dashboard: set InfluxDB measurement dynamically

After this patch, user may choose InfluxDB measurement from the list of
measurements with Tarantool metrics instead of manually setting up
a constant measurement on import.

Part of #185

Author: DifferentialOrange

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 - Replace LuaJit deprecated metrics with new ones
 - Set Prometheus `job` dynamically
+- Set InfluxDB `measurement` dynamically
 
 
 ## [1.5.0] - 2022-09-22

README.md

@@ -46,11 +46,11 @@ Refer to dashboard [documentation page](https://www.tarantool.io/en/doc/latest/b
 
     You need to set the following variables for InfluxDB datasource:
 
-    - `Measurement`,
     - `Policy` (default valie is `autogen`).
 
     Datasource variables can be obtained from your datasource configuration.
     You can choose `job` variable value for Prometheus datasource after import.
+    You can choose `measurement` variable value for InfluxDB datasource after import.
     Variables for example monitoring cluster are described in [Monitoring cluster](#monitoring-cluster) section.
 
 
@@ -72,7 +72,6 @@ You can also interact with Prometheus at [localhost:9090](http://localhost:9090/
 
 To set up an InfluxDB dashboard for monitoring example app, use the following variables:
 
-- `Measurement`: `tarantool_http`;
 - `Policy`: `default`.
 
 ### Monitoring local app

dashboard/build/influxdb/dashboard.libsonnet

@@ -15,18 +15,20 @@ dashboard_raw(
   pluginId='influxdb',
   pluginName='InfluxDB',
   description='InfluxDB Tarantool metrics bank'
-).addInput(
-  name='INFLUXDB_MEASUREMENT',
-  label='Measurement',
-  type='constant',
-  value='tarantool_http',
-  description='InfluxDB Tarantool metrics measurement'
 ).addInput(
   name='INFLUXDB_POLICY',
   label='Policy',
   type='constant',
   value='autogen',
   description='InfluxDB Tarantool metrics policy'
+).addTemplate(
+  grafana.template.new(
+    name='measurement',
+    datasource=variable.datasource.influxdb,
+    query=std.format('SHOW MEASUREMENTS WHERE "metric_name"=\'%s\'', variable.metrics.tarantool_indicator),
+    label='Measurement',
+    refresh='load',
+  )
 ).addTemplate(
   grafana.template.new(
     name='alias',

dashboard/build/influxdb/tdg_dashboard.libsonnet

@@ -15,18 +15,20 @@ tdg_dashboard_raw(
   pluginId='influxdb',
   pluginName='InfluxDB',
   description='InfluxDB Tarantool metrics bank'
-).addInput(
-  name='INFLUXDB_MEASUREMENT',
-  label='Measurement',
-  type='constant',
-  value='tarantool_http',
-  description='InfluxDB Tarantool metrics measurement'
 ).addInput(
   name='INFLUXDB_POLICY',
   label='Policy',
   type='constant',
   value='autogen',
   description='InfluxDB Tarantool metrics policy'
+).addTemplate(
+  grafana.template.new(
+    name='measurement',
+    datasource=variable.datasource.influxdb,
+    query=std.format('SHOW MEASUREMENTS WHERE "metric_name"=\'%s\'', variable.metrics.tarantool_indicator),
+    label='Measurement',
+    refresh='load',
+  )
 ).addTemplate(
   grafana.template.new(
     name='alias',

dashboard/variable.libsonnet

@@ -13,7 +13,7 @@
   },
   influxdb: {
     policy: '${INFLUXDB_POLICY}',
-    measurement: '${INFLUXDB_MEASUREMENT}',
+    measurement: '$measurement',
     alias: '/^$alias$/',
   },
   metrics: {

doc/monitoring/grafana_dashboard.rst

@@ -208,7 +208,7 @@ To import a specific dashboard, choose one of the following options:
 - upload the dashboard JSON file.
 
 Set dashboard name, folder, uid (if needed), and datasource-related query parameters
-(InfluxDB source, measurement and policy or Prometheus source).
+(InfluxDB source and policy or Prometheus source).
 
 ..  image:: images/grafana_import_setup.png
     :align: left