Add docs for configuring CloudKitty

doc/source/configuration/cloudkitty.rst

@@ -0,0 +1,141 @@
+==========
+CloudKitty
+==========
+
+Configuring in kayobe-config
+============================
+
+By default, CloudKitty uses Gnocchi and Ceilometer as the collector and fetcher
+backends. Unless the system has a specific reason not to, we recommend instead
+using Prometheus as the backend for both. The following instructions explain
+how to do this. Also, see the `Kolla Ansible docs on CloudKitty
+<https://docs.openstack.org/kolla-ansible/latest/reference/rating/cloudkitty-guide.html>`__
+for more details.
+
+Enable CloudKitty and disable InfluxDB, as we are using OpenSearch as the
+storage backend. Set the following in ``kolla.yml``:
+
+.. code-block:: yaml
+
+  kolla_enable_cloudkitty: true
+  # Explicitly disable influxdb as we are using OpenSearch as the CloudKitty backend
+  kolla_enable_influxdb: false
+
+Set Prometheus as the backend for both the collector and fetcher, and
+Elasticsearch as the storage backend. Note that our fork of CloudKitty is
+patched so that the CloudKitty Elasticsearch V2 storage backend will also work
+with an OpenSearch cluster. Proper support for the V2 OpenSearch storage
+backend is still pending in Kolla-Ansible `here
+<https://review.opendev.org/c/openstack/kolla-ansible/+/898555>`__. Set the
+following in ``kolla/globals.yml``:
+
+.. code-block:: yaml
+
+  cloudkitty_collector_backend: prometheus
+  cloudkitty_fetcher_backend: prometheus
+  cloudkitty_storage_backend: elasticsearch
+
+If you have TLS enabled, you will also need to set the cafile for Prometheus
+and Elasticsearch. Set the following in ``kolla/globals.yml``.
+
+.. code-block::
+
+  {% raw %}
+  cloudkitty_prometheus_cafile: "{{ openstack_cacert }}"
+  cloudkitty_elasticsearch_cafile: "{{ openstack_cacert }}"
+  {% endraw %}
+
+The default collection period is one hour, which is likely too long for most
+systems as CloudKitty charges by the **entire** collection period if any usage
+is seen within this timeframe. This is regardless of actual usage, meaning that
+even one minute will be charged as a full hour's usage. As a result, it is
+recommended to adjust the collection interval, ``period`` (in units of
+seconds), appropriately (e.g. ten minutes). Furthermore, when using Prometheus
+as the collector, you need to change the ``scope_key`` to match the metrics
+provided by the Prometheus OpenStack Exporter. Both of these can be achieved by
+setting the following in ``kolla/config/cloudkitty.conf``:
+
+.. code-block:: console
+
+  [collect]
+  scope_key = tenant_id
+  period = 600
+
+You will need to configure which metrics CloudKitty should track. The following
+example, set in ``kolla/config/cloudkitty/metrics.yml``, will track for VM flavors and
+the total utilised volume.
+
+.. code-block:: yaml
+
+  metrics:
+    openstack_nova_server_status:
+      alt_name: instance
+      groupby:
+        - uuid
+        - user_id
+        - tenant_id
+      metadata:
+        - flavor_id
+        - name
+      mutate: MAP
+      mutate_map:
+        0.0: 1.0  # ACTIVE
+        11.0: 1.0 # SHUTOFF
+        12.0: 1.0 # SUSPENDED
+        16.0: 1.0 # PAUSED
+      unit: instance
+    openstack_cinder_limits_volume_used_gb:
+      alt_name: storage
+      unit: GiB
+      groupby:
+        - tenant_id
+
+If your system had Monasca deployed in the past, you likely have some
+relabelled attributes in the Prometheus OpenStack exporter. To account for
+this, you should either remove the custom relabelling (in
+``kolla/config/prometheus.yml``) or change your ``metrics.yml`` to use the
+correct attributes.
+
+Post-configuration with openstack-config
+========================================
+
+This is an example `openstack-config
+<https://github.com/stackhpc/openstack-config>`__ setup to create mappings for
+the metrics configured above. Note that the costs are scaled for the ten minute
+collection period, e.g. a flavor with 1 VCPU will cost 1 unit per hour.
+
+.. code-block:: yaml
+
+  # Map flavors based on VCPUs
+  openstack_ratings_hashmap_field_mappings:
+    - service: instance
+      name: flavor_id
+      mappings:
+      - value: '1' # tiny compute flavor (1 vcpu) with an OpenStack flavor ID of 1
+        cost: 0.1666666666666666
+        type: flat
+      - value: '2' # small compute flavor (2 vcpus) with an OpenStack flavor ID of 2
+        cost: 0.3333333333333333
+        type: flat
+      - value: '3' # medium compute flavor (3 vcpus) with an OpenStack flavor ID of 3
+        cost: 0.5
+        type: flat
+      - value: '4' # large compute flavor (4 vcpus) with an OpenStack flavor ID of 4
+        cost: 0.6666666666666666
+        type: flat
+      - value: '5' # xlarge compute flavor (8 vcpus) with an OpenStack flavor ID of 5
+        cost: 1.3333333333333333
+        type: flat
+      - value: '6' # tiny 2 compute flavor (2 vcpus) with an OpenStack flavor ID of 6
+        cost: 0.3333333333333333
+        type: flat
+
+  # Map volumes based on GB
+  openstack_ratings_hashmap_service_mappings:
+    - service: storage
+      cost: 0.16666666666666666
+      type: flat
+
+See the `OpenStack CloudKitty Ratings role
+<https://github.com/stackhpc/ansible-collection-openstack/tree/main/roles/os_ratings>`__
+for more details.

doc/source/configuration/index.rst

@@ -20,3 +20,4 @@ the various features provided.
    magnum-capi
    ci-cd
    security-hardening
+   cloudkitty