rpc: Enable ChainSpec for polkadot-parachain

polkadot/rpc/src/lib.rs

@@ -124,7 +124,6 @@ where
  use sc_consensus_babe_rpc::{Babe, BabeApiServer};
  use sc_consensus_beefy_rpc::{Beefy, BeefyApiServer};
  use sc_consensus_grandpa_rpc::{Grandpa, GrandpaApiServer};
- use sc_rpc_spec_v2::chain_spec::{ChainSpec, ChainSpecApiServer};
  use sc_sync_state_rpc::{SyncState, SyncStateApiServer};
  use substrate_frame_rpc_system::{System, SystemApiServer};
  use substrate_state_trie_migration_rpc::{StateMigration, StateMigrationApiServer};
@@ -139,11 +138,6 @@ where
  finality_provider,
  } = grandpa;
 
- let chain_name = chain_spec.name().to_string();
- let genesis_hash = client.hash(0).ok().flatten().expect("Genesis block exists; qed");
- let properties = chain_spec.properties();
-
- io.merge(ChainSpec::new(chain_name, genesis_hash, properties).into_rpc())?;
  io.merge(StateMigration::new(client.clone(), backend.clone(), deny_unsafe).into_rpc())?;
  io.merge(System::new(client.clone(), pool.clone(), deny_unsafe).into_rpc())?;
  io.merge(TransactionPayment::new(client.clone()).into_rpc())?;

prdoc/pr_5205.prdoc

@@ -0,0 +1,16 @@
+title: Enable ChainSpec API for polkadot-parachain
+
+doc:
+ - audience:
+ - Runtime Dev
+ - Node Dev
+ description: |
+ Enables the `chainSpec_v1` rpc-v2 API for polkadot-parachains.
+ This RPC is needed to provide extra information about the specification of the chain.
+ At the same time, this paves the way for implementing in the future a `chainSpec_v1_getSpec`
+ method that can extract the chainSpec of any chain (including parachains) for the use with lightclients.
+ For more info about the `chainSpec`, please see the specification: https://github.com/paritytech/json-rpc-interface-spec/blob/main/src/api/chainSpec.md.
+
+crates: 
+ - name: sc-service
+ bump: minor

substrate/bin/node/rpc/Cargo.toml

@@ -32,7 +32,6 @@ sc-consensus-grandpa-rpc = { workspace = true, default-features = true }
 sc-mixnet = { workspace = true, default-features = true }
 sc-rpc = { workspace = true, default-features = true }
 sc-rpc-api = { workspace = true, default-features = true }
-sc-rpc-spec-v2 = { workspace = true, default-features = true }
 sc-sync-state-rpc = { workspace = true, default-features = true }
 sc-transaction-pool-api = { workspace = true, default-features = true }
 sp-api = { workspace = true, default-features = true }

substrate/bin/node/rpc/src/lib.rs

@@ -160,7 +160,6 @@ where
  mixnet::MixnetApiServer,
  statement::StatementApiServer,
  };
- use sc_rpc_spec_v2::chain_spec::{ChainSpec, ChainSpecApiServer};
  use sc_sync_state_rpc::{SyncState, SyncStateApiServer};
  use substrate_frame_rpc_system::{System, SystemApiServer};
  use substrate_state_trie_migration_rpc::{StateMigration, StateMigrationApiServer};
@@ -176,11 +175,6 @@ where
  finality_provider,
  } = grandpa;
 
- let chain_name = chain_spec.name().to_string();
- let genesis_hash = client.block_hash(0).ok().flatten().expect("Genesis block exists; qed");
- let properties = chain_spec.properties();
- io.merge(ChainSpec::new(chain_name, genesis_hash, properties).into_rpc())?;
-
  io.merge(System::new(client.clone(), pool, deny_unsafe).into_rpc())?;
  // Making synchronous calls in light client freezes the browser currently,
  // more context: https://github.com/paritytech/substrate/pull/3480

substrate/client/service/src/builder.rs

@@ -68,6 +68,7 @@ use sc_rpc::{
 use sc_rpc_spec_v2::{
  archive::ArchiveApiServer,
  chain_head::ChainHeadApiServer,
+ chain_spec::ChainSpecApiServer,
  transaction::{TransactionApiServer, TransactionBroadcastApiServer},
 };
 use sc_telemetry::{telemetry, ConnectionMessage, Telemetry, TelemetryHandle, SUBSTRATE_INFO};
@@ -675,9 +676,8 @@ where
  // - block pruning in archive mode: The block's body is kept around
  let is_archive_node = config.state_pruning.as_ref().map(|sp| sp.is_archive()).unwrap_or(false) &&
  config.blocks_pruning.is_archive();
+ let genesis_hash = client.hash(Zero::zero()).ok().flatten().expect("Genesis block exists; qed");
  if is_archive_node {
- let genesis_hash =
- client.hash(Zero::zero()).ok().flatten().expect("Genesis block exists; qed");
  let archive_v2 = sc_rpc_spec_v2::archive::Archive::new(
  client.clone(),
  backend.clone(),
@@ -689,6 +689,14 @@ where
  rpc_api.merge(archive_v2).map_err(|e| Error::Application(e.into()))?;
  }
 
+ // ChainSpec RPC-v2.
+ let chain_spec_v2 = sc_rpc_spec_v2::chain_spec::ChainSpec::new(
+ config.chain_spec.name().into(),
+ genesis_hash,
+ config.chain_spec.properties(),
+ )
+ .into_rpc();
+
  let author = sc_rpc::author::Author::new(
  client.clone(),
  transaction_pool,
@@ -712,6 +720,7 @@ where
  .merge(transaction_broadcast_rpc_v2)
  .map_err(|e| Error::Application(e.into()))?;
  rpc_api.merge(chain_head_v2).map_err(|e| Error::Application(e.into()))?;
+ rpc_api.merge(chain_spec_v2).map_err(|e| Error::Application(e.into()))?;
 
  // Part of the old RPC spec.
  rpc_api.merge(chain).map_err(|e| Error::Application(e.into()))?;