From a52d6612191ff514b5889c939ed6e49c5c8c78c8 Mon Sep 17 00:00:00 2001
From: Doug Szumski <doug@stackhpc.com>
Date: Thu, 7 Jan 2021 14:01:02 +0000
Subject: [PATCH] Disable Monasca Log Metrics service by default

The Log Metrics service is an admin only service. We now have
support in Fluentd via the Prometheus plugin to create metrics
from logs. These metrics can be scraped into Monasca or Prometheus.
It therefore makes sense to deprecate this service, starting by
disabling it by default, and then removing it in the Xena release.
This should improve the stability of the Monasca metrics pipeline
by ensuring that all metrics pass via the Monasca API for
validation, and ensure that metrics generated from logs are
available to both Prometheus and Monasca users by default.

Change-Id: I704feb4434c1eece3eb00c19dc5f934fd4bc27b4
---
 ansible/roles/monasca/defaults/main.yml                |  7 ++++++-
 .../reference/logging-and-monitoring/monasca-guide.rst |  7 ++++++-
 ...e-monasca-log-metrics-service-d558015f1cf426df.yaml | 10 ++++++++++
 3 files changed, 22 insertions(+), 2 deletions(-)
 create mode 100644 releasenotes/notes/deprecate-monasca-log-metrics-service-d558015f1cf426df.yaml

diff --git a/ansible/roles/monasca/defaults/main.yml b/ansible/roles/monasca/defaults/main.yml
index ab219b832c..9ea240e01c 100644
--- a/ansible/roles/monasca/defaults/main.yml
+++ b/ansible/roles/monasca/defaults/main.yml
@@ -39,7 +39,7 @@ monasca_services:
   monasca-log-metrics:
     container_name: monasca_log_metrics
     group: monasca-log-metrics
-    enabled: true
+    enabled: "{{ monasca_enable_log_metrics_service | bool }}"
     image: "{{ monasca_logstash_image_full }}"
     volumes: "{{ monasca_log_metrics_default_volumes + monasca_log_metrics_extra_volumes }}"
     dimensions: "{{ monasca_log_metrics_dimensions }}"
@@ -125,6 +125,11 @@ monasca_influxdb_retention_policy:
 ####################
 # Monasca
 ####################
+
+# NOTE(dszumski): This can be removed in the Xena cycle when the
+# log metrics service is removed
+monasca_enable_log_metrics_service: False
+
 monasca_kafka_servers: "{% for host in groups['kafka'] %}{{ 'api' | kolla_address(host) | put_address_in_context('url') }}:{{ kafka_port }}{% if not loop.last %},{% endif %}{% endfor %}"
 monasca_zookeeper_servers: "{% for host in groups['zookeeper'] %}{{ 'api' | kolla_address(host) | put_address_in_context('url') }}:{{ zookeeper_client_port }}{% if not loop.last %},{% endif %}{% endfor %}"
 monasca_memcached_servers: "{% for host in groups['memcached'] %}{{ 'api' | kolla_address(host) | put_address_in_context('memcache') }}:{{ memcached_port }}{% if not loop.last %},{% endif %}{% endfor %}"
diff --git a/doc/source/reference/logging-and-monitoring/monasca-guide.rst b/doc/source/reference/logging-and-monitoring/monasca-guide.rst
index afd876beac..365c952c5d 100644
--- a/doc/source/reference/logging-and-monitoring/monasca-guide.rst
+++ b/doc/source/reference/logging-and-monitoring/monasca-guide.rst
@@ -329,6 +329,11 @@ which you must run the cleanup command is given below:
 
 - Upgrading from Victoria to Wallaby to remove the unused Monasca Log
   Transformer service
+- Upgrading from Victoria to Wallaby to remove the Monasca Log Metrics
+  service, unless the option to disable it by default has been overridden in
+  Wallaby.
+- Upgrading from Wallaby to Xena to remove the Monasca Log Metrics service
+  if the option to disable it by default was overridden in Wallaby.
 
 The cleanup command can be invoked from the Kolla Ansible CLI, for example:
 
@@ -371,7 +376,7 @@ Monasca will deploy the following Docker containers:
 * Monasca Agent Statsd
 * Monasca API
 * Monasca Log API
-* Monasca Log Metrics (Logstash)
+* Monasca Log Metrics (Logstash, optional, deprecated)
 * Monasca Log Persister (Logstash)
 * Monasca Notification
 * Monasca Persister
diff --git a/releasenotes/notes/deprecate-monasca-log-metrics-service-d558015f1cf426df.yaml b/releasenotes/notes/deprecate-monasca-log-metrics-service-d558015f1cf426df.yaml
new file mode 100644
index 0000000000..7ef0b0b318
--- /dev/null
+++ b/releasenotes/notes/deprecate-monasca-log-metrics-service-d558015f1cf426df.yaml
@@ -0,0 +1,10 @@
+---
+upgrade:
+  - |
+    The Monasca Log Metrics service has been deprecated and is now
+    disabled by default. If you wish to enable it, you can set
+    `monasca_enable_log_metrics_service` to `True` in `globals.yml`.
+deprecations:
+  - |
+    The Monasca Log Metrics service has been deprecated and will be
+    removed in the Xena release.