While working on Elasticsearch debugging, I just made a docker-compose file to start up an external Elasticsearch with plugins that Liferay DXP / 7 installed with debugging tools. Hope this would be helpful for somebody working on investigation of search.
Liferay 7 GA6 / DXP fixpack 42 and onwards, Liferay uses Elasticsearch 6.1.3. According to the update, I also
has updated Elasticsearch & Kibana on docker for test / support / development use for both Oracle JDK 8 / Open JDK 8. I just divided images according to the JDK type.
The JDK must be same as Liferay server. For Oracle JDK 8, please use ${elasticsearch_version}_oraclejdk8 and for Open JDK 8, please use ${elasticsearch_version}_openjdk8 branch.
For more detailed usage, please consult to README
https://github.com/yasuflatland-lf/elasticsearch-docker-composer-for-liferay-7