tvl-depot/tvix/store
Florian Klink 7e8719be91 feat(tvix/store/pathinfosvc/nix_http): check Nar{Size,Hash} matches
Ensure the initially communicated NarHash/NarSize from the NarInfo
matches what we read, and don't return a PathInfo message if there's
a mismatch.

Also move the buffering layer around a bit.

Change-Id: I68c60ecfaf0f9cd5edacea648437ecb0c9729251
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10148
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-11-28 16:08:59 +00:00
..
docs chore(tvix/castore): move data model docs to here 2023-11-02 09:08:20 +00:00
protos feat(tvix/store/protos): add CA field 2023-10-22 17:04:37 +00:00
src feat(tvix/store/pathinfosvc/nix_http): check Nar{Size,Hash} matches 2023-11-28 16:08:59 +00:00
build.rs chore(tvix/[ca]store): allow building without tonic-reflection 2023-09-26 10:07:40 +00:00
Cargo.toml feat(tvix/store/pathinfoservice): implement NixHTTPPathInfoService 2023-11-19 13:19:24 +00:00
default.nix fix(tvix/store): Remove virtiofs from default features 2023-10-07 02:34:00 +00:00
README.md fix(tvix/store): rename Read method in Readme 2023-09-26 15:24:32 +00:00

//tvix/store

This contains the code hosting the tvix-store.

For the local store, Nix realizes files on the filesystem in /nix/store (and maintains some metadata in a SQLite database). For "remote stores", it communicates this metadata in NAR (Nix ARchive) and NARInfo format.

Compared to the Nix model, tvix-store stores data on a much more granular level than that, which provides more deduplication possibilities, and more granular copying.

However, enough information is preserved to still be able to render NAR and NARInfo when needed.

More Information

The store consists out of two different gRPC services, tvix.castore.v1 for the low-level content-addressed bits, and tvix.store.v1 for the Nix and StorePath-specific bits.

Check the protos/ subfolder both here and in castore for the definition of the exact RPC methods and messages.

Interacting with the GRPC service manually

The shell environment in //tvix provides evans, which is an interactive REPL-based gPRC client.

You can use it to connect to a tvix-store and call the various RPC methods.

$ cargo run -- daemon &
$ evans --host localhost --port 8000 -r repl
  ______
 |  ____|
 | |__    __   __   __ _   _ __    ___
 |  __|   \ \ / /  / _. | | '_ \  / __|
 | |____   \ V /  | (_| | | | | | \__ \
 |______|   \_/    \__,_| |_| |_| |___/

 more expressive universal gRPC client


localhost:8000> package tvix.castore.v1
tvix.castore.v1@localhost:8000> service BlobService

tvix.castore.v1.BlobService@localhost:8000> call Put --bytes-from-file
data (TYPE_BYTES) => /run/current-system/system
{
  "digest": "KOM3/IHEx7YfInAnlJpAElYezq0Sxn9fRz7xuClwNfA="
}

tvix.castore.v1.BlobService@localhost:8000> call Read --bytes-as-base64
digest (TYPE_BYTES) => KOM3/IHEx7YfInAnlJpAElYezq0Sxn9fRz7xuClwNfA=
{
  "data": "eDg2XzY0LWxpbnV4"
}

$ echo eDg2XzY0LWxpbnV4 | base64 -d
x86_64-linux

Thanks to tvix-store providing gRPC Server Reflection (with reflection feature), you don't need to point evans to the .proto files.