When Solr starts with embedded -DzkRun zookeeper, we currently log these lines:
2019-12-18 16:38:00.171 INFO (main) [ ] o.a.s.c.SolrZkServerProps Reading configuration from: /var/solr/data/zoo.cfg
2019-12-18 16:38:00.173 INFO (main) [ ] o.a.s.c.SolrZkServer STARTING EMBEDDED STANDALONE ZOOKEEPER SERVER at port 9983
2019-12-18 16:38:00.673 INFO (main) [ ] o.a.s.c.ZkContainer Zookeeper client=localhost:9983
In addition we should log a WARN line about not using it in production
WARN (main) [ ] o.a.s.c.SolrZkServer Embedded Zookeeper is not supported in production environments
This is already stated on the "Taking Solr to production" RefGuide page. We should also add a more prominent WARNING box to RefGuide about the same.