Expose GRANDPA round state through RPC (#5375)

* grandpa: wire up basic RPC call

* grandpa: make it compile against GRANDPA with expose round state

* grandpa: use shared voter state to expose RPC endpoint

* grandpa: restructure into nested structs

* grandpa: return background rounds too

* grandpa: return error when endpoint not ready

* grandpa: collect grandpa rpc deps

* grandpa: decide to use concrete AuthorityId in finality-grandpa-rpc

* grandpa: remove unncessary type annotation

* grandpa: move error code to const

* grandpa: remove unnecessary WIP comment

* grandpa: remove Id type parameter for SharedVoterState

* grandpa: update tests to add shared_voter_state in parameters

* grandpa: remove old deprecated test

* grandpa: fix getting the correct set_id

* grandpa: make SharedVoterState a struct

* grandpa: wrap shared_voter_state in rpc_setup

* grandpa: replace spaces with tabs

* grandpa: limit RwLock write attempt to 1 sec

* grandpa: add missing doc comments and remove some pub

* Apply suggestions from code review

Co-Authored-By: Tomasz Drwięga <tomusdrw@users.noreply.github.com>
Co-Authored-By: Hernando Castano <HCastano@users.noreply.github.com>

* grandpa: update function name call after change in finality-grandpa

* grandpa: group pub use and only export voter::report

* grandpa: add missing docs

* grandpa: extract out structs used for json serialization

* grandpa: stick to u32 for fields intended for js

* grandpa: move Error type to its own file

* grandpa: group pub use better

* Apply code review suggestion

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* grandpa: use correct version of finality-granpda in rpc crate

* grandpa: add back basic rpc unit test

* grandpa: replace SharedVoterState::new() with empty()

* node: cleanup grandpa::SharedVoterState usage in macro

* grandpa: remove VoterState error variant

* grandpa: enable missing futures compat feature

* grandpa: fix typo in error variant

* grandpa: remove test_utils

* grandpa: allow mocking rpc handler components

* grandpa: rename serialized to report in rpc module

* grandpa: add proper test for RPC

* grandpa: update to finality-grandpa v0.12.1

Co-authored-by: André Silva <andre.beat@gmail.com>
Co-authored-by: Demi Obenour <demi@parity.io>
Co-authored-by: Tomasz Drwięga <tomusdrw@users.noreply.github.com>
Co-authored-by: Hernando Castano <HCastano@users.noreply.github.com>
Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

Author: 6 people

Cargo.lock

@@ -19,6 +19,7 @@ name = "node-template"
 futures = "0.3.4"
 log = "0.4.8"
 structopt = "0.3.8"
+parking_lot = "0.10.0"
 
 sc-cli = { version = "0.8.0-dev", path = "../../../client/cli" }
 sp-core = { version = "2.0.0-dev", path = "../../../primitives/core" }

bin/node-template/node/Cargo.toml

@@ -10,7 +10,9 @@ use sp_inherents::InherentDataProviders;
 use sc_executor::native_executor_instance;
 pub use sc_executor::NativeExecutor;
 use sp_consensus_aura::sr25519::{AuthorityPair as AuraPair};
-use sc_finality_grandpa::{self, FinalityProofProvider as GrandpaFinalityProofProvider, StorageAndProofProvider};
+use sc_finality_grandpa::{
+	FinalityProofProvider as GrandpaFinalityProofProvider, StorageAndProofProvider, SharedVoterState,
+};
 
 // Our native executor instance.
 native_executor_instance!(
@@ -157,7 +159,8 @@ pub fn new_full(config: Configuration) -> Result<impl AbstractService, ServiceEr
 			inherent_data_providers: inherent_data_providers.clone(),
 			telemetry_on_connect: Some(service.telemetry_on_connect_stream()),
 			voting_rule: sc_finality_grandpa::VotingRulesBuilder::default().build(),
-			prometheus_registry: service.prometheus_registry()
+			prometheus_registry: service.prometheus_registry(),
+			shared_voter_state: SharedVoterState::empty(),
 		};
 
