ChainSpec trait (#5185)

* ChainSpec trait

* Apply suggestions from code review

Co-Authored-By: Bastian Köcher <bkchr@users.noreply.github.com>

* Added docs

* Fixed build

* Fixed build

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

substrate/bin/node-template/node/src/chain_spec.rs

@@ -12,7 +12,7 @@ use sp_runtime::traits::{Verify, IdentifyAccount};
 //const STAGING_TELEMETRY_URL: &str = "wss://telemetry.polkadot.io/submit/";
 
 /// Specialized `ChainSpec`. This is a specialization of the general Substrate ChainSpec type.
-pub type ChainSpec = sc_service::ChainSpec<GenesisConfig>;
+pub type ChainSpec = sc_service::GenericChainSpec<GenesisConfig>;
 
 /// The chain specification option. This is expected to come in from the CLI and
 /// is little more than one of a number of alternatives which can easily be converted
@@ -142,9 +142,9 @@ fn testnet_genesis(initial_authorities: Vec<(AuraId, GrandpaId)>,
 	}
 }
 
-pub fn load_spec(id: &str) -> Result<Option<ChainSpec>, String> {
+pub fn load_spec(id: &str) -> Result<Box<dyn sc_service::ChainSpec>, String> {
 	Ok(match Alternative::from(id) {
-		Some(spec) => Some(spec.load()?),
-		None => None,
+		Some(spec) => Box::new(spec.load()?),
+		None => Box::new(ChainSpec::from_json_file(std::path::PathBuf::from(id))?),
 	})
 }

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

@@ -4,7 +4,7 @@ use std::sync::Arc;
 use std::time::Duration;
 use sc_client::LongestChain;
 use sc_client_api::ExecutorProvider;
-use node_template_runtime::{self, GenesisConfig, opaque::Block, RuntimeApi};
+use node_template_runtime::{self, opaque::Block, RuntimeApi};
 use sc_service::{error::{Error as ServiceError}, AbstractService, Configuration, ServiceBuilder};
 use sp_inherents::InherentDataProviders;
 use sc_executor::native_executor_instance;
@@ -69,7 +69,7 @@ macro_rules! new_full_start {
 }
 
 /// Builds a new service for a full client.
-pub fn new_full(config: Configuration<GenesisConfig>)
+pub fn new_full(config: Configuration)
 	-> Result<impl AbstractService, ServiceError>
 {
 	let is_authority = config.roles.is_authority();
@@ -181,7 +181,7 @@ pub fn new_full(config: Configuration<GenesisConfig>)
 }
 
 /// Builds a new service for a light client.
-pub fn new_light(config: Configuration<GenesisConfig>)
+pub fn new_light(config: Configuration)
 	-> Result<impl AbstractService, ServiceError>
 {
 	let inherent_data_providers = InherentDataProviders::new();

substrate/bin/node/cli/src/chain_spec.rs

@@ -56,7 +56,7 @@ pub struct Extensions {
 }
 
 /// Specialized `ChainSpec`.
-pub type ChainSpec = sc_service::ChainSpec<
+pub type ChainSpec = sc_service::GenericChainSpec<
 	GenesisConfig,
 	Extensions,
 >;

substrate/bin/node/cli/src/command.rs

@@ -46,7 +46,7 @@ where
 			cmd.update_config(&mut config, load_spec, &version)?;
 
 			let client = sc_service::new_full_client::<
-				node_runtime::Block, node_runtime::RuntimeApi, node_executor::Executor, _, _,
+				node_runtime::Block, node_runtime::RuntimeApi, node_executor::Executor,
 			>(&config)?;
 			let inspect = node_inspect::Inspector::<node_runtime::Block>::new(client);
 
@@ -56,7 +56,7 @@ where
 			cmd.init(&version)?;
 			cmd.update_config(&mut config, load_spec, &version)?;
 
-			cmd.run::<_, _, node_runtime::Block, node_executor::Executor>(config)
+			cmd.run::<node_runtime::Block, node_executor::Executor>(config)
 		},
 		Some(Subcommand::Factory(cli_args)) => {
 			cli_args.shared_params.init(&version)?;
@@ -108,7 +108,7 @@ where
 			subcommand.update_config(&mut config, load_spec, &version)?;
 			subcommand.run(
 				config,
-				|config: service::NodeConfiguration| Ok(new_full_start!(config).0),
+				|config: sc_service::Configuration| Ok(new_full_start!(config).0),
 			)
 		},
 	}

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

@@ -83,9 +83,9 @@ impl ChainSpec {
 	}
 }
 
-fn load_spec(id: &str) -> Result<Option<chain_spec::ChainSpec>, String> {
+fn load_spec(id: &str) -> Result<Box<dyn sc_service::ChainSpec>, String> {
 	Ok(match ChainSpec::from(id) {
-		Some(spec) => Some(spec.load()?),
-		None => None,
+		Some(spec) => Box::new(spec.load()?),
+		None => Box::new(chain_spec::ChainSpec::from_json_file(std::path::PathBuf::from(id))?),
 	})
 }

substrate/bin/node/cli/src/service.rs

@@ -25,7 +25,7 @@ use sc_client::{self, LongestChain};
 use grandpa::{self, FinalityProofProvider as GrandpaFinalityProofProvider, StorageAndProofProvider};
 use node_executor;
 use node_primitives::Block;
-use node_runtime::{GenesisConfig, RuntimeApi};
+use node_runtime::RuntimeApi;
 use sc_service::{
 	AbstractService, ServiceBuilder, config::Configuration, error::{Error as ServiceError},
 };
@@ -270,11 +270,8 @@ type ConcreteTransactionPool = sc_transaction_pool::BasicPool<
 	ConcreteBlock
 >;
 
