History

Simon Hauser 618aacaa61 feat(tvix/tracing): http trace propagation Introduces a helper function within tvix-tracing that returns a reqwest tracing middleware that will ingest the traceparent if otlp is enabled. It is feature flagged in tvix-tracing so not every consumer of that library automatically has reqwest in its dependencies. Tested using netcat to verify that the `traceparent` header is there if otlp is enabled and missing if otlp feature is disabled. Change-Id: I5abccae777b725f5ff7382e3686165383c477a39 Reviewed-on: https://cl.tvl.fyi/c/depot/+/11886 Tested-by: BuildkiteCI Reviewed-by: flokli <flokli@flokli.de>		2024-07-02 13:43:09 +00:00
..
protos	refactor(tvix/*/protos): separate lint target	2023-12-11 22:35:39 +00:00
src	feat(tvix/tracing): http trace propagation	2024-07-02 13:43:09 +00:00
build.rs	fix(tvix): don't emit rerun-if-changed	2024-03-16 09:34:10 +00:00
Cargo.toml	feat(tvix/tracing): http trace propagation	2024-07-02 13:43:09 +00:00
default.nix	chore(tvix/docs): move [ca]store docs to tvix/docs	2024-06-14 08:00:34 +00:00
README.md	fix(tvix/store): rename Read method in Readme	2023-09-26 15:24:32 +00:00

README.md

//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.