feat(tvix/store): add logging with tracing

This uses [tracing](https://github.com/tokio-rs/tracing) for logs/
tracing.

Annotate all method handlers with an instrument macro, and warn! a
message for them being unimplemented.

Co-Authored-By: Márton Boros <martonboros@gmail.com>
Change-Id: Id42a41db33782d82abfb8dc0e49a8915000e5d89
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7665
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI

tvix/store/src/dummy_blob_service.rs

@@ -7,6 +7,9 @@ use crate::proto::PutBlobResponse;
 use crate::proto::ReadBlobRequest;
 use crate::proto::StatBlobRequest;
 use tonic::{Request, Response, Result, Status, Streaming};
+use tracing::{instrument, warn};
+
+const NOT_IMPLEMENTED_MSG: &str = "not implemented";
 
 pub struct DummyBlobService {}
 
@@ -14,21 +17,27 @@ pub struct DummyBlobService {}
 impl BlobService for DummyBlobService {
     type ReadStream = ReceiverStream<Result<BlobChunk>>;
 
+    #[instrument(skip(self))]
     async fn stat(&self, _request: Request<StatBlobRequest>) -> Result<Response<BlobMeta>> {
-        Err(Status::unimplemented("not implemented"))
+        warn!(NOT_IMPLEMENTED_MSG);
+        Err(Status::unimplemented(NOT_IMPLEMENTED_MSG))
     }
 
+    #[instrument(skip(self))]
     async fn read(
         &self,
         _request: Request<ReadBlobRequest>,
     ) -> Result<Response<Self::ReadStream>, Status> {
-        Err(Status::unimplemented("not implemented"))
+        warn!(NOT_IMPLEMENTED_MSG);
+        Err(Status::unimplemented(NOT_IMPLEMENTED_MSG))
     }
 
+    #[instrument(skip(self, _request))]
     async fn put(
         &self,
         _request: Request<Streaming<BlobChunk>>,
     ) -> Result<Response<PutBlobResponse>> {
-        Err(Status::unimplemented("not implemented"))
+        warn!(NOT_IMPLEMENTED_MSG);
+        Err(Status::unimplemented(NOT_IMPLEMENTED_MSG))
     }
 }

tvix/store/src/dummy_directory_service.rs

@@ -5,6 +5,9 @@ use crate::proto::Directory;
 use crate::proto::GetDirectoryRequest;
 use crate::proto::PutDirectoryResponse;
 use tonic::{Request, Response, Result, Status, Streaming};
+use tracing::{instrument, warn};
+
+const NOT_IMPLEMENTED_MSG: &str = "not implemented";
 
 pub struct DummyDirectoryService {}
 
@@ -12,17 +15,21 @@ pub struct DummyDirectoryService {}
 impl DirectoryService for DummyDirectoryService {
     type GetStream = ReceiverStream<Result<Directory>>;
 
+    #[instrument(skip(self))]
     async fn get(
         &self,
         _request: Request<GetDirectoryRequest>,
     ) -> Result<Response<Self::GetStream>, Status> {
-        Err(Status::unimplemented("not implemented"))
+        warn!(NOT_IMPLEMENTED_MSG);
+        Err(Status::unimplemented(NOT_IMPLEMENTED_MSG))
     }
 
+    #[instrument(skip(self, _request))]
     async fn put(
         &self,
         _request: Request<Streaming<Directory>>,
     ) -> Result<Response<PutDirectoryResponse>> {
-        Err(Status::unimplemented("not implemented"))
+        warn!(NOT_IMPLEMENTED_MSG);
+        Err(Status::unimplemented(NOT_IMPLEMENTED_MSG))
     }
 }

tvix/store/src/dummy_path_info_service.rs

@@ -4,23 +4,32 @@ use crate::proto::GetPathInfoRequest;
 use crate::proto::Node;
 use crate::proto::PathInfo;
 use tonic::{Request, Response, Result, Status};
+use tracing::{instrument, warn};
 
 pub struct DummyPathInfoService {}
 
+const NOT_IMPLEMENTED_MSG: &str = "not implemented";
+
 #[tonic::async_trait]
 impl PathInfoService for DummyPathInfoService {
+    #[instrument(skip(self))]
     async fn get(&self, _request: Request<GetPathInfoRequest>) -> Result<Response<PathInfo>> {
-        Err(Status::unimplemented("not implemented"))
+        warn!(NOT_IMPLEMENTED_MSG);
+        Err(Status::unimplemented(NOT_IMPLEMENTED_MSG))
     }
 
+    #[instrument(skip(self))]
     async fn put(&self, _request: Request<PathInfo>) -> Result<Response<PathInfo>> {
-        Err(Status::unimplemented("not implemented"))
+        warn!(NOT_IMPLEMENTED_MSG);
+        Err(Status::unimplemented(NOT_IMPLEMENTED_MSG))
     }
 
+    #[instrument(skip(self))]
     async fn calculate_nar(
         &self,
         _request: Request<Node>,
     ) -> Result<Response<CalculateNarResponse>> {
-        Err(Status::unimplemented("not implemented"))
+        warn!(NOT_IMPLEMENTED_MSG);
+        Err(Status::unimplemented(NOT_IMPLEMENTED_MSG))
     }
 }

tvix/store/src/main.rs

@@ -7,6 +7,7 @@ use crate::proto::FILE_DESCRIPTOR_SET;
 
 use clap::Parser;
 use tonic::{transport::Server, Result};
+use tracing::{info, Level};
 
 mod dummy_blob_service;
 mod dummy_directory_service;
@@ -23,6 +24,9 @@ mod tests;
 struct Cli {
     #[clap(long, short = 'l')]
     listen_address: Option<String>,
+
+    #[clap(long)]
+    log_level: Option<Level>,
 }
 
 #[tokio::main]
@@ -34,6 +38,10 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
         .parse()
         .unwrap();
 
+    let level = cli.log_level.unwrap_or(Level::INFO);
+    let subscriber = tracing_subscriber::fmt().with_max_level(level).finish();
+    tracing::subscriber::set_global_default(subscriber).ok();
+
     let mut server = Server::builder();
 
     let blob_service = dummy_blob_service::DummyBlobService {};
@@ -53,7 +61,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
         router = router.add_service(reflection_svc);
     }
 
-    println!("tvix-store listening on {}", listen_address);
+    info!("tvix-store listening on {}", listen_address);
 
     router.serve(listen_address).await?;