-/// A specialized configuration object for setting up the node..
-pub type NodeConfiguration = Configuration<GenesisConfig, crate::chain_spec::Extensions>;
-
 /// Builds a new service for a full client.
-pub fn new_full(config: NodeConfiguration)
+pub fn new_full(config: Configuration)
 -> Result<
 	Service<
 		ConcreteBlock,
@@ -296,7 +293,7 @@ pub fn new_full(config: NodeConfiguration)
 }
 
 /// Builds a new service for a light client.
-pub fn new_light(config: NodeConfiguration)
+pub fn new_light(config: Configuration)
 -> Result<impl AbstractService, ServiceError> {
 	type RpcExtension = jsonrpc_core::IoHandler<sc_rpc::Metadata>;
 	let inherent_data_providers = InherentDataProviders::new();

substrate/bin/node/inspect/src/command.rs

@@ -31,15 +31,12 @@ impl InspectCmd {
 	}
 
 	/// Parse CLI arguments and initialize given config.
-	pub fn update_config<G, E>(
+	pub fn update_config(
 		&self,
-		mut config: &mut sc_service::config::Configuration<G, E>,
-		spec_factory: impl FnOnce(&str) -> Result<Option<sc_service::ChainSpec<G, E>>, String>,
+		mut config: &mut sc_service::config::Configuration,
+		spec_factory: impl FnOnce(&str) -> Result<Box<dyn sc_service::ChainSpec>, String>,
 		version: &sc_cli::VersionInfo,
-	) -> sc_cli::Result<()> where
-		G: sc_service::RuntimeGenesis,
-		E: sc_service::ChainSpecExtension,
-	{
+	) -> sc_cli::Result<()> {
 		self.shared_params.update_config(config, spec_factory, version)?;
 
 		// make sure to configure keystore

substrate/bin/utils/chain-spec-builder/src/main.rs

@@ -128,7 +128,7 @@ fn generate_chain_spec(
 		Default::default(),
 	);
 
-	chain_spec.to_json(false).map_err(|err| err.to_string())
+	chain_spec.as_json(false).map_err(|err| err.to_string())
 }
 
 fn generate_authority_keys_and_store(

substrate/client/chain-spec/derive/src/impls.rs

@@ -50,6 +50,15 @@ pub fn extension_derive(ast: &DeriveInput) -> proc_macro::TokenStream {
 						_ => None,
 					}
 				}
+
+				fn get_any(&self, t: std::any::TypeId) -> &dyn std::any::Any {
+					use std::any::{Any, TypeId};
+
+					match t {
+						#( x if x == TypeId::of::<#field_types>() => &self.#field_names ),*,
+						_ => self,
+					}
+				}
 			}
 		}
 	})

substrate/client/chain-spec/src/chain_spec.rs

@@ -26,6 +26,7 @@ use sp_core::storage::{StorageKey, StorageData, ChildInfo, Storage, StorageChild
 use sp_runtime::BuildStorage;
 use serde_json as json;
 use crate::RuntimeGenesis;
+use crate::extension::GetExtension;
 use sc_network::Multiaddr;
 use sc_telemetry::TelemetryEndpoints;
 
@@ -269,9 +270,9 @@ impl<G, E: serde::de::DeserializeOwned> ChainSpec<G, E> {
 	}
 }
 
-impl<G: RuntimeGenesis, E: serde::Serialize> ChainSpec<G, E> {
+impl<G: RuntimeGenesis, E: serde::Serialize + Clone> ChainSpec<G, E> {
 	/// Dump to json string.
-	pub fn to_json(self, raw: bool) -> Result<String, String> {
+	pub fn as_json(&self, raw: bool) -> Result<String, String> {
 		#[derive(Serialize, Deserialize)]
 		struct Container<G, E> {
 			#[serde(flatten)]
@@ -306,7 +307,7 @@ impl<G: RuntimeGenesis, E: serde::Serialize> ChainSpec<G, E> {
 			(_, genesis) => genesis,
 		};
 		let container = Container {
-			client_spec: self.client_spec,
+			client_spec: self.client_spec.clone(),
 			genesis,
 		};
 		json::to_string_pretty(&container)
@@ -314,6 +315,52 @@ impl<G: RuntimeGenesis, E: serde::Serialize> ChainSpec<G, E> {
 	}
 }
 
+impl<G, E> crate::ChainSpec for ChainSpec<G, E>
+where
+	G: RuntimeGenesis,
+	E: GetExtension + serde::Serialize + Clone,
+{
+	fn boot_nodes(&self) -> &[String] {
+		ChainSpec::boot_nodes(self)
+	}
+
+	fn name(&self) -> &str {
+		ChainSpec::name(self)
+	}
+
+	fn id(&self) -> &str {
+		ChainSpec::id(self)
+	}
+
+	fn telemetry_endpoints(&self) -> &Option<TelemetryEndpoints> {
+		ChainSpec::telemetry_endpoints(self)
+	}
+
+	fn protocol_id(&self) -> Option<&str> {
+		ChainSpec::protocol_id(self)
+	}
+
+	fn properties(&self) -> Properties {
+		ChainSpec::properties(self)
+	}
+
+	fn add_boot_node(&mut self, addr: Multiaddr) {
+		ChainSpec::add_boot_node(self, addr)
+	}
+
+	fn extensions(&self) -> &dyn GetExtension {
+		ChainSpec::extensions(self) as &dyn GetExtension
+	}
+
+	fn as_json(&self, raw: bool) -> Result<String, String> {
+		ChainSpec::as_json(self, raw)
+	}
+
+	fn as_storage_builder(&self) -> &dyn BuildStorage {
+		self
+	}
+}
+
 #[cfg(test)]
 mod tests {
 	use super::*;
@@ -344,7 +391,7 @@ mod tests {
 			PathBuf::from("./res/chain_spec.json")
 		).unwrap();
 
