Support Prometheus as metrics database for Ceilometer

This commit adds support for pushing Ceilometer metrics
to Prometheus instead of Gnocchi or alongside it.


Closes-Bug: #1964135
Signed-off-by: Juan Pablo Suazo <jsuazo@whitestack.com>
Change-Id: I9fd32f63913a534c59e2d17703702074eea5dd76

ansible/group_vars/all.yml

@@ -605,6 +605,7 @@ enable_barbican: "no"
 enable_blazar: "no"
 enable_ceilometer: "no"
 enable_ceilometer_ipmi: "no"
+enable_ceilometer_prometheus_pushgateway: "no"
 enable_cells: "no"
 enable_central_logging: "no"
 enable_ceph_rgw: "no"

ansible/roles/ceilometer/defaults/main.yml

@@ -182,6 +182,12 @@ ceilometer_ks_users:
 # Backend
 ####################
 
-ceilometer_database_type: "gnocchi"
+ceilometer_database_type: "{{ 'gnocchi' if (enable_gnocchi | bool) else '' }}"
 
 ceilometer_upgrade_params: ""
+
+####################
+# Pushgateway
+####################
+ceilometer_prometheus_pushgateway_host: "127.0.0.1"
+ceilometer_prometheus_pushgateway_port: "9091"

ansible/roles/ceilometer/tasks/precheck.yml

@@ -12,4 +12,4 @@
   changed_when: false
   when:
     - enable_ceilometer | bool
-    - not enable_gnocchi | bool
+    - not (enable_gnocchi | bool or enable_ceilometer_prometheus_pushgateway | bool)

ansible/roles/ceilometer/templates/pipeline.yaml.j2

@@ -8,4 +8,9 @@ sources:
 sinks:
     - name: meter_sink
       publishers:
+{% if enable_gnocchi | bool %}
           - gnocchi://
+{% endif %}
+{% if enable_ceilometer_prometheus_pushgateway | bool %}
+          - prometheus://{{ ceilometer_prometheus_pushgateway_host }}:{{ ceilometer_prometheus_pushgateway_port }}/metrics/job/openstack-telemetry
+{% endif %}

releasenotes/notes/bug-1964135-383c8bf4fad16618.yaml

@@ -0,0 +1,8 @@
+---
+features:
+  - |
+    Adds the ability to use Prometheus as the metrics database for Ceilometer.
+
+    Adapts Ceilometer configurations so metrics can be pushed to a Prometheus
+    Pushgateway.
+    `LP#1964135 <https://bugs.launchpad.net/kolla-ansible/+bug/1964135>`__