Currently path value on cluster.search -> host must point to existing index only but not an alias.
Configuring it as an alias works for indexing and search, but cluster statistics can not be viewed and Call to a member function hasAnyProperties() on boolean error is thrown.
Error is thrown because Phabricator can not find the index with given name.
To fix this it would be required perform additional query to elastichost/_aliases if index is not found. And then retrieve original index name from the alias.
@epriestley Let me know if you think this needs to be supported on upstream and I can provide a patch. Thanks!