Initial build of server-side BeaconNodeService RPC

beacon_node/rpc/src/beacon_node.rs

@@ -0,0 +1,50 @@
+use beacon_chain::{db::ClientDB, fork_choice::ForkChoice, slot_clock::SlotClock, BeaconChain};
+use futures::Future;
+use grpcio::{RpcContext, UnarySink};
+use protos::services::{Empty, Fork, NodeInfo};
+use protos::services_grpc::BeaconNodeService;
+use slog::{debug, trace, warn};
+use std::sync::Arc;
+
+#[derive(Clone)]
+pub struct BeaconNodeServiceInstance<T, U, F>
+where
+    T: ClientDB + Clone,
+    U: SlotClock + Clone,
+    F: ForkChoice + Clone,
+{
+    pub chain: Arc<BeaconChain<T, U, F>>,
+    pub log: slog::Logger,
+}
+
+impl<T, U, F> BeaconNodeService for BeaconNodeServiceInstance<T, U, F>
+where
+    T: ClientDB + Clone,
+    U: SlotClock + Clone,
+    F: ForkChoice + Clone,
+{
+    /// Provides basic node information.
+    fn info(&mut self, ctx: RpcContext, _req: Empty, sink: UnarySink<NodeInfo>) {
+        trace!(self.log, "Node info requested via RPC");
+
+        let mut node_info = NodeInfo::new();
+        node_info.set_version(version::version());
+        // get the chain state fork
+        let state_fork = self.chain.state.read().fork.clone();
+        // build the rpc fork struct
+        let mut fork = Fork::new();
+        fork.set_previous_version(state_fork.previous_version.to_vec());
+        fork.set_current_version(state_fork.current_version.to_vec());
+        fork.set_epoch(state_fork.epoch.into());
+        node_info.set_fork(fork);
+
+        node_info.set_chain_id(self.chain.spec.chain_id as u32);
+
+        // send the node_info the requester
+        let error_log = self.log.clone();
+        let f = sink
+            .success(node_info)
+            .map_err(move |e| warn!(error_log, "failed to reply {:?}", e));
+        ctx.spawn(f)
+    }
+}