Upload and download data from and to volumes

[PizieDust]

closes #93 #92 #32

This PR adds the functionality to download data and upload data to and from block devices.
There's also some refactoring for modals where all is moved to a single component, same with buttons.

At the moment, we can't download a volume if it is in use by a running unikernel, we also can't upload data to a volume which is in use by a running unikernel.

[PizieDust]

@hannesm I don't know if this is intended but uploads which are larger in size than the volume are successful. For example uploading a 5MB file to a 1MB volume is successful. I don't know if this should be the case.
also, empty uploads are successful (uploads with no file).

[hannesm]

Thanks for refining the error message. Now, I'd appreciate if the deployUnikernel() as well gets such nice informative error messages, and best have both share the code....

So, could "isValidName" return the error message?

[hannesm]

Thanks for your PR:

@hannesm I don't know if this is intended but uploads which are larger in size than the volume are successful. For example uploading a 5MB file to a 1MB volume is successful.

This is strange, from the albatross source:

  | `Block_set (compressed, data) ->
    begin match Vmm_resources.find_block t.resources id with
      | None -> Error (`Msg "set block: not found")
      | Some (_, true) -> Error (`Msg "set block: is in use")
      | Some (size, false) ->
        let* data =
          if compressed then
            Vmm_compress.uncompress data
          else
            Ok data
        in
        let* size_in_bytes = Vmm_unix.bytes_of_mb size in
        let* () =
          if size_in_bytes >= String.length data then
            Ok ()
          else
            Error (`Msg "data exceeds block size")
        in
        let* () = Vmm_unix.destroy_block id in
        let* () = Vmm_unix.create_block ~data id size in
        Ok (t, `End (`Success (`String "set block device")))
    end

So, we first lookup the block name in the resources, which returns us a size (in MB), then we compare that this size (converted to bytes) is greater or equal to the length of the uncompressed data (String.length data). Does, when you uploaded a 5 MB data blob to a 1 MB block device the device size increase to 5 MB? was all data written?

I don't know if this should be the case. also, empty uploads are successful (uploads with no file).

I don't know exactly what you mean here. So, if albatross receives a "Block_set" with an empty string, it writes all 0s to the block device (which is always truncated to the size that was specified when it was created).

What does mollymawk emit to albatross in the case of "uploads with no file"?

[PizieDust]

Both cases emit "set block device" which is a success response. When I upload a larger file, there's no way to tell how many bytes get uploaded.

…

On Wed, 20 Nov 2024, 18:53 Hannes Mehnert, ***@***.***> wrote: Thanks for your PR: @hannesm <https://github.com/hannesm> I don't know if this is intended but uploads which are larger in size than the volume are successful. For example uploading a 5MB file to a 1MB volume is successful. This is strange, from the albatross source: | `Block_set (compressed, data) -> begin match Vmm_resources.find_block t.resources id with | None -> Error (`Msg "set block: not found") | Some (_, true) -> Error (`Msg "set block: is in use") | Some (size, false) -> let* data = if compressed then Vmm_compress.uncompress data else Ok data in let* size_in_bytes = Vmm_unix.bytes_of_mb size in let* () = if size_in_bytes >= String.length data then Ok () else Error (`Msg "data exceeds block size") in let* () = Vmm_unix.destroy_block id in let* () = Vmm_unix.create_block ~data id size in Ok (t, `End (`Success (`String "set block device"))) end So, we first lookup the block name in the resources, which returns us a size (in MB), then we compare that this size (converted to bytes) is greater or equal to the length of the uncompressed data (String.length data). Does, when you uploaded a 5 MB data blob to a 1 MB block device the device size increase to 5 MB? was all data written? I don't know if this should be the case. also, empty uploads are successful (uploads with no file). I don't know exactly what you mean here. So, if albatross receives a "Block_set" with an empty string, it writes all 0s to the block device (which is always truncated to the size that was specified when it was created). What does mollymawk emit to albatross in the case of "uploads with no file"? — Reply to this email directly, view it on GitHub <#95 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A2VKJEUQZOJLFBY3RTF5RN32BTECVAVCNFSM6AAAAABSFBG46KVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDIOBZGIZDCMZYGI> . You are receiving this because you were assigned.Message ID: ***@***.***>

[hannesm]

here we need a different interface for albatross, and have some streaming or chunk read & write - likely with a chunked transfer-encoding.

[hannesm]

similar to unikernel_deploy, we should (at one day in our live) have a streaming interface here as well, instead of requiring the entire data fitting into memory.

the downside (and we'll likely need to revise the protocol) is that in TLS we can embed only 16MB of certificates, this means that we can't write/set multi-gigabyte block devices. for now, this is a shortcoming -- I opened an issue at the albatross repository robur-coop/albatross#201

[hannesm]

Thanks, let's address suggestions in subsequent PRs