-		assert_eq!(spec1.to_json(false), spec2.to_json(false));
+		assert_eq!(spec1.as_json(false), spec2.as_json(false));
 	}
 
 	#[derive(Debug, Serialize, Deserialize)]

substrate/client/chain-spec/src/extension.rs

@@ -17,6 +17,8 @@
 //! Chain Spec extensions helpers.
 
 use std::fmt::Debug;
+use std::any::{TypeId, Any};
+
 use std::collections::BTreeMap;
 
 use serde::{Serialize, Deserialize, de::DeserializeOwned};
@@ -120,6 +122,8 @@ pub trait Extension: Serialize + DeserializeOwned + Clone {
 
 	/// Get an extension of specific type.
 	fn get<T: 'static>(&self) -> Option<&T>;
+	/// Get an extension of specific type as refernce to `Any`
+	fn get_any(&self, t: TypeId) -> &dyn Any;
 
 	/// Get forkable extensions of specific type.
 	fn forks<BlockNumber, T>(&self) -> Option<Forks<BlockNumber, T>> where
@@ -137,6 +141,7 @@ impl Extension for crate::NoExtension {
 	type Forks = Self;
 
 	fn get<T: 'static>(&self) -> Option<&T> { None }
+	fn get_any(&self, _t: TypeId) -> &dyn Any { self }
 }
 
 pub trait IsForks {
@@ -225,22 +230,25 @@ impl<B, E> Extension for Forks<B, E> where
 	type Forks = Self;
 
 	fn get<T: 'static>(&self) -> Option<&T> {
-		use std::any::{TypeId, Any};
-
 		match TypeId::of::<T>() {
 			x if x == TypeId::of::<E>() => Any::downcast_ref(&self.base),
 			_ => self.base.get(),
 		}
 	}
 
+	fn get_any(&self, t: TypeId) -> &dyn Any {
+		match t {
+			x if x == TypeId::of::<E>() => &self.base,
+			_ => self.base.get_any(t),
+		}
+	}
+
 	fn forks<BlockNumber, T>(&self) -> Option<Forks<BlockNumber, T>> where
 		BlockNumber: Ord + Clone + 'static,
 		T: Group + 'static,
 		<Self::Forks as IsForks>::Extension: Extension,
 		<<Self::Forks as IsForks>::Extension as Group>::Fork: Extension,
 	{
-		use std::any::{TypeId, Any};
-
 		if TypeId::of::<BlockNumber>() == TypeId::of::<B>() {
 			Any::downcast_ref(&self.for_type::<T>()?).cloned()
 		} else {
@@ -250,6 +258,24 @@ impl<B, E> Extension for Forks<B, E> where
 	}
 }
 
+/// A subset if the `Extension` trait that only allows for quering extensions.
+pub trait GetExtension {
+	/// Get an extension of specific type.
+	fn get_any(&self, t: TypeId) -> &dyn Any;
+}
+
+impl <E: Extension> GetExtension for E {
+	fn get_any(&self, t: TypeId) -> &dyn Any {
+		Extension::get_any(self, t)
+	}
+}
+
+/// Helper function that queries an extension by type from `GetExtension`
+/// trait object.
+pub fn get_extension<T: 'static>(e: &dyn GetExtension) -> Option<&T> {
+	Any::downcast_ref(GetExtension::get_any(e, TypeId::of::<T>()))
+}
+
 #[cfg(test)]
 mod tests {
 	use super::*;

substrate/client/chain-spec/src/lib.rs

@@ -30,14 +30,14 @@
 //! ```rust
 //! use std::collections::HashMap;
 //! use serde::{Serialize, Deserialize};
-//! use sc_chain_spec::{ChainSpec, ChainSpecExtension};
+//! use sc_chain_spec::{GenericChainSpec, ChainSpecExtension};
 //!
 //! #[derive(Clone, Debug, Serialize, Deserialize, ChainSpecExtension)]
 //! pub struct MyExtension {
 //!		pub known_blocks: HashMap<u64, String>,
 //! }
 //!
-//! pub type MyChainSpec<G> = ChainSpec<G, MyExtension>;
+//! pub type MyChainSpec<G> = GenericChainSpec<G, MyExtension>;
 //! ```
 //!
 //! Some parameters may require different values depending on the
@@ -49,7 +49,7 @@
 //!
 //! ```rust
 //! use serde::{Serialize, Deserialize};
-//! use sc_chain_spec::{Forks, ChainSpec, ChainSpecGroup, ChainSpecExtension};
+//! use sc_chain_spec::{Forks, ChainSpecGroup, ChainSpecExtension, GenericChainSpec};
 //!
 //! #[derive(Clone, Debug, Serialize, Deserialize, ChainSpecGroup)]
 //! pub struct ClientParams {
@@ -71,10 +71,10 @@
 //! pub type BlockNumber = u64;
 //!
 //! /// A chain spec supporting forkable `ClientParams`.
-//! pub type MyChainSpec1<G> = ChainSpec<G, Forks<BlockNumber, ClientParams>>;
+//! pub type MyChainSpec1<G> = GenericChainSpec<G, Forks<BlockNumber, ClientParams>>;
 //!
 //! /// A chain spec supporting forkable `Extension`.
-//! pub type MyChainSpec2<G> = ChainSpec<G, Forks<BlockNumber, Extension>>;
+//! pub type MyChainSpec2<G> = GenericChainSpec<G, Forks<BlockNumber, Extension>>;
 //! ```
 //!
 //! It's also possible to have a set of parameters that is allowed to change
@@ -84,7 +84,7 @@
 //!
 //! ```rust
 //! use serde::{Serialize, Deserialize};
-//! use sc_chain_spec::{Forks, ChainSpec, ChainSpecGroup, ChainSpecExtension};
+//! use sc_chain_spec::{Forks, GenericChainSpec, ChainSpecGroup, ChainSpecExtension};
 //!
 //! #[derive(Clone, Debug, Serialize, Deserialize, ChainSpecGroup)]
 //! pub struct ClientParams {
@@ -104,20 +104,48 @@
 //!		pub pool: Forks<u64, PoolParams>,
 //! }
 //!
-//! pub type MyChainSpec<G> = ChainSpec<G, Extension>;
+//! pub type MyChainSpec<G> = GenericChainSpec<G, Extension>;
 //! ```
 
 
 mod chain_spec;
 mod extension;
 
