif %}
 log_level = WARN
 {% endif %}