feat(tvix/tracing): gRPC trace context propagation r/8299

This introduces optional helper function in tvix/tracing for trace
propagation and uses these helper in the `tvix-store`.

The GRPCBlobService, GRPCDirectoryService and GRPCPathInfoService now
accept a generic client, meaning the client can be generated with either
`::new` or `::with_interceptor`.

This was tested and validated by starting a `tvix-store daemon` and
`tvix-store import`.

Change-Id: I4b194483bf09266820104b4b56e4a135dca2b77a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11863
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI

1 files changed, 13 insertions, 1 deletions

diff --git a/tvix/store/src/bin/tvix-store.rs b/tvix/store/src/bin/tvix-store.rs
index 30ebca004873..657ce06720ee 100644
--- a/tvix/store/src/bin/tvix-store.rs
+++ b/tvix/store/src/bin/tvix-store.rs
@@ -13,6 +13,8 @@ use tokio_listener::Listener;
 use tokio_listener::SystemOptions;
 use tokio_listener::UserOptions;
 use tonic::transport::Server;
+use tower::ServiceBuilder;
+use tower_http::trace::{DefaultMakeSpan, TraceLayer};
 use tracing::{info, info_span, instrument, Level, Span};
 use tracing_indicatif::span_ext::IndicatifSpanExt as _;
 use tvix_castore::import::fs::ingest_path;
@@ -215,7 +217,17 @@ async fn run_cli(cli: Cli) -> Result<(), Box<dyn std::error::Error>> {
                 .parse()
                 .unwrap();
 
-            let mut server = Server::builder();
+            let mut server = Server::builder().layer(
+                ServiceBuilder::new()
+                    .layer(
+                        TraceLayer::new_for_grpc().make_span_with(
+                            DefaultMakeSpan::new()
+                                .level(Level::INFO)
+                                .include_headers(true),
+                        ),
+                    )
+                    .map_request(tvix_tracing::propagate::tonic::accept_trace),
+            );
 
             #[allow(unused_mut)]
             let mut router = server