-pub use chain_spec::{ChainSpec, Properties, NoExtension};
-pub use extension::{Group, Fork, Forks, Extension};
+pub use chain_spec::{ChainSpec as GenericChainSpec, Properties, NoExtension};
+pub use extension::{Group, Fork, Forks, Extension, GetExtension, get_extension};
 pub use sc_chain_spec_derive::{ChainSpecExtension, ChainSpecGroup};
 
 use serde::{Serialize, de::DeserializeOwned};
 use sp_runtime::BuildStorage;
+use sc_network::Multiaddr;
+use sc_telemetry::TelemetryEndpoints;
 
 /// A set of traits for the runtime genesis config.
 pub trait RuntimeGenesis: Serialize + DeserializeOwned + BuildStorage {}
 impl<T: Serialize + DeserializeOwned + BuildStorage> RuntimeGenesis for T {}
+
+/// Common interface to `GenericChainSpec`
+pub trait ChainSpec: BuildStorage {
+	/// Spec name.
+	fn name(&self) -> &str;
+	/// Spec id.
+	fn id(&self) -> &str;
+	/// A list of bootnode addresses.
+	fn boot_nodes(&self) -> &[String];
+	/// Telemetry endpoints (if any)
+	fn telemetry_endpoints(&self) -> &Option<TelemetryEndpoints>;
+	/// Network protocol id.
+	fn protocol_id(&self) -> Option<&str>;
+	/// Additional loosly-typed properties of the chain.
+	///
+	/// Returns an empty JSON object if 'properties' not defined in config
+	fn properties(&self) -> Properties;
+	/// Returns a reference to defined chain spec extensions.
+	fn extensions(&self) -> &dyn GetExtension;
+	/// Add a bootnode to the list.
+	fn add_boot_node(&mut self, addr: Multiaddr);
+	/// Return spec as JSON.
+	fn as_json(&self, raw: bool) -> Result<String, String>;
+	/// Return StorageBuilder for this spec.
+	fn as_storage_builder(&self) -> &dyn BuildStorage;
+}

substrate/client/cli/src/commands/build_spec_cmd.rs

@@ -17,7 +17,7 @@
 use structopt::StructOpt;
 use log::info;
 use sc_network::config::build_multiaddr;
-use sc_service::{Configuration, ChainSpecExtension, RuntimeGenesis, ChainSpec};
+use sc_service::{Configuration, ChainSpec};
 
 use crate::error;
 use crate::VersionInfo;
@@ -49,16 +49,12 @@ pub struct BuildSpecCmd {
 
 impl BuildSpecCmd {
 	/// Run the build-spec command
-	pub fn run<G, E>(
+	pub fn run(
 		self,
-		config: Configuration<G, E>,
-	) -> error::Result<()>
-	where
-		G: RuntimeGenesis,
-		E: ChainSpecExtension,
-	{
+		config: Configuration,
+	) -> error::Result<()> {
 		info!("Building chain spec");
-		let mut spec = config.expect_chain_spec().clone();
+		let mut spec = config.chain_spec.expect("`chain_spec` is set to `Some` in `update_config`");
 		let raw_output = self.raw;
 
 		if spec.boot_nodes().is_empty() && !self.disable_default_bootnode {
@@ -72,7 +68,7 @@ impl BuildSpecCmd {
 			spec.add_boot_node(addr)
 		}
 
-		let json = sc_service::chain_ops::build_spec(spec, raw_output)?;
+		let json = sc_service::chain_ops::build_spec(&*spec, raw_output)?;
 
 		print!("{}", json);
 
@@ -80,15 +76,13 @@ impl BuildSpecCmd {
 	}
 
 	/// Update and prepare a `Configuration` with command line parameters
-	pub fn update_config<G, E, F>(
+	pub fn update_config<F>(
 		&self,
-		mut config: &mut Configuration<G, E>,
+		mut config: &mut Configuration,
 		spec_factory: F,
 		version: &VersionInfo,
 	) -> error::Result<()> where
-		G: RuntimeGenesis,
-		E: ChainSpecExtension,
-		F: FnOnce(&str) -> Result<Option<ChainSpec<G, E>>, String>,
+		F: FnOnce(&str) -> Result<Box<dyn ChainSpec>, String>,
 	{
 		self.shared_params.update_config(&mut config, spec_factory, version)?;
 

substrate/client/cli/src/commands/check_block_cmd.rs

@@ -18,7 +18,7 @@ use std::fmt::Debug;
 use std::str::FromStr;
 use structopt::StructOpt;
 use sc_service::{
-	Configuration, ChainSpecExtension, RuntimeGenesis, ServiceBuilderCommand, Roles, ChainSpec,
+	Configuration, ServiceBuilderCommand, Roles, ChainSpec,
 };
 use sp_runtime::traits::{Block as BlockT, Header as HeaderT};
 use sp_runtime::generic::BlockId;
@@ -53,15 +53,13 @@ pub struct CheckBlockCmd {
 
 impl CheckBlockCmd {
 	/// Run the check-block command
-	pub fn run<G, E, B, BC, BB>(
+	pub fn run<B, BC, BB>(
 		self,
-		config: Configuration<G, E>,
+		config: Configuration,
 		builder: B,
 	) -> error::Result<()>
 	where
-		B: FnOnce(Configuration<G, E>) -> Result<BC, sc_service::error::Error>,
-		G: RuntimeGenesis,
-		E: ChainSpecExtension,
+		B: FnOnce(Configuration) -> Result<BC, sc_service::error::Error>,
 		BC: ServiceBuilderCommand<Block = BB> + Unpin,
 		BB: sp_runtime::traits::Block + Debug,
 		<<<BB as BlockT>::Header as HeaderT>::Number as std::str::FromStr>::Err: std::fmt::Debug,
@@ -86,15 +84,13 @@ impl CheckBlockCmd {
 	}
 
