[APM\ Update index template names considered in the diagnostics page (#184343)

closes [#184333](https://github.com/elastic/kibana/issues/184333)

## Summary

This PR updates the index template names that the diagnostics page
verifies the existence of.

After the changes made in the [APM
package](https://github.com/elastic/integrations/pull/9949), to favor
APM indices and ingest pipelines configured by elasticsearch, the index
templates now have a `@template` suffix. eg:
`metrics-apm.service_destination.1m` is now
`metrics-apm.service_destination.1m@template`

<img width="709" alt="image"
src="4608da37-679a-411c-85c4-409b2af62cec">

<img width="709" alt="image"
src="837c8ae0-2c92-4763-811c-22fc619ba5f6">

**When no indices are found**
<img width="709" alt="image"
src="33d7264a-dc90-49a0-a3f4-f169dcbda861">


### How to test

- Start a local ES and kibana instance
- navigate to
`/apm/diagnostics/index-templates?rangeFrom=now-15m&rangeTo=now`

---------

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>

x-pack/plugins/observability_solution/apm/server/routes/diagnostics/bundle/get_existing_index_templates.ts

@@ -19,10 +19,12 @@ export async function getExistingApmIndexTemplates({
 }) {
   const apmIndexTemplateNames = getApmIndexTemplateNames();
   const values = await Promise.all(
-    apmIndexTemplateNames.map(async (indexTemplateName) => {
-      const res = await getIndexTemplate(esClient, { name: indexTemplateName });
-      return res.index_templates[0];
-    })
+    Object.values(apmIndexTemplateNames)
+      .flat()
+      .map(async (indexTemplateName) => {
+        const res = await getIndexTemplate(esClient, { name: indexTemplateName });
+        return res.index_templates[0];
+      })
   );
 
   return values.filter((v) => v !== undefined);

x-pack/plugins/observability_solution/apm/server/routes/diagnostics/bundle/get_index_templates_by_index_pattern.ts

@@ -79,12 +79,13 @@ async function getTemplatePriority(esClient: ElasticsearchClient, name: string)
 function getIsNonStandardIndexTemplate(templateName: string) {
   const apmIndexTemplateNames = getApmIndexTemplateNames();
   const stackIndexTemplateNames = ['logs', 'metrics'];
-  const isNonStandard = [...apmIndexTemplateNames, ...stackIndexTemplateNames].every(
-    (apmIndexTemplateName) => {
-      const notMatch = templateName !== apmIndexTemplateName;
-      return notMatch;
-    }
-  );
+  const isNonStandard = [
+    ...Object.values(apmIndexTemplateNames).flat(),
+    ...stackIndexTemplateNames,
+  ].every((apmIndexTemplateName) => {
+    const notMatch = templateName !== apmIndexTemplateName;
+    return notMatch;
+  });
 
   return isNonStandard;
 }

x-pack/plugins/observability_solution/apm/server/routes/diagnostics/bundle/get_indices_states.ts

@@ -85,8 +85,10 @@ export function validateIngestPipelineName(
   }
 
   const indexTemplateNames = getApmIndexTemplateNames();
-  return indexTemplateNames.some(
-    (indexTemplateName) =>
-      dataStream.startsWith(indexTemplateName) && ingestPipelineId.startsWith(indexTemplateName)
-  );
+  return Object.values(indexTemplateNames)
+    .flat()
+    .some(
+      (indexTemplateName) =>
+        dataStream.startsWith(indexTemplateName) && ingestPipelineId.startsWith(indexTemplateName)
+    );
 }

x-pack/plugins/observability_solution/apm/server/routes/diagnostics/helpers/get_apm_index_template_names.ts

@@ -7,6 +7,7 @@
 
 import { IndicesGetIndexTemplateIndexTemplateItem } from '@elastic/elasticsearch/lib/api/types';
 
+const suffix = 'template';
 export function getApmIndexTemplateNames() {
   const indexTemplateNames = [
     'logs-apm.app',
@@ -27,22 +28,30 @@ export function getApmIndexTemplateNames() {
     ].map((ds) => `${ds}.${interval}`);
   });
 
-  return [...indexTemplateNames, ...rollupIndexTemplateNames];
+  // For retrocompatibility, it returns index template names both pre and post APM integration package v8.15.0
+  return [...indexTemplateNames, ...rollupIndexTemplateNames].reduce((acc, indexTemplateName) => {
+    acc[indexTemplateName] = [indexTemplateName, `${indexTemplateName}@${suffix}`];
+    return acc;
+  }, {} as Record<string, string[]>);
 }
 
 export function getApmIndexTemplates(
   existingIndexTemplates: IndicesGetIndexTemplateIndexTemplateItem[]
 ) {
   const apmIndexTemplateNames = getApmIndexTemplateNames();
-  const standardIndexTemplates = apmIndexTemplateNames.map((templateName) => {
-    const matchingTemplate = existingIndexTemplates.find(({ name }) => name === templateName);
+  const standardIndexTemplates = Object.entries(apmIndexTemplateNames).map(
+    ([baseTemplateName, validIndexTemplateNames]) => {
+      const matchingTemplate = validIndexTemplateNames.find((templateName) =>
+        existingIndexTemplates.find(({ name }) => name === templateName)
+      );
 
-    return {
-      name: templateName,
-      exists: Boolean(matchingTemplate),
-      isNonStandard: false,
-    };
-  });
+      return {
+        name: matchingTemplate ?? baseTemplateName,
+        exists: Boolean(matchingTemplate),
+        isNonStandard: false,
+      };
+    }
+  );
 
   const nonStandardIndexTemplates = existingIndexTemplates
     .filter(

x-pack/test/apm_api_integration/tests/diagnostics/index_pattern_settings.ts

@@ -24,7 +24,9 @@ export default function ApiTest({ getService }: FtrProviderContext) {
     describe('When there is no data', () => {
       before(async () => {
         // delete APM index templates
-        await es.indices.deleteIndexTemplate({ name: getApmIndexTemplateNames() });
+        await es.indices.deleteIndexTemplate({
+          name: Object.values(getApmIndexTemplateNames()).flat(),
+        });
       });
 
       it('returns the built-in (non-APM) index templates`', async () => {

x-pack/test/apm_api_integration/tests/diagnostics/index_templates.spec.ts

@@ -24,7 +24,9 @@ export default function ApiTest({ getService }: FtrProviderContext) {
     describe('When there is no data', () => {
       before(async () => {
         // delete APM index templates
-        await es.indices.deleteIndexTemplate({ name: getApmIndexTemplateNames() });
+        await es.indices.deleteIndexTemplate({
+          name: Object.values(getApmIndexTemplateNames()).flat(),
+        });
       });
 
       it('verifies that none of the default APM index templates exists`', async () => {