Feature #14199

Updated by Peter Amstutz 9 months ago

API to instruct keepstore to fetch a remote block, save it, and return signed locator (variation on "proxy a
block read request" with the added feature of saving the block).

(Is this triggered by a query flag? Basically an explicit "cache block" operation)

Proposed API:

Do a HEAD request (equivalent to the GET request) on remote signed locator and look for a response header that has a new locator with local block signature. This header should be called "X-Keep-Locator" (?).

All keepstore GET and HEAD responses for block requests should include this new header.