 	/// Update and prepare a `Configuration` with command line parameters
-	pub fn update_config<G, E, F>(
+	pub fn update_config<F>(
 		&self,
-		mut config: &mut Configuration<G, E>,
+		mut config: &mut Configuration,
 		spec_factory: F,
 		version: &VersionInfo,
 	) -> error::Result<()> where
-		G: RuntimeGenesis,
-		E: ChainSpecExtension,
-		F: FnOnce(&str) -> Result<Option<ChainSpec<G, E>>, String>,
+		F: FnOnce(&str) -> Result<Box<dyn ChainSpec>, String>,
 	{
 		self.shared_params.update_config(&mut config, spec_factory, version)?;
 		self.import_params.update_config(&mut config, Roles::FULL, self.shared_params.dev)?;

substrate/client/cli/src/commands/export_blocks_cmd.rs

@@ -21,7 +21,7 @@ use std::fmt::Debug;
 use log::info;
 use structopt::StructOpt;
 use sc_service::{
-	Configuration, ChainSpecExtension, RuntimeGenesis, ServiceBuilderCommand, ChainSpec,
+	Configuration, ServiceBuilderCommand, ChainSpec,
 	config::DatabaseConfig, Roles,
 };
 use sp_runtime::traits::{Block as BlockT, Header as HeaderT};
@@ -65,15 +65,13 @@ pub struct ExportBlocksCmd {
 
 impl ExportBlocksCmd {
 	/// Run the export-blocks command
-	pub fn run<G, E, B, BC, BB>(
+	pub fn run<B, BC, BB>(
 		self,
-		config: Configuration<G, E>,
+		config: Configuration,
 		builder: B,
 	) -> error::Result<()>
 	where
-		B: FnOnce(Configuration<G, E>) -> Result<BC, sc_service::error::Error>,
-		G: RuntimeGenesis,
-		E: ChainSpecExtension,
+		B: FnOnce(Configuration) -> Result<BC, sc_service::error::Error>,
 		BC: ServiceBuilderCommand<Block = BB> + Unpin,
 		BB: sp_runtime::traits::Block + Debug,
 		<<<BB as BlockT>::Header as HeaderT>::Number as std::str::FromStr>::Err: std::fmt::Debug,
@@ -98,15 +96,13 @@ impl ExportBlocksCmd {
 	}
 
 	/// Update and prepare a `Configuration` with command line parameters
-	pub fn update_config<G, E, F>(
+	pub fn update_config<F>(
 		&self,
-		mut config: &mut Configuration<G, E>,
+		mut config: &mut Configuration,
 		spec_factory: F,
 		version: &VersionInfo,
 	) -> error::Result<()> where
-		G: RuntimeGenesis,
-		E: ChainSpecExtension,
-		F: FnOnce(&str) -> Result<Option<ChainSpec<G, E>>, String>,
+		F: FnOnce(&str) -> Result<Box<dyn ChainSpec>, String>,
 	{
 		self.shared_params.update_config(&mut config, spec_factory, version)?;
 		self.pruning_params.update_config(&mut config, Roles::FULL, true)?;

substrate/client/cli/src/commands/import_blocks_cmd.rs

@@ -20,7 +20,7 @@ use std::fs;
 use std::path::PathBuf;
 use structopt::StructOpt;
 use sc_service::{
-	Configuration, ChainSpecExtension, RuntimeGenesis, ServiceBuilderCommand, ChainSpec, Roles,
+	Configuration, ServiceBuilderCommand, ChainSpec, Roles,
 };
 use sp_runtime::traits::{Block as BlockT, Header as HeaderT};
 
@@ -59,15 +59,13 @@ impl<T: Read + Seek> ReadPlusSeek for T {}
 
 impl ImportBlocksCmd {
 	/// Run the import-blocks command
-	pub fn run<G, E, B, BC, BB>(
+	pub fn run<B, BC, BB>(
 		self,
-		config: Configuration<G, E>,
+		config: Configuration,
 		builder: B,
 	) -> error::Result<()>
 	where
-		B: FnOnce(Configuration<G, E>) -> Result<BC, sc_service::error::Error>,
-		G: RuntimeGenesis,
-		E: ChainSpecExtension,
+		B: FnOnce(Configuration) -> Result<BC, sc_service::error::Error>,
 		BC: ServiceBuilderCommand<Block = BB> + Unpin,
 		BB: sp_runtime::traits::Block + Debug,
 		<<<BB as BlockT>::Header as HeaderT>::Number as std::str::FromStr>::Err: std::fmt::Debug,
@@ -88,15 +86,13 @@ impl ImportBlocksCmd {
 	}
 
