From 4ccf63a2ca45878e56f7de569ad65cdd427ab91f Mon Sep 17 00:00:00 2001
From: Marshall Main <marshall.main@elastic.co>
Date: Wed, 23 Jun 2021 10:49:49 -0700
Subject: [PATCH] Add empty mapping check to createOrUpdateIndexTemplate

---
 .../rule_registry/server/rule_data_client/index.ts     |  1 +
 .../server/rule_data_plugin_service/index.ts           | 10 +++++++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/x-pack/plugins/rule_registry/server/rule_data_client/index.ts b/x-pack/plugins/rule_registry/server/rule_data_client/index.ts
index fb8690c1a762d6..cb69463135ec0f 100644
--- a/x-pack/plugins/rule_registry/server/rule_data_client/index.ts
+++ b/x-pack/plugins/rule_registry/server/rule_data_client/index.ts
@@ -188,6 +188,7 @@ export class RuleDataClient implements IRuleDataClient {
     const { body: aliasExists } = await clusterClient.indices.existsAlias({
       name: alias,
     });
+
     const concreteIndexName = `${alias}-000001`;
 
     if (!aliasExists) {
diff --git a/x-pack/plugins/rule_registry/server/rule_data_plugin_service/index.ts b/x-pack/plugins/rule_registry/server/rule_data_plugin_service/index.ts
index 12609fe1c236fe..e2af6ca868795f 100644
--- a/x-pack/plugins/rule_registry/server/rule_data_plugin_service/index.ts
+++ b/x-pack/plugins/rule_registry/server/rule_data_plugin_service/index.ts
@@ -7,7 +7,7 @@
 import { ClusterPutComponentTemplate } from '@elastic/elasticsearch/api/requestParams';
 import { estypes } from '@elastic/elasticsearch';
 import { ElasticsearchClient, Logger } from 'kibana/server';
-import { merge } from 'lodash';
+import { isEmpty, merge } from 'lodash';
 import { technicalComponentTemplate } from '../../common/assets/component_templates/technical_component_template';
 import {
   DEFAULT_ILM_POLICY_ID,
@@ -132,6 +132,14 @@ export class RuleDataPluginService {
 
     const clusterClient = await this.getClusterClient();
     this.options.logger.debug(`Installing index template ${template.name}`);
+    const { body: simulateResponse } = await clusterClient.indices.simulateTemplate(template);
+    const mappings: estypes.MappingTypeMapping = simulateResponse.template.mappings;
+
+    if (isEmpty(mappings)) {
+      throw new Error(
+        'No mappings would be generated for this index, possibly due to failed/misconfigured bootstrapping'
+      );
+    }
     const mergedTemplate = merge(
       {
         body: {