On Elasticsearch, what is the required response for a directory URL of a HTTP URL repository? The official document of Elasticsearch says we can use URL as a setting of Read-only repository. The document also says several protocols, including HTTP, is supported for the URL. (refer: https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-snapshots.html#_read_only_url_repository )

I understand that the snapshots are stored in the repository as a directory structure which contains Lucene index and some meta data.

Given above conditions, I think GET request to a directory URL of a HTTP URL repository need to return a list of files/directories inside, in a certain format, for the snapshot API to restore a snapshot. At least, I thought some sort of ls operation on the directory containing Lucene indices were needed.

Questions:


Is my understanding correct?
If so, what is the required format for the directory URL? (What is the required response for HTTP request to the directory which makes snapshot API's restore work?)
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.