Azure: Variable editor and resource picker improvements (#101695)

* Update namespace endpoint to filter out only relevant namespaces

* Update tests

* Fix url builder tests

* Add todo comments

* Update func to use ARG to retrieve namespaces with metrics

* Refactor getMetricNamespaces for readability

* Lint

* Remove comments

* Remove type assertion

* Refactor ARG query

* Update tests and refactor class to use ARG

* Update resource group query

- Updates the resource groups query to support users/apps with restricted permissions

* Update resources request to be paginated

- Also order by name
- Add tests

* Start refactoring azure monitor util functions to resource graph

* Minor lint

* Add getMetricNamespaces resource graph function

* Modify getMetricNamespaces call

- Use resource graph function for variable queries

* Return names for getResourceNames values

* Use getMetricNamespaces variable specific req in editor

* Substantial refactor

- Update Azure Resource Graph data source with a method for making paged requests and a method for retrieving metric namespaces (and add tests)
- Extract helpers from azure_monitor_datasource to utils and generalise them (also revert previous changes to datasource and test file)
- Update mock with Azure Resource Graph data source
- Revert response parser changes
- Revert url builder changes
- Update get metric namespaces query to use the resource graph method for variable queries
- Update docs

* Lint

* Oops

* Fix type

* Lint and betterer

* Simplify imports

* Improve type

* Simplify resource picker class

* Start updating tests

* Fix naming and include missing error

* Update resource graph data source mock

* Update tests

* Remove unneeded parser

* Add get subscriptions to resource graph

* Generalise resource groups request

* Fix resource names request to ensure no clashing

* Update types

* Use resource graph queries for resource picker

* Correctly map resource group names

* Update mocks

* Update tests

* Fix mapping

* Refactor getResourceNames

- Remove most of the logic from resourcePickerData
- Add helper for parsing resource names as template vars
- Some renames for clarity
- Update types
- Update tests

* Ensure namespaces are lowercase

* Update docs/sources/datasources/azure-monitor/template-variables/index.md

Co-authored-by: Larissa Wandzura <126723338+lwandz13@users.noreply.github.com>

* Prettier write

* Ensure we return all namespaces if resourceGroup isn't specified

---------

Co-authored-by: alyssabull <alyssabull@gmail.com>
Co-authored-by: Larissa Wandzura <126723338+lwandz13@users.noreply.github.com>

public/app/plugins/datasource/azuremonitor/variables.ts

@@ -1,3 +1,4 @@
+import { startsWith } from 'lodash';
 import { from, lastValueFrom, Observable } from 'rxjs';
 
 import {
@@ -13,10 +14,26 @@ import UrlBuilder from './azure_monitor/url_builder';
 import VariableEditor from './components/VariableEditor/VariableEditor';
 import DataSource from './datasource';
 import { migrateQuery } from './grafanaTemplateVariableFns';
-import { AzureMonitorQuery, AzureQueryType } from './types';
+import { AzureMonitorQuery, AzureQueryType, RawAzureResourceItem } from './types';
 import { GrafanaTemplateVariableQuery } from './types/templateVariables';
 import messageFromError from './utils/messageFromError';
 
+export function parseResourceNamesAsTemplateVariable(resources: RawAzureResourceItem[], metricNamespace?: string) {
+  return resources.map((r) => {
+    if (startsWith(metricNamespace?.toLowerCase(), 'microsoft.storage/storageaccounts/')) {
+      return {
+        text: r.name + '/default',
+        value: r.name + '/default',
+      };
+    }
+
+    return {
+      text: r.name,
+      value: r.name,
+    };
+  });
+}
+
 export class VariableSupport extends CustomVariableSupport<DataSource, AzureMonitorQuery> {
   constructor(
     private readonly datasource: DataSource,
@@ -67,14 +84,14 @@ export class VariableSupport extends CustomVariableSupport<DataSource, AzureMoni
             return { data: [] };
           case AzureQueryType.ResourceNamesQuery:
             if (queryObj.subscription && this.hasValue(queryObj.subscription)) {
-              const rgs = await this.datasource.getResourceNames(
+              const resources = await this.datasource.getResourceNames(
                 queryObj.subscription,
                 queryObj.resourceGroup,
                 queryObj.namespace,
                 queryObj.region
               );
               return {
-                data: rgs?.length ? [toDataFrame(rgs)] : [],
+                data: resources?.length ? [toDataFrame(parseResourceNamesAsTemplateVariable(resources))] : [],
               };
             }
             return { data: [] };
@@ -201,15 +218,28 @@ export class VariableSupport extends CustomVariableSupport<DataSource, AzureMoni
     }
 
     if (query.kind === 'ResourceGroupsQuery') {
-      return this.datasource.getResourceGroups(this.replaceVariable(query.subscription));
+      return this.datasource.getResourceGroups(this.replaceVariable(query.subscription)).then((rgs) => {
+        if (rgs.length > 0) {
+          return rgs.map((rg) => ({ text: rg.resourceGroupName, value: rg.resourceGroupName }));
+        }
+
+        return [];
+      });
     }
 
     if (query.kind === 'ResourceNamesQuery') {
-      return this.datasource.getResourceNames(
-        this.replaceVariable(query.subscription),
-        this.replaceVariable(query.resourceGroup),
-        this.replaceVariable(query.metricNamespace)
-      );
+      return this.datasource
+        .getResourceNames(
+          this.replaceVariable(query.subscription),
+          this.replaceVariable(query.resourceGroup),
+          this.replaceVariable(query.metricNamespace)
+        )
+        .then((resources) => {
+          if (resources.length > 0) {
+            return parseResourceNamesAsTemplateVariable(resources, query.metricNamespace);
+          }
+          return [];
+        });
     }
 
     if (query.kind === 'MetricNamespaceQuery') {