add(scan): Start scanner gRPC server with zebrad (#8241)

* adds clear_results RPC method for zebra-scan

* adds delete_keys rpc method

* adds docs

* Update zebra-grpc/proto/scanner.proto

Co-authored-by: Alfredo Garcia <oxarbitrage@gmail.com>

* Apply suggestions from code review

* start zebra-scan gRPC server from zebrad start command

* adds a test that the scanner starts with zebrad

* adds a `listen_addr` field to the shielded scan config

* updates test to use a random port and set the listen_addr config field

* fixes test

* Update zebra-scan/src/config.rs

Co-authored-by: Alfredo Garcia <oxarbitrage@gmail.com>

* fixes panic when trying to open multiple mutable storage instances.

* open db in blocking task

* fixes test

---------

Co-authored-by: Alfredo Garcia <oxarbitrage@gmail.com>

Cargo.lock

@@ -6065,6 +6065,7 @@ dependencies = [
  "vergen",
  "zebra-chain",
  "zebra-consensus",
+ "zebra-grpc",
  "zebra-network",
  "zebra-node-services",
  "zebra-rpc",

zebra-grpc/src/lib.rs

@@ -5,3 +5,8 @@
 #![doc(html_root_url = "https://docs.rs/zebra_grpc")]
 
 pub mod server;
+
+/// The generated scanner proto
+pub mod scanner {
+    tonic::include_proto!("scanner");
+}

zebra-grpc/src/server.rs

@@ -1,20 +1,19 @@
 //! The gRPC server implementation
 
+use std::net::SocketAddr;
+
 use futures_util::future::TryFutureExt;
 use tonic::{transport::Server, Response, Status};
 use tower::ServiceExt;
 
-use scanner::scanner_server::{Scanner, ScannerServer};
-use scanner::{ClearResultsRequest, DeleteKeysRequest, Empty, InfoReply};
-
 use zebra_node_services::scan_service::{
     request::Request as ScanServiceRequest, response::Response as ScanServiceResponse,
 };
 
-/// The generated scanner proto
-pub mod scanner {
-    tonic::include_proto!("scanner");
-}
+use crate::scanner::{
+    scanner_server::{Scanner, ScannerServer},
+    ClearResultsRequest, DeleteKeysRequest, Empty, InfoReply,
+};
 
 type BoxError = Box<dyn std::error::Error + Send + Sync + 'static>;
 
@@ -61,7 +60,7 @@ where
             ));
         };
 
-        let reply = scanner::InfoReply {
+        let reply = InfoReply {
             min_sapling_birthday_height: min_sapling_birthday_height.0,
         };
 
@@ -124,7 +123,10 @@ where
 }
 
 /// Initializes the zebra-scan gRPC server
-pub async fn init<ScanService>(scan_service: ScanService) -> Result<(), color_eyre::Report>
+pub async fn init<ScanService>(
+    listen_addr: SocketAddr,
+    scan_service: ScanService,
+) -> Result<(), color_eyre::Report>
 where
     ScanService: tower::Service<ScanServiceRequest, Response = ScanServiceResponse, Error = BoxError>
         + Clone
@@ -133,12 +135,11 @@ where
         + 'static,
     <ScanService as tower::Service<ScanServiceRequest>>::Future: Send,
 {
-    let addr = "[::1]:50051".parse()?;
     let service = ScannerRPC { scan_service };
 
     Server::builder()
         .add_service(ScannerServer::new(service))
-        .serve(addr)
+        .serve(listen_addr)
         .await?;
 
     Ok(())

zebra-scan/src/bin/rpc_server.rs

@@ -14,7 +14,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     let scan_service = ServiceBuilder::new().buffer(10).service(scan_service);
 
     // Start the gRPC server.
-    zebra_grpc::server::init(scan_service).await?;
+    zebra_grpc::server::init("127.0.0.1:8231".parse()?, scan_service).await?;
 
     Ok(())
 }

zebra-scan/src/config.rs

@@ -1,6 +1,6 @@
 //! Configuration for blockchain scanning tasks.
 
-use std::fmt::Debug;
+use std::{fmt::Debug, net::SocketAddr};
 
 use indexmap::IndexMap;
 use serde::{Deserialize, Serialize};
@@ -20,6 +20,20 @@ pub struct Config {
     // TODO: allow keys without birthdays
     pub sapling_keys_to_scan: IndexMap<SaplingScanningKey, u32>,
 
+    /// IP address and port for the zebra-scan gRPC server.
+    ///
+    /// Note: The gRPC server is disabled by default.
+    /// To enable the gRPC server, set a listen address in the config:
+    /// ```toml
+    /// [shielded-scan]
+    /// listen_addr = '127.0.0.1:8231'
+    /// ```
+    ///
+    /// The recommended ports for the gRPC server are:
+    /// - Mainnet: 127.0.0.1:8231
+    /// - Testnet: 127.0.0.1:18231
+    pub listen_addr: Option<SocketAddr>,
+
     /// The scanner results database config.
     //
     // TODO: Remove fields that are only used by the state, and create a common database config.
@@ -41,6 +55,9 @@ impl Default for Config {
     fn default() -> Self {
         Self {
             sapling_keys_to_scan: IndexMap::new(),
+            listen_addr: None,
+
+            // TODO: Add a const generic for specifying the default cache_dir path, like 'zebra' or 'zebra-scan'?
             db_config: DbConfig::default(),
         }
     }

zebra-scan/src/init.rs

@@ -1,31 +1,66 @@
 //! Initializing the scanner and gRPC server.
 
