* elastic: fix listing against a missing or empty directory index
The refresh 404 leaked into the named return, so the first listing of a
directory whose index does not exist yet returned an error instead of an
empty result. Sorting also fails on an index with no documents
("No mapping found for [_id] in order to sort on"); unmapped_type
keeps the resumed-listing path working there.
* add elastic8 filer store for Elasticsearch 8
Elasticsearch 8 disables _id fielddata by default, so the elastic7
store's directory listings fail with "Fielddata access on the _id
field is disallowed". elastic8 uses the same client and configuration
options, but also indexes the document id as an Id field and sorts
listings on Id.keyword.
Chris LuandGitHub
2ac5aa72c7