6815572274
To support tvix builds, we need to be able to use the `TvixStoreFs` to materialize the sandbox's /nix/store filesystem with just the list of inputs needed for the build. Currently we'd need to seed an in-memory `PathInfoService`, which includes more functionality than what is required for `TvixStoreFs`. Additionally, the `PathInfoService` is specific to Nix. By decoupling `TvixStoreFs` and `PathInfoService`, we allow for usage of `TvixStoreFs` with `tvix-castore` without needing a `PathInfoService`. This introduces a new `RootNodes` trait which provides a way for the filesystem to look up CA nodes via their basename in the root directory of the filesystem. We then implement `RootNodes` for any `PathInfoService`. Additionally, the filesystem root inode tracker now stores basenames rather than `StorePath`s since `StorePath`s are specific to Nix. As a followup we can rename `TvixStoreFs` to `TvixCaStoreFs` and move it to the `castore` crate (or its own crate). b/341 Change-Id: I928372955017c23b1bf2b37190cbc508a4ed10d5 Reviewed-on: https://cl.tvl.fyi/c/depot/+/10363 Tested-by: BuildkiteCI Reviewed-by: flokli <flokli@flokli.de> |
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| docs | ||
| protos | ||
| src | ||
| build.rs | ||
| Cargo.toml | ||
| default.nix | ||
| 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.