+use std::net::SocketAddr;
+
 use color_eyre::Report;
+use tokio::task::JoinHandle;
 use tower::ServiceBuilder;
 
-use zebra_chain::parameters::Network;
+use tracing::Instrument;
+use zebra_chain::{diagnostic::task::WaitForPanics, parameters::Network};
 use zebra_state::ChainTipChange;
 
-use crate::{scan, service::ScanService, Config};
+use crate::{scan, service::ScanService, storage::Storage, Config};
 
 /// Initialize [`ScanService`] based on its config.
 ///
 /// TODO: add a test for this function.
-pub async fn init(
+pub async fn init_with_server(
+    listen_addr: SocketAddr,
     config: Config,
     network: Network,
     state: scan::State,
     chain_tip_change: ChainTipChange,
 ) -> Result<(), Report> {
-    let scan_service = ServiceBuilder::new().buffer(10).service(ScanService::new(
-        &config,
-        network,
-        state,
-        chain_tip_change,
-    ));
+    info!(?config, "starting scan service");
+    let scan_service = ServiceBuilder::new()
+        .buffer(10)
+        .service(ScanService::new(&config, network, state, chain_tip_change).await);
+
+    // TODO: move this to zebra-grpc init() function and include addr
+    info!("starting scan gRPC server");
 
     // Start the gRPC server.
-    zebra_grpc::server::init(scan_service).await?;
+    zebra_grpc::server::init(listen_addr, scan_service).await?;
 
     Ok(())
 }
+
+/// Initialize the scanner and its gRPC server based on its config, and spawn a task for it.
+pub fn spawn_init(
+    config: Config,
+    network: Network,
+    state: scan::State,
+    chain_tip_change: ChainTipChange,
+) -> JoinHandle<Result<(), Report>> {
+    if let Some(listen_addr) = config.listen_addr {
+        // TODO: spawn an entirely new executor here, to avoid timing attacks.
+        tokio::spawn(
+            init_with_server(listen_addr, config, network, state, chain_tip_change)
+                .in_current_span(),
+        )
+    } else {
+        // TODO: spawn an entirely new executor here, to avoid timing attacks.
+        tokio::spawn(
+            async move {
+                let storage =
+                    tokio::task::spawn_blocking(move || Storage::new(&config, network, false))
+                        .wait_for_panics()
+                        .await;
+                let (_cmd_sender, cmd_receiver) = std::sync::mpsc::channel();
+                scan::start(state, chain_tip_change, storage, cmd_receiver).await
+            }
+            .in_current_span(),
+        )
+    }
+}

zebra-scan/src/lib.rs

@@ -21,6 +21,6 @@ pub use service::scan_task::scan;
 pub mod tests;
 
 pub use config::Config;
-pub use init::init;
+pub use init::{init_with_server, spawn_init};
 
 pub use zcash_primitives::{sapling::SaplingIvk, zip32::DiversifiableFullViewingKey};

zebra-scan/src/service.rs

@@ -5,7 +5,7 @@ use std::{collections::BTreeMap, future::Future, pin::Pin, task::Poll, time::Dur
 use futures::future::FutureExt;
 use tower::Service;
 
-use zebra_chain::{parameters::Network, transaction::Hash};
+use zebra_chain::{diagnostic::task::WaitForPanics, parameters::Network, transaction::Hash};
 
 use zebra_state::ChainTipChange;
 
@@ -36,15 +36,20 @@ const DELETE_KEY_TIMEOUT: Duration = Duration::from_secs(15);
 
 impl ScanService {
     /// Create a new [`ScanService`].
-    pub fn new(
+    pub async fn new(
         config: &Config,
         network: Network,
         state: scan::State,
         chain_tip_change: ChainTipChange,
     ) -> Self {
+        let config = config.clone();
+        let storage = tokio::task::spawn_blocking(move || Storage::new(&config, network, false))
+            .wait_for_panics()
+            .await;
+
         Self {
-            db: Storage::new(config, network, false),
-            scan_task: ScanTask::spawn(config, network, state, chain_tip_change),
+            scan_task: ScanTask::spawn(storage.clone(), state, chain_tip_change),
+            db: storage,
         }
     }
 

zebra-scan/src/service/scan_task.rs

@@ -5,10 +5,9 @@ use std::sync::{mpsc, Arc};
 use color_eyre::Report;
 use tokio::task::JoinHandle;
 