 	/// Update and prepare a `Configuration` with command line parameters
-	pub fn update_config<G, E, F>(
+	pub fn update_config<F>(
 		&self,
-		mut config: &mut Configuration<G, E>,
+		mut config: &mut Configuration,
 		spec_factory: F,
 		version: &VersionInfo,
 	) -> error::Result<()> where
-		G: RuntimeGenesis,
-		E: ChainSpecExtension,
-		F: FnOnce(&str) -> Result<Option<ChainSpec<G, E>>, String>,
+		F: FnOnce(&str) -> Result<Box<dyn ChainSpec>, String>,
 	{
 		self.shared_params.update_config(&mut config, spec_factory, version)?;
 		self.import_params.update_config(&mut config, Roles::FULL, self.shared_params.dev)?;

substrate/client/cli/src/commands/mod.rs

@@ -25,9 +25,7 @@ mod purge_chain_cmd;
 use std::fmt::Debug;
 use structopt::StructOpt;
 
-use sc_service::{
-	Configuration, ChainSpecExtension, RuntimeGenesis, ServiceBuilderCommand, ChainSpec,
-};
+use sc_service::{ Configuration, ServiceBuilderCommand, ChainSpec };
 use sp_runtime::traits::{Block as BlockT, Header as HeaderT};
 
 use crate::error;
@@ -87,15 +85,13 @@ impl Subcommand {
 	}
 
 	/// Run any `CoreParams` command
-	pub fn run<G, E, B, BC, BB>(
+	pub fn run<B, BC, BB>(
 		self,
-		config: Configuration<G, E>,
+		config: Configuration,
 		builder: B,
 	) -> error::Result<()>
 	where
-		B: FnOnce(Configuration<G, E>) -> Result<BC, sc_service::error::Error>,
-		G: RuntimeGenesis,
-		E: ChainSpecExtension,
+		B: FnOnce(Configuration) -> Result<BC, sc_service::error::Error>,
 		BC: ServiceBuilderCommand<Block = BB> + Unpin,
 		BB: sp_runtime::traits::Block + Debug,
 		<<<BB as BlockT>::Header as HeaderT>::Number as std::str::FromStr>::Err: std::fmt::Debug,
@@ -112,15 +108,13 @@ impl Subcommand {
 	}
 
 	/// Update and prepare a `Configuration` with command line parameters
-	pub fn update_config<G, E, F>(
+	pub fn update_config<F>(
 		&self,
-		mut config: &mut Configuration<G, E>,
+		mut config: &mut Configuration,
 		spec_factory: F,
 		version: &VersionInfo,
 	) -> error::Result<()> where
-		G: RuntimeGenesis,
-		E: ChainSpecExtension,
-		F: FnOnce(&str) -> Result<Option<ChainSpec<G, E>>, String>,
+		F: FnOnce(&str) -> Result<Box<dyn ChainSpec>, String>,
 	{
 		match self {
 			Subcommand::BuildSpec(cmd) => cmd.update_config(&mut config, spec_factory, version),

substrate/client/cli/src/commands/purge_chain_cmd.rs

@@ -18,10 +18,7 @@ use std::fmt::Debug;
 use std::io::{Write, self};
 use std::fs;
 use structopt::StructOpt;
-use sc_service::{
-	Configuration, ChainSpecExtension, RuntimeGenesis, ChainSpec,
-	config::{DatabaseConfig},
-};
+use sc_service::{ Configuration, ChainSpec, config::{DatabaseConfig} };
 
 use crate::error;
 use crate::VersionInfo;
@@ -41,14 +38,10 @@ pub struct PurgeChainCmd {
 
 impl PurgeChainCmd {
 	/// Run the purge command
-	pub fn run<G, E>(
+	pub fn run(
 		self,
-		config: Configuration<G, E>,
-	) -> error::Result<()>
-	where
-		G: RuntimeGenesis,
-		E: ChainSpecExtension,
-	{
+		config: Configuration,
+	) -> error::Result<()> {
 		let db_path = match config.expect_database() {
 			DatabaseConfig::Path { path, .. } => path,
 			_ => {
@@ -88,15 +81,13 @@ impl PurgeChainCmd {
 	}
 
 	/// Update and prepare a `Configuration` with command line parameters
-	pub fn update_config<G, E, F>(
+	pub fn update_config<F>(
 		&self,
-		mut config: &mut Configuration<G, E>,
+		mut config: &mut Configuration,
 		spec_factory: F,
 		version: &VersionInfo,
 	) -> error::Result<()> where
-		G: RuntimeGenesis,
-		E: ChainSpecExtension,
-		F: FnOnce(&str) -> Result<Option<ChainSpec<G, E>>, String>,
+		F: FnOnce(&str) -> Result<Box<dyn ChainSpec>, String>,
 	{
 		self.shared_params.update_config(&mut config, spec_factory, version)?;
 		config.use_in_memory_keystore()?;

substrate/client/cli/src/commands/revert_cmd.rs

@@ -17,7 +17,7 @@
 use std::fmt::Debug;
 use structopt::StructOpt;
 use sc_service::{
-	Configuration, ChainSpecExtension, RuntimeGenesis, ServiceBuilderCommand, ChainSpec, Roles,
+	Configuration, ServiceBuilderCommand, ChainSpec, Roles,
 };
 use sp_runtime::traits::{Block as BlockT, Header as HeaderT};
 
@@ -43,15 +43,13 @@ pub struct RevertCmd {
 
 impl RevertCmd {
 	/// Run the revert command
-	pub fn run<G, E, B, BC, BB>(
+	pub fn run<B, BC, BB>(
 		self,
-		config: Configuration<G, E>,
+		config: Configuration,
 		builder: B,
 	) -> error::Result<()>
 	where
-		B: FnOnce(Configuration<G, E>) -> Result<BC, sc_service::error::Error>,
-		G: RuntimeGenesis,
-		E: ChainSpecExtension,
+		B: FnOnce(Configuration) -> Result<BC, sc_service::error::Error>,
 		BC: ServiceBuilderCommand<Block = BB> + Unpin,
 		BB: sp_runtime::traits::Block + Debug,
 		<<<BB as BlockT>::Header as HeaderT>::Number as std::str::FromStr>::Err: std::fmt::Debug,
@@ -64,15 +62,13 @@ impl RevertCmd {
 	}
 
