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, 8 insertions, 6 deletions

diff --git a/tvix/store/src/utils.rs b/tvix/store/src/utils.rs
index 67815fa94c4a..bd3c65a77998 100644
--- a/tvix/store/src/utils.rs
+++ b/tvix/store/src/utils.rs
@@ -51,12 +51,14 @@ pub async fn construct_services(
             .map_err(|e| io::Error::other(e.to_string()))?;
 
         if url.scheme().starts_with("grpc+") {
-            let client = PathInfoServiceClient::new(
-                tvix_castore::tonic::channel_from_url(&url)
-                    .await
-                    .map_err(|e| io::Error::other(e.to_string()))?,
-            );
-            Box::new(GRPCPathInfoService::from_client(client))
+            Box::new(GRPCPathInfoService::from_client(
+                PathInfoServiceClient::with_interceptor(
+                    tvix_castore::tonic::channel_from_url(&url)
+                        .await
+                        .map_err(|e| io::Error::other(e.to_string()))?,
+                    tvix_tracing::propagate::tonic::send_trace,
+                ),
+            ))
         } else {
             Box::new(SimpleRenderer::new(
                 blob_service.clone(),