Switch default cloudkitty storage backend to influxdb

Backport: stein

In the Stein release, cloudkitty switched the default storage backend
from sqlalchemy to influxdb. In kolla-ansible stein configuration, we
did not explicitly set the storage backend, and so we automatically
picked up this change. However, prior to
https://review.opendev.org/#/c/615928/ we did not have full support for
InfluxDB as a storage backend, and so this has broken the Rocky-Stein
upgrade (https://bugs.launchpad.net/kolla-ansible/+bug/1838641), which
fails with this during the DB sync:

ERROR cloudkitty InfluxDBClientError: get_list_retention_policies()
requires a database as a parameter or the client to be using a database

This change synchronises our default with cloudkitty's (influxdb), and
also provides an upgrade transition to create the influxdb database.

We also move the cloudkitty_storage_backend variable to
group_vars/all.yml, since it is used to determine whether to enable
influxdb.

Finally, the section name in cloudkitty.conf was incorrect - it was
storage_influx,  but should be storage_influxdb.

Change-Id: I71f2ed11bd06f58e141d222e2709835b7ddb2c71
Closes-Bug: #1838641

ansible/group_vars/all.yml

@@ -597,7 +597,7 @@ enable_horizon_vitrage: "{{ enable_vitrage | bool }}"
 enable_horizon_watcher: "{{ enable_watcher | bool }}"
 enable_horizon_zun: "{{ enable_zun | bool }}"
 enable_hyperv: "no"
-enable_influxdb: "{{ enable_monasca | bool or (cloudkitty_storage_backend is defined and cloudkitty_storage_backend == 'influxdb') }}"
+enable_influxdb: "{{ enable_monasca | bool or (enable_cloudkitty | bool and cloudkitty_storage_backend == 'influxdb') }}"
 enable_ironic: "no"
 enable_ironic_ipxe: "no"
 enable_ironic_neutron_agent: "{{ enable_neutron | bool and enable_ironic | bool }}"
@@ -861,6 +861,12 @@ cinder_backup_mount_options_nfs: ""
 #######################
 # Valid option is gnocchi
 cloudkitty_collector_backend: "gnocchi"
+# Valid options are 'sqlalchemy' or 'influxdb'. The default value is
+# 'influxdb', which matches the default in Cloudkitty since the Stein release.
+# When the backend is "influxdb", we also enable Influxdb.
+# Also, when using 'influxdb' as the backend, we trigger the configuration/use
+# of Cloudkitty storage backend version 2.
+cloudkitty_storage_backend: "influxdb"
 
 #######################
 # Designate options

ansible/roles/cloudkitty/defaults/main.yml

@@ -100,13 +100,12 @@ cloudkitty_custom_metrics_yaml_file: "metrics.yml"
 ####################
 # Storage backend
 ####################
-# Valid options are 'sqlalchemy' or 'influxdb'. The default value in
-# Kolla-ansible is 'sqlalchemy' (for backwards compatibility).
-# When cloudkitty_storage_backend is define with "influxdb" as its value,
-# we also trigger the deployment of Influxdb via Kolla-ansible.
+# Valid options are 'sqlalchemy' or 'influxdb'. The default value is
+# 'influxdb', which matches the default in Cloudkitty since the Stein release.
+# When the backend is "influxdb", we also enable Influxdb.
 # Also, when using 'influxdb' as the backend, we trigger the configuration/use
 # of Cloudkitty storage backend version 2.
-cloudkitty_storage_backend: "sqlalchemy"
+cloudkitty_storage_backend: "influxdb"
 
 # InfluxDB retention policy to use (defaults to autogen).
 # cloudkitty_influxdb_retention_policy: "autogen"

ansible/roles/cloudkitty/tasks/upgrade.yml

@@ -1,6 +1,19 @@
 ---
 - include_tasks: config.yml
 
+# NOTE(mgoddard): Transition support for upgrades from Rocky or Stein which may
+# be using the SQLAlchemy storage backend.
+# TODO(mgoddard): Remove in U cycle.
+- name: Creating Cloudkitty influxdb database
+  become: true
+  kolla_toolbox:
+    module_name: influxdb_database
+    module_args:
+      hostname: "{{ influxdb_address }}"
+      port: "{{ influxdb_http_port }}"
+      database_name: "{{ cloudkitty_influxdb_name }}"
+  when: cloudkitty_storage_backend == 'influxdb'
+
 - include_tasks: bootstrap_service.yml
 
 - name: Flush handlers

ansible/roles/cloudkitty/templates/cloudkitty.conf.j2

@@ -72,7 +72,7 @@ version = 1
 {% endif %}
 
 {% if cloudkitty_storage_backend == 'influxdb' %}
-[storage_influx]
+[storage_influxdb]
 database = {{ cloudkitty_influxdb_name }}
 host = {{ influxdb_address }}
 port = {{ influxdb_http_port }}

etc/kolla/globals.yml

@@ -268,7 +268,7 @@
 #enable_horizon_watcher: "{{ enable_watcher | bool }}"
 #enable_horizon_zun: "{{ enable_zun | bool }}"
 #enable_hyperv: "no"
-#enable_influxdb: "{{ enable_monasca | bool or (cloudkitty_storage_backend is defined and cloudkitty_storage_backend == 'influxdb') }}"
+#enable_influxdb: "{{ enable_monasca | bool or (enable_cloudkitty | bool and cloudkitty_storage_backend == 'influxdb') }}"
 #enable_ironic: "no"
 #enable_ironic_ipxe: "no"
 #enable_ironic_neutron_agent: "{{ enable_neutron | bool and enable_ironic | bool }}"
@@ -446,6 +446,17 @@
 #cinder_backup_share: ""
 #cinder_backup_mount_options_nfs: ""
 
+#######################
+# Cloudkitty options
+#######################
+# Valid option is gnocchi
+#cloudkitty_collector_backend: "gnocchi"
+# Valid options are 'sqlalchemy' or 'influxdb'. The default value is
+# 'influxdb', which matches the default in Cloudkitty since the Stein release.
+# When the backend is "influxdb", we also enable Influxdb.
+# Also, when using 'influxdb' as the backend, we trigger the configuration/use
+# of Cloudkitty storage backend version 2.
+#cloudkitty_storage_backend: "influxdb"
 
 ###################
 # Designate options

releasenotes/notes/cloudkitty-default-influxdb-397d7441ad2576c5.yaml

@@ -0,0 +1,8 @@
+---
+upgrade:
+  - |
+    Modifies the default storage backend for Cloudkitty to InfluxDB, to match
+    the default in Cloudkitty from Stein onwards. This is controlled via
+    ``cloudkitty_storage_backend``. To use the previous default, set
+    ``cloudkitty_storage_backend`` to ``sqlalchemy``. See `bug 1838641
+    <https://bugs.launchpad.net/kolla-ansible/+bug/1838641>`__ for details.