caching of head requests

[willscott]

Right now, the stated plan from bifrost-gateway is that:

curl -X HEAD ipfs.io/ipfs/<cid>/path/to/data → curl -X GET saturn.tld/ipfs/<cid>/path/to/data?format=car&bytes=0:1023

• lassie expects to ignore the bytes=0:1023 range request portion of the query, so you'll end up with lassie returning (in a streaming way) the full car file of result.

• it may well be worth caching the full object at nginx - it's likely that the next request will be for most of it.

• it may be worth investigating if there's a way that's possible to do that while only returning a truncated version of the response back to the caller

[guanzo]

Should be handled by https://github.com/filecoin-saturn/nginx-car-range