 		// the GRANDPA voter task is considered infallible, i.e.

bin/node-template/node/src/service.rs

@@ -43,6 +43,7 @@ log = "0.4.8"
 rand = "0.7.2"
 structopt = { version = "0.3.8", optional = true }
 tracing = "0.1.10"
+parking_lot = "0.10.0"
 
 # primitives
 sp-authority-discovery = { version = "2.0.0-dev",  path = "../../../primitives/authority-discovery" }

bin/node/cli/Cargo.toml

@@ -21,7 +21,9 @@
 use std::sync::Arc;
 
 use sc_consensus_babe;
-use grandpa::{self, FinalityProofProvider as GrandpaFinalityProofProvider, StorageAndProofProvider};
+use grandpa::{
+	self, FinalityProofProvider as GrandpaFinalityProofProvider, StorageAndProofProvider,
+};
 use node_executor;
 use node_primitives::Block;
 use node_runtime::RuntimeApi;
@@ -38,8 +40,10 @@ use sc_consensus::LongestChain;
 macro_rules! new_full_start {
 	($config:expr) => {{
 		use std::sync::Arc;
+
 		type RpcExtension = jsonrpc_core::IoHandler<sc_rpc::Metadata>;
 		let mut import_setup = None;
+		let mut rpc_setup = None;
 		let inherent_data_providers = sp_inherents::InherentDataProviders::new();
 
 		let builder = sc_service::ServiceBuilder::new_full::<
@@ -88,6 +92,10 @@ macro_rules! new_full_start {
 			.with_rpc_extensions(|builder| -> std::result::Result<RpcExtension, _> {
 				let babe_link = import_setup.as_ref().map(|s| &s.2)
 					.expect("BabeLink is present for full services or set up failed; qed.");
+				let grandpa_link = import_setup.as_ref().map(|s| &s.1)
+					.expect("GRANDPA LinkHalf is present for full services or set up failed; qed.");
+				let shared_authority_set = grandpa_link.shared_authority_set();
+				let shared_voter_state = grandpa::SharedVoterState::empty();
 				let deps = node_rpc::FullDeps {
 					client: builder.client().clone(),
 					pool: builder.pool(),
@@ -97,12 +105,17 @@ macro_rules! new_full_start {
 						keystore: builder.keystore(),
 						babe_config: sc_consensus_babe::BabeLink::config(babe_link).clone(),
 						shared_epoch_changes: sc_consensus_babe::BabeLink::epoch_changes(babe_link).clone()
-					}
+					},
+					grandpa: node_rpc::GrandpaDeps {
+						shared_voter_state: shared_voter_state.clone(),
+						shared_authority_set: shared_authority_set.clone(),
+					},
 				};
+				rpc_setup = Some((shared_voter_state));
 				Ok(node_rpc::create_full(deps))
 			})?;
 
-		(builder, import_setup, inherent_data_providers)
+		(builder, import_setup, inherent_data_providers, rpc_setup)
 	}}
 }
 
@@ -128,7 +141,8 @@ macro_rules! new_full {
 			$config.disable_grandpa,
 		);
 
-		let (builder, mut import_setup, inherent_data_providers) = new_full_start!($config);
+		let (builder, mut import_setup, inherent_data_providers, mut rpc_setup) =
+			new_full_start!($config);
 
 		let service = builder
 			.with_finality_proof_provider(|client, backend| {
@@ -139,7 +153,10 @@ macro_rules! new_full {
 			.build()?;
 
 		let (block_import, grandpa_link, babe_link) = import_setup.take()
-				.expect("Link Half and Block Import are present for Full Services or setup failed before. qed");
+			.expect("Link Half and Block Import are present for Full Services or setup failed before. qed");
+
+		let shared_voter_state = rpc_setup.take()
+			.expect("The SharedVoterState is present for Full Services or setup failed before. qed");
 