 	/// Update and prepare a `Configuration` with command line parameters
-	pub fn update_config<G, E, F>(
+	pub fn update_config<F>(
 		&self,
-		mut config: &mut Configuration<G, E>,
+		mut config: &mut Configuration,
 		spec_factory: F,
 		version: &VersionInfo,
 	) -> error::Result<()> where
-		G: RuntimeGenesis,
-		E: ChainSpecExtension,
-		F: FnOnce(&str) -> Result<Option<ChainSpec<G, E>>, String>,
+		F: FnOnce(&str) -> Result<Box<dyn ChainSpec>, String>,
 	{
 		self.shared_params.update_config(&mut config, spec_factory, version)?;
 		self.pruning_params.update_config(&mut config, Roles::FULL, true)?;

substrate/client/cli/src/commands/runcmd.rs

@@ -23,7 +23,7 @@ use names::{Generator, Name};
 use regex::Regex;
 use chrono::prelude::*;
 use sc_service::{
-	AbstractService, Configuration, ChainSpecExtension, RuntimeGenesis, ChainSpec, Roles,
+	AbstractService, Configuration, ChainSpec, Roles,
 	config::{KeystoreConfig, PrometheusConfig},
 };
 use sc_telemetry::TelemetryEndpoints;
@@ -291,16 +291,14 @@ impl RunCmd {
 	}
 
 	/// Update and prepare a `Configuration` with command line parameters of `RunCmd` and `VersionInfo`
-	pub fn update_config<G, E, F>(
+	pub fn update_config<F>(
 		&self,
-		mut config: &mut Configuration<G, E>,
+		mut config: &mut Configuration,
 		spec_factory: F,
 		version: &VersionInfo,
 	) -> error::Result<()>
 	where
-		G: RuntimeGenesis,
-		E: ChainSpecExtension,
-		F: FnOnce(&str) -> Result<Option<ChainSpec<G, E>>, String>,
+		F: FnOnce(&str) -> Result<Box<dyn ChainSpec>, String>,
 	{
 		self.shared_params.update_config(&mut config, spec_factory, version)?;
 
@@ -447,18 +445,16 @@ impl RunCmd {
 	}
 
 	/// Run the command that runs the node
-	pub fn run<G, E, FNL, FNF, SL, SF>(
+	pub fn run<FNL, FNF, SL, SF>(
 		self,
-		config: Configuration<G, E>,
+		config: Configuration,
 		new_light: FNL,
 		new_full: FNF,
 		version: &VersionInfo,
 	) -> error::Result<()>
 	where
-		G: RuntimeGenesis,
-		E: ChainSpecExtension,
-		FNL: FnOnce(Configuration<G, E>) -> Result<SL, sc_service::error::Error>,
-		FNF: FnOnce(Configuration<G, E>) -> Result<SF, sc_service::error::Error>,
+		FNL: FnOnce(Configuration) -> Result<SL, sc_service::error::Error>,
+		FNF: FnOnce(Configuration) -> Result<SF, sc_service::error::Error>,
 		SL: AbstractService + Unpin,
 		SF: AbstractService + Unpin,
 	{
@@ -625,7 +621,7 @@ fn parse_cors(s: &str) -> Result<Cors, Box<dyn std::error::Error>> {
 #[cfg(test)]
 mod tests {
 	use super::*;
-	use sc_service::config::DatabaseConfig;
+	use sc_service::{GenericChainSpec, config::DatabaseConfig};
 
 	const TEST_VERSION_INFO: &'static VersionInfo = &VersionInfo {
 		name: "node-test",
@@ -655,7 +651,7 @@ mod tests {
 
 	#[test]
 	fn keystore_path_is_generated_correctly() {
-		let chain_spec = ChainSpec::from_genesis(
+		let chain_spec = GenericChainSpec::from_genesis(
 			"test",
 			"test-id",
 			|| (),
@@ -673,9 +669,9 @@ mod tests {
 
 			let mut config = Configuration::default();
 			config.config_dir = Some(PathBuf::from("/test/path"));
-			config.chain_spec = Some(chain_spec.clone());
+			config.chain_spec = Some(Box::new(chain_spec.clone()));
 			let chain_spec = chain_spec.clone();
-			cli.update_config(&mut config, move |_| Ok(Some(chain_spec)), TEST_VERSION_INFO).unwrap();
+			cli.update_config(&mut config, move |_| Ok(Box::new(chain_spec)), TEST_VERSION_INFO).unwrap();
 
 			let expected_path = match keystore_path {
 				Some(path) => PathBuf::from(path),
@@ -688,7 +684,7 @@ mod tests {
 
 	#[test]
 	fn ensure_load_spec_provide_defaults() {
-		let chain_spec = ChainSpec::from_genesis(
+		let chain_spec = GenericChainSpec::from_genesis(
 			"test",
 			"test-id",
 			|| (),
@@ -703,7 +699,7 @@ mod tests {
 		let cli = RunCmd::from_iter(args);
 
 		let mut config = Configuration::from_version(TEST_VERSION_INFO);
-		cli.update_config(&mut config, |_| Ok(Some(chain_spec)), TEST_VERSION_INFO).unwrap();
+		cli.update_config(&mut config, |_| Ok(Box::new(chain_spec)), TEST_VERSION_INFO).unwrap();
 
 		assert!(config.chain_spec.is_some());
 		assert!(!config.network.boot_nodes.is_empty());
@@ -712,7 +708,7 @@ mod tests {
 
