Reporting feature does not work when setting stack.templates.enabled: false in Elasticsearch

[tsullivan]

Since we have begun leveraging Elasticsearch to create a data stream for Reporting, we have begun depending on Elasticsearch to also install the mapping template for the reporting data. See #176022 and elastic/elasticsearch#97765.

Elasticsearch has a setting called stack.templates.enabled. If disabled, the mapping templates for Reporting, and other features, will not be installed.

This issue is to decide what the expected behavior is for Reporting when the setting is disabled.

[elasticmachine]

Pinging @elastic/appex-sharedux (Team:SharedUX)

[tsullivan]

Ping @dakrone The mapping templates were installed in elastic/elasticsearch#97765.

What is the typical expectation for features that depend on system mapping templates, when Elasticsearch is configured with stack.templates.enabled: false ?

[jsevidal13]

In case 01786448, the customer upgraded from 8.14 to 8.15.4, and stack.templates.enabled was set to true. They were unable to run reports because a new .kibana-reporting index kept recreating itself.

They ended up resolving the issue by deleting the .kibana-reporting index, but then ALSO had to recreate the .kibana-reporting index template. In this case, it did not get created automatically even with stack.templates.enabled set to true.

Just documenting here for reference.

[tsullivan]

We should update the documentation of Reporting requirements to state that Reporting depends on that setting to be enabled in Elasticsearch.

Likewise, we should also update documentation in https://www.elastic.co/guide/en/elasticsearch/reference/current/index-management-settings.html#stack-templates-enabled to state that modifying the setting affects Reporting's templates.

---

the customer upgraded from 8.14 to 8.15.4, and stack.templates.enabled was set to true. They were unable to run reports because a new .kibana-reporting index kept recreating itself.

We should retroactively document this change for Reporting in Kibana's changelog of releases.

---

cc @jsevidal13 @dakrone