-use zebra_chain::parameters::Network;
 use zebra_state::ChainTipChange;
 
-use crate::Config;
+use crate::storage::Storage;
 
 mod commands;
 mod executor;
@@ -31,23 +30,12 @@ pub struct ScanTask {
 
 impl ScanTask {
     /// Spawns a new [`ScanTask`].
-    pub fn spawn(
-        config: &Config,
-        network: Network,
-        state: scan::State,
-        chain_tip_change: ChainTipChange,
-    ) -> Self {
+    pub fn spawn(db: Storage, state: scan::State, chain_tip_change: ChainTipChange) -> Self {
         // TODO: Use a bounded channel or move this logic to the scan service or another service.
         let (cmd_sender, cmd_receiver) = mpsc::channel();
 
         Self {
-            handle: Arc::new(scan::spawn_init(
-                config,
-                network,
-                state,
-                chain_tip_change,
-                cmd_receiver,
-            )),
+            handle: Arc::new(scan::spawn_init(db, state, chain_tip_change, cmd_receiver)),
             cmd_sender,
         }
     }

zebra-scan/src/service/scan_task/scan.rs

@@ -39,7 +39,6 @@ use zebra_state::{ChainTipChange, SaplingScannedResult, TransactionIndex};
 use crate::{
     service::{ScanTask, ScanTaskCommand},
     storage::{SaplingScanningKey, Storage},
-    Config,
 };
 
 use super::executor;
@@ -489,32 +488,10 @@ async fn tip_height(mut state: State) -> Result<Height, Report> {
 ///
 /// TODO: add a test for this function.
 pub fn spawn_init(
-    config: &Config,
-    network: Network,
+    storage: Storage,
     state: State,
     chain_tip_change: ChainTipChange,
     cmd_receiver: Receiver<ScanTaskCommand>,
 ) -> JoinHandle<Result<(), Report>> {
-    let config = config.clone();
-
-    // TODO: spawn an entirely new executor here, to avoid timing attacks.
-    tokio::spawn(init(config, network, state, chain_tip_change, cmd_receiver).in_current_span())
-}
-
-/// Initialize the scanner based on its config.
-///
-/// TODO: add a test for this function.
-pub async fn init(
-    config: Config,
-    network: Network,
-    state: State,
-    chain_tip_change: ChainTipChange,
-    cmd_receiver: Receiver<ScanTaskCommand>,
-) -> Result<(), Report> {
-    let storage = tokio::task::spawn_blocking(move || Storage::new(&config, network, false))
-        .wait_for_panics()
-        .await;
-
-    // TODO: add more tasks here?
-    start(state, chain_tip_change, storage, cmd_receiver).await
+    tokio::spawn(start(state, chain_tip_change, storage, cmd_receiver).in_current_span())
 }

zebrad/Cargo.toml

@@ -289,6 +289,7 @@ zebra-scan = { path = "../zebra-scan", features = ["proptest-impl"] }
 zebra-node-services = { path = "../zebra-node-services", features = ["rpc-client"] }
 
 zebra-test = { path = "../zebra-test" }
+zebra-grpc = { path = "../zebra-grpc" }
 
 # Used by the checkpoint generation tests via the zebra-checkpoints feature
 # (the binaries in this crate won't be built unless their features are enabled).

zebrad/src/commands/start.rs

@@ -301,25 +301,16 @@ impl StartCmd {
 
         #[cfg(feature = "shielded-scan")]
         // Spawn never ending scan task only if we have keys to scan for.
-        let (scan_task_handle, _cmd_sender) =
-            if !config.shielded_scan.sapling_keys_to_scan.is_empty() {
-                // TODO: log the number of keys and update the scan_task_starts() test
-                info!("spawning shielded scanner with configured viewing keys");
-                let scan_task = zebra_scan::service::scan_task::ScanTask::spawn(
-                    &config.shielded_scan,
-                    config.network.network,
-                    state,
-                    chain_tip_change,
-                );
-
-                (
-                    std::sync::Arc::into_inner(scan_task.handle)
-                        .expect("should only have one reference here"),
-                    Some(scan_task.cmd_sender),
-                )
-            } else {
-                (tokio::spawn(std::future::pending().in_current_span()), None)
-            };
+        let scan_task_handle = {
+            // TODO: log the number of keys and update the scan_task_starts() test
+            info!("spawning shielded scanner with configured viewing keys");
+            zebra_scan::spawn_init(
+                config.shielded_scan.clone(),
+                config.network.network,
+                state,
+                chain_tip_change,
+            )
+        };
 
         #[cfg(not(feature = "shielded-scan"))]
         // Spawn a dummy scan task which doesn't do anything and never finishes.