 		($with_startup_data)(&block_import, &babe_link);
 
@@ -240,6 +257,7 @@ macro_rules! new_full {
 				telemetry_on_connect: Some(service.telemetry_on_connect_stream()),
 				voting_rule: grandpa::VotingRulesBuilder::default().build(),
 				prometheus_registry: service.prometheus_registry(),
+				shared_voter_state,
 			};
 
 			// the GRANDPA voter task is considered infallible, i.e.

bin/node/cli/src/service.rs

@@ -28,3 +28,5 @@ sc-keystore = { version = "2.0.0-dev", path = "../../../client/keystore" }
 sc-consensus-epochs = { version = "0.8.0-dev", path = "../../../client/consensus/epochs" }
 sp-consensus = { version = "0.8.0-dev", path = "../../../primitives/consensus/common" }
 sp-blockchain = { version = "2.0.0-dev", path = "../../../primitives/blockchain" }
+sc-finality-grandpa = { version = "0.8.0-dev", path = "../../../client/finality-grandpa" }
+sc-finality-grandpa-rpc = { version = "0.8.0-dev", path = "../../../client/finality-grandpa/rpc" }

bin/node/rpc/Cargo.toml

@@ -31,7 +31,7 @@
 
 use std::{sync::Arc, fmt};
 
-use node_primitives::{Block, BlockNumber, AccountId, Index, Balance};
+use node_primitives::{Block, BlockNumber, AccountId, Index, Balance, Hash};
 use node_runtime::UncheckedExtrinsic;
 use sp_api::ProvideRuntimeApi;
 use sp_transaction_pool::TransactionPool;
@@ -42,6 +42,8 @@ use sp_consensus_babe::BabeApi;
 use sc_consensus_epochs::SharedEpochChanges;
 use sc_consensus_babe::{Config, Epoch};
 use sc_consensus_babe_rpc::BabeRPCHandler;
+use sc_finality_grandpa::{SharedVoterState, SharedAuthoritySet};
+use sc_finality_grandpa_rpc::GrandpaRpcHandler;
 
 /// Light client extra dependencies.
 pub struct LightDeps<C, F, P> {
@@ -65,6 +67,14 @@ pub struct BabeDeps {
 	pub keystore: KeyStorePtr,
 }
 
+/// Extra dependencies for GRANDPA
+pub struct GrandpaDeps {
+	/// Voting round info.
+	pub shared_voter_state: SharedVoterState,
+	/// Authority set info.
+	pub shared_authority_set: SharedAuthoritySet<Hash, BlockNumber>,
+}
+
 /// Full client dependencies.
 pub struct FullDeps<C, P, SC> {
 	/// The client instance to use.
@@ -75,6 +85,8 @@ pub struct FullDeps<C, P, SC> {
 	pub select_chain: SC,
 	/// BABE specific dependencies.
 	pub babe: BabeDeps,
+	/// GRANDPA specific dependencies.
+	pub grandpa: GrandpaDeps,
 }
 
 /// Instantiate all Full RPC extensions.
@@ -102,13 +114,18 @@ pub fn create_full<C, P, M, SC>(
 		client,
 		pool,
 		select_chain,
-		babe
+		babe,
+		grandpa,
 	} = deps;
 	let BabeDeps {
 		keystore,
 		babe_config,
 		shared_epoch_changes,
 	} = babe;
+	let GrandpaDeps {
+		shared_voter_state,
+		shared_authority_set,
+	} = grandpa;
 
 	io.extend_with(
 		SystemApi::to_delegate(FullSystem::new(client.clone(), pool))
@@ -127,6 +144,11 @@ pub fn create_full<C, P, M, SC>(
 			BabeRPCHandler::new(client, shared_epoch_changes, keystore, babe_config, select_chain)
 		)
 	);
+	io.extend_with(
+		sc_finality_grandpa_rpc::GrandpaApi::to_delegate(
+			GrandpaRpcHandler::new(shared_authority_set, shared_voter_state)
+		)
+	);
 
