Add variables to manage redis url

To provide more convenience in configuring redis as Gnocchi driver,
we add 2 variables that can be used to control
URL to Redis when it's used for storage or incoming data.

Related-Bug: #1955676
Change-Id: Iba5186df3656c116cba48c3be0e39e87ddcb727f

defaults/main.yml

@@ -80,6 +80,7 @@ gnocchi_galera_port: "{{ galera_port | default('3306') }}"
 gnocchi_storage_driver: file
 gnocchi_storage_file_basepath: "{{ gnocchi_system_user_home }}"
 gnocchi_storage_swift_container_prefix: "gnocchi"
+gnocchi_storage_redis_url: "redis://localhost:6379/"
 
 gnocchi_coordination_url: "mysql://{{ gnocchi_galera_user }}:{{ gnocchi_container_mysql_password }}@{{ gnocchi_galera_address }}/{{ gnocchi_galera_database }}?charset=utf8&timeout=5{% if gnocchi_galera_use_ssl | bool %}&ssl_ca={{ gnocchi_galera_ssl_ca_cert }}{% endif %}"
 
@@ -88,6 +89,7 @@ gnocchi_coordination_url: "mysql://{{ gnocchi_galera_user }}:{{ gnocchi_containe
 gnocchi_incoming_driver: "{{ gnocchi_storage_driver }}"
 gnocchi_incoming_file_basepath: "{{ gnocchi_storage_file_basepath }}"
 gnocchi_incoming_swift_container_prefix: "{{ gnocchi_storage_swift_container_prefix }}"
+gnocchi_incoming_redis_url: "{{ gnocchi_storage_redis_url }}"
 
 #: Default Ceph parameters
 gnocchi_ceph_pool: "metrics"

releasenotes/notes/gnocchi_redis_driver-ea6bcb123755094b.yaml

@@ -0,0 +1,9 @@
+---
+features:
+  - |
+    Variables ``gnocchi_storage_redis_url`` and ``gnocchi_incoming_redis_url``
+    were added to manage redis connection if it's picked as an storage/incoming
+    driver.
+    Default value is redis://localhost:6379/
+    Please mention, that OpenStack-Ansible does not provide isntallation of
+    Redis as of today.

templates/gnocchi.conf.j2

@@ -76,6 +76,9 @@ ceph_pool = {{ gnocchi_ceph_pool }}
 # Ceph username (ie: admin without "client." prefix).
 ceph_username = {{ gnocchi_ceph_username }}
 {% endif %}
+{% if gnocchi_storage_driver == 'redis' %}
+redis_url = {{ gnocchi_storage_redis_url }}
+{% endif %}
 
 {% if gnocchi_storage_driver != gnocchi_incoming_driver %}
 [incoming]
@@ -112,6 +115,9 @@ ceph_pool = {{ gnocchi_ceph_incoming_pool }}
 # Ceph username (ie: admin without "client." prefix).
 ceph_username = {{ gnocchi_ceph_incoming_username }}
 {%   endif %}
+{%    if gnocchi_incoming_driver == 'redis' %}
+redis_url = {{ gnocchi_incoming_redis_url }}
+{%    endif %}
 {% endif %}
 
 [metricd]