Getting health status fails for non system users

I'm using Hibernate Search ORM with Elastic Search on http://www.euregjug.eu.

After upgrading from 5.6 beta to 5.8 (see https://github.com/EuregJUG-Maas-Rhine/site/commit/70099d231f05810376fd8f86783b75fd01a6b11c), the application fails to start because it cannot get the health for the index from the http://www.searchly.com elastic search instance.

It tries to retrieve "/_cluster/health/eu.euregjug.site.posts.postentity/" which fails:

Status: 500 Internal Server Error:

Error message: {"root_cause":[{"type":"exception","reason":"Requested resource only accessible by admin or system users"}],"type":"exception","reason":"Requested resource only accessible by admin or system users"}

The problem here is the forward slash at the end of the index name. If I remove that and CURL the full URL including the same username I configured for Hibernate Search, it works.

As I use the auto generated index name, there's a little I can do as an end developer here.