 	io
 }

bin/node/rpc/src/lib.rs

@@ -42,11 +42,11 @@ sp-finality-tracker = { version = "2.0.0-dev", path = "../../primitives/finality
 sp-finality-grandpa = { version = "2.0.0-dev", path = "../../primitives/finality-grandpa" }
 prometheus-endpoint = { package = "substrate-prometheus-endpoint", path = "../../utils/prometheus", version = "0.8.0-dev"}
 sc-block-builder = { version = "0.8.0-dev", path = "../block-builder" }
-finality-grandpa = { version = "0.12.0", features = ["derive-codec"] }
+finality-grandpa = { version = "0.12.1", features = ["derive-codec"] }
 pin-project = "0.4.6"
 
 [dev-dependencies]
-finality-grandpa = { version = "0.12.0", features = ["derive-codec", "test-helpers"] }
+finality-grandpa = { version = "0.12.1", features = ["derive-codec", "test-helpers"] }
 sc-network = { version = "0.8.0-dev", path = "../network" }
 sc-network-test = { version = "0.8.0-dev", path = "../network/test" }
 sp-keyring = { version = "2.0.0-dev", path = "../../primitives/keyring" }

client/finality-grandpa/Cargo.toml

@@ -0,0 +1,22 @@
+[package]
+name = "sc-finality-grandpa-rpc"
+version = "0.8.0-dev"
+authors = ["Parity Technologies <admin@parity.io>"]
+description = "RPC extensions for the GRANDPA finality gadget"
+edition = "2018"
+license = "GPL-3.0"
+
+[dependencies]
+sc-finality-grandpa = { version = "0.8.0-dev", path = "../" }
+finality-grandpa = { version = "0.12.1", features = ["derive-codec"] }
+jsonrpc-core = "14.0.3"
+jsonrpc-core-client = "14.0.3"
+jsonrpc-derive = "14.0.3"
+futures = { version = "0.3.4", features = ["compat"] }
+serde = { version = "1.0.105", features = ["derive"] }
+serde_json = "1.0.50"
+log = "0.4.8"
+derive_more = "0.99.2"
+
+[dev-dependencies]
+sp-core = { version = "2.0.0-dev", path = "../../../primitives/core" }

client/finality-grandpa/rpc/Cargo.toml

@@ -0,0 +1,47 @@
+// Copyright 2020 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Substrate is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+use crate::NOT_READY_ERROR_CODE;
+
+#[derive(derive_more::Display, derive_more::From)]
+/// Top-level error type for the RPC handler
+pub enum Error {
+	/// The GRANDPA RPC endpoint is not ready.
+	#[display(fmt = "GRANDPA RPC endpoint not ready")]
+	EndpointNotReady,
+	/// GRANDPA reports the authority set id to be larger than 32-bits.
+	#[display(fmt = "GRANDPA reports authority set id unreasonably large")]
+	AuthoritySetIdReportedAsUnreasonablyLarge,
+	/// GRANDPA reports voter state with round id or weights larger than 32-bits.
+	#[display(fmt = "GRANDPA reports voter state as unreasonably large")]
+	VoterStateReportsUnreasonablyLargeNumbers,
+}
+
+impl From<Error> for jsonrpc_core::Error {
+	fn from(error: Error) -> Self {
+		jsonrpc_core::Error {
+			message: format!("{}", error).into(),
+			code: jsonrpc_core::ErrorCode::ServerError(NOT_READY_ERROR_CODE),
+			data: None,
+		}
+	}
+}
+
+impl From<std::num::TryFromIntError> for Error {
+	fn from(_error: std::num::TryFromIntError) -> Self {
+		Error::VoterStateReportsUnreasonablyLargeNumbers
+	}
+}