On Elasticsearch, what is the required response for a directory URL of a HTTP URL repository?
I also asked this question in Japanese SO and got an answer.

The snapshot, when stored, generates some files which stores the names to the data files. Namely: index, metadata-THESNAPSHOTNAME, snapshot-THESNAPSHOTNAME (note snapshot-THESNAPSHOTNAME files are generated in several directories) . From these files the relative paths of the files are generated; thus no need for ls-ing to the directory URL.

So the answer to my questions would be:


No, my assumption was wrong
No need for any response to the directory URL: URLs are constructed by following the specific file's content.