Only Allow Enabling Streams If No Conflicting Indices Exist

[lukewhiting]

This PR makes it so that the logs streams feature can only be enabled on a cluster if there are not pre-existing indices called logs or with names starting logs.*.

Fixes ES-12416

[elasticsearchmachine]

Pinging @elastic/es-data-management (Team:Data Management)

[elasticsearchmachine]

Hi @lukewhiting, I've created a changelog YAML for you.

[Copilot]

Pull Request Overview

This PR prevents enabling logs streams when conflicting indices already exist, addressing issue ES-12416. The implementation adds validation to check for existing indices named "logs" or starting with "logs." before allowing stream enablement.

• Adds pre-validation to prevent stream enablement conflicts with existing indices
• Implements comprehensive test coverage for the new validation logic
• Exports the streams package for broader accessibility

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
server/src/main/java/module-info.java	Exports the streams package to make it accessible
modules/streams/src/yamlRestTest/resources/rest-api-spec/test/streams/logs/10_basic.yml	Adds test cases and teardown for conflict validation scenarios
modules/streams/src/main/java/org/elasticsearch/rest/streams/logs/TransportLogsStreamsToggleActivation.java	Implements the core validation logic to prevent enabling streams with conflicting indices
modules/streams/build.gradle	Minor quote style fix for consistency
docs/changelog/132064.yaml	Documents the enhancement for release notes

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