feat: Enable gRPC reflection

Cargo.lock

@@ -1520,6 +1520,7 @@ dependencies = [
  "tokio-util",
  "tonic",
  "tonic-health",
+ "tonic-reflection",
  "tracker",
  "write_buffer",
 ]
@@ -4038,6 +4039,21 @@ dependencies = [
  "tonic-build",
 ]
 
+[[package]]
+name = "tonic-reflection"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "56498d20188550337ea6c48ecf59d11646382dbfcd61051fb98c1093cfae3c21"
+dependencies = [
+ "bytes",
+ "prost",
+ "prost-types",
+ "tokio",
+ "tokio-stream",
+ "tonic",
+ "tonic-build",
+]
+
 [[package]]
 name = "tower"
 version = "0.4.7"

Cargo.toml

@@ -97,6 +97,7 @@ tokio-stream = { version = "0.1.2", features = ["net"] }
 tokio-util = { version = "0.6.3" }
 tonic = "0.4.0"
 tonic-health = "0.3.0"
+tonic-reflection = "0.1.0"
 
 [dev-dependencies]
 # Workspace dependencies, in alphabetical order

generated_types/build.rs

@@ -1,5 +1,6 @@
 //! Compiles Protocol Buffers into native Rust types.
 
+use std::env;
 use std::path::{Path, PathBuf};
 
 type Error = Box<dyn std::error::Error>;
@@ -69,7 +70,11 @@ fn generate_grpc_types(root: &Path) -> Result<()> {
         )
         .extern_path(".google.protobuf", "::google_types::protobuf");
 
-    tonic_build::configure().compile_with_config(config, &proto_files, &[root.into()])?;
+    let descriptor_path = PathBuf::from(env::var("OUT_DIR").unwrap()).join("proto_descriptor.bin");
+    tonic_build::configure()
+        .file_descriptor_set_path(&descriptor_path)
+        .format(true)
+        .compile_with_config(config, &proto_files, &[root.into()])?;
 
     Ok(())
 }

generated_types/src/lib.rs

@@ -102,6 +102,11 @@ pub fn protobuf_type_url(protobuf_type: &str) -> String {
     format!("{}/{}", ANY_TYPE_PREFIX, protobuf_type)
 }
 
+/// Protobuf file descriptor containing all generated types.
+/// Useful in gRPC reflection.
+pub const FILE_DESCRIPTOR_SET: &'static [u8] =
+    tonic::include_file_descriptor_set!("proto_descriptor");
+
 /// Compares the protobuf type URL found within a google.protobuf.Any
 /// message to an expected Protobuf package and message name
 ///

src/influxdb_ioxd.rs

@@ -50,7 +50,7 @@ pub enum Error {
     ServingHttp { source: hyper::Error },
 
     #[snafu(display("Error serving RPC: {}", source))]
-    ServingRpc { source: tonic::transport::Error },
+    ServingRpc { source: rpc::Error },
 
     #[snafu(display(
         "Specified {} for the object store, required configuration missing for {}",

src/influxdb_ioxd/rpc.rs

@@ -5,6 +5,7 @@ use tokio::net::TcpListener;
 use tokio_stream::wrappers::TcpListenerStream;
 
 use server::{ConnectionManager, Server};
+use snafu::{ResultExt, Snafu};
 use tokio_util::sync::CancellationToken;
 
 pub mod error;
@@ -15,6 +16,19 @@ mod storage;
 mod testing;
 mod write;
 
+#[derive(Debug, Snafu)]
+pub enum Error {
+    #[snafu(display("gRPC transport error: {}", source))]
+    TransportError { source: tonic::transport::Error },
+
+    #[snafu(display("gRPC reflection error: {}", source))]
+    ReflectionError {
+        source: tonic_reflection::server::Error,
+    },
+}
+
+pub type Result<T, E = Error> = std::result::Result<T, E>;
+
 /// Instantiate a server listening on the specified address
 /// implementing the IOx, Storage, and Flight gRPC interfaces, the
 /// underlying hyper server instance. Resolves when the server has
@@ -23,13 +37,17 @@ pub async fn serve<M>(
     socket: TcpListener,
     server: Arc<Server<M>>,
     shutdown: CancellationToken,
-) -> Result<(), tonic::transport::Error>
+) -> Result<()>
 where
     M: ConnectionManager + Send + Sync + Debug + 'static,
 {
     let stream = TcpListenerStream::new(socket);
 
     let (mut health_reporter, health_service) = tonic_health::server::health_reporter();
+    let reflection_service = tonic_reflection::server::Builder::configure()
+        .register_encoded_file_descriptor_set(generated_types::FILE_DESCRIPTOR_SET)
+        .build()
+        .context(ReflectionError)?;
 
     let services = [
         generated_types::STORAGE_SERVICE,
@@ -45,6 +63,7 @@ where
 
     tonic::transport::Server::builder()
         .add_service(health_service)
+        .add_service(reflection_service)
         .add_service(testing::make_server())
         .add_service(storage::make_server(
             Arc::clone(&server),
@@ -56,4 +75,5 @@ where
         .add_service(operations::make_server(server))
         .serve_with_incoming_shutdown(stream, shutdown.cancelled())
         .await
+        .context(TransportError)
 }