Storage configuration support [storage]

[lunny]

This PR adjusted the override sequence, [storage] <- [storage.minio] <- [storage.attachments]. Right section will override left.

In fact, [storage] is expected because it's more easier to remember.

This will also enable storage tests with minio when mysql integration tests.

This also changed the behaviour of lfs serve when given a range start value out of bounds, now it will return 416, but not ignore that like before.

[techknowlogick]

TestGetLFSRange test fail with minio

[lunny]

The file tested in LFS is 10 bytes, and the request is range=11-, so the correct response of HTTP standard is to return an error or just ignore that?

The behaviour between os.File's Seek and minio's Seek is different when seek over file's size. os.File will always return no error but minio will return error with io.EOF.

[lafriks]

It should be fixed for file and minio to behave the same and handle that

[lunny]

@lafriks Yes, so which one should choose? Return io.EOF or just ignore them?

[lunny]

OK. I think https://developer.mozilla.org/en-US/docs/Web/HTTP/Range_requests explained we should return 416.

Partial request responses

There are three relevant statuses, when working with range requests:

    In case of a successful range request, the 206 Partial Content status is sent back from a server.
    In case of a range request that is out of bounds (none of the range values overlap the extent of the resource, i.e first-byte-pos of all ranges is greater than the resource length), the server responds with a 416 Requested Range Not Satisfiable status.
    In case of no support of range requests, the 200 OK status is sent back from a server.

[techknowlogick]

🚀

[techknowlogick]

@lunny please send backport :)