 	#[test]
 	fn ensure_update_config_for_running_node_provides_defaults() {
-		let chain_spec = ChainSpec::from_genesis(
+		let chain_spec = GenericChainSpec::from_genesis(
 			"test",
 			"test-id",
 			|| (),
@@ -728,7 +724,7 @@ mod tests {
 
 		let mut config = Configuration::from_version(TEST_VERSION_INFO);
 		cli.init(&TEST_VERSION_INFO).unwrap();
-		cli.update_config(&mut config, |_| Ok(Some(chain_spec)), TEST_VERSION_INFO).unwrap();
+		cli.update_config(&mut config, |_| Ok(Box::new(chain_spec)), TEST_VERSION_INFO).unwrap();
 
 		assert!(config.config_dir.is_some());
 		assert!(config.database.is_some());

substrate/client/cli/src/params/import_params.rs

@@ -15,7 +15,7 @@
 // along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
 
 use structopt::StructOpt;
-use sc_service::{Configuration, RuntimeGenesis, config::DatabaseConfig};
+use sc_service::{Configuration, config::DatabaseConfig};
 
 use crate::error;
 use crate::arg_enums::{
@@ -79,15 +79,12 @@ pub struct ImportParams {
 
 impl ImportParams {
 	/// Put block import CLI params into `config` object.
-	pub fn update_config<G, E>(
+	pub fn update_config(
 		&self,
-		mut config: &mut Configuration<G, E>,
+		mut config: &mut Configuration,
 		role: sc_service::Roles,
 		is_dev: bool,
-	) -> error::Result<()>
-	where
-		G: RuntimeGenesis,
-	{
+	) -> error::Result<()> {
 		use sc_client_api::execution_extensions::ExecutionStrategies;
 
 		if let Some(DatabaseConfig::Path { ref mut cache_size, .. }) = config.database {

substrate/client/cli/src/params/network_configuration_params.rs

@@ -21,7 +21,7 @@ use structopt::StructOpt;
 use sc_network::{
 	config::{NonReservedPeerMode, TransportConfig}, multiaddr::Protocol,
 };
-use sc_service::{Configuration, RuntimeGenesis};
+use sc_service::Configuration;
 
 use crate::error;
 use crate::params::node_key_params::NodeKeyParams;
@@ -101,16 +101,13 @@ pub struct NetworkConfigurationParams {
 
 impl NetworkConfigurationParams {
 	/// Fill the given `NetworkConfiguration` by looking at the cli parameters.
-	pub fn update_config<G, E>(
+	pub fn update_config(
 		&self,
-		mut config: &mut Configuration<G, E>,
+		mut config: &mut Configuration,
 		config_path: PathBuf,
 		client_id: String,
 		is_dev: bool,
-	) -> error::Result<()>
-	where
-		G: RuntimeGenesis,
-	{
+	) -> error::Result<()> {
 		config.network.boot_nodes.extend(self.bootnodes.clone());
 		config.network.config_path = Some(config_path.clone());
 		config.network.net_config_path = Some(config_path.clone());

substrate/client/cli/src/params/node_key_params.rs

@@ -16,7 +16,7 @@
 
 use std::{path::PathBuf, str::FromStr};
 use structopt::StructOpt;
-use sc_service::{Configuration, RuntimeGenesis};
+use sc_service::Configuration;
 use sc_network::config::NodeKeyConfig;
 use sp_core::H256;
 
@@ -93,14 +93,11 @@ pub struct NodeKeyParams {
 impl NodeKeyParams {
 	/// Create a `NodeKeyConfig` from the given `NodeKeyParams` in the context
 	/// of an optional network config storage directory.
-	pub fn update_config<'a, G, E>(
+	pub fn update_config<'a>(
 		&self,
-		mut config: &'a mut Configuration<G, E>,
+		mut config: &'a mut Configuration,
 		net_config_path: Option<&PathBuf>,
-	) -> error::Result<&'a NodeKeyConfig>
-	where
-		G: RuntimeGenesis,
-	{
+	) -> error::Result<&'a NodeKeyConfig> {
 		config.network.node_key = match self.node_key_type {
 			NodeKeyType::Ed25519 => {
 				let secret = if let Some(node_key) = self.node_key.as_ref() {
@@ -146,7 +143,7 @@ mod tests {
 	fn test_node_key_config_input() {
 		fn secret_input(net_config_dir: Option<&PathBuf>) -> error::Result<()> {
 			NodeKeyType::variants().iter().try_for_each(|t| {
-				let mut config = Configuration::<(), ()>::default();
+				let mut config = Configuration::default();
 				let node_key_type = NodeKeyType::from_str(t).unwrap();
 				let sk = match node_key_type {
 					NodeKeyType::Ed25519 => ed25519::SecretKey::generate().as_ref().to_vec()
@@ -173,7 +170,7 @@ mod tests {
 	fn test_node_key_config_file() {
 		fn secret_file(net_config_dir: Option<&PathBuf>) -> error::Result<()> {
 			NodeKeyType::variants().iter().try_for_each(|t| {
-				let mut config = Configuration::<(), ()>::default();
+				let mut config = Configuration::default();
 				let node_key_type = NodeKeyType::from_str(t).unwrap();
 				let tmp = tempfile::Builder::new().prefix("alice").tempdir()?;
 				let file = tmp.path().join(format!("{}_mysecret", t)).to_path_buf();
@@ -212,7 +209,7 @@ mod tests {
 
 		fn no_config_dir() -> error::Result<()> {
 			with_def_params(|params| {
-				let mut config = Configuration::<(), ()>::default();
+				let mut config = Configuration::default();
 				let typ = params.node_key_type;
 				params.update_config(&mut config, None)
 					.and_then(|c| match c {
@@ -225,7 +222,7 @@ mod tests {
 
 		fn some_config_dir(net_config_dir: &PathBuf) -> error::Result<()> {
 			with_def_params(|params| {
-				let mut config = Configuration::<(), ()>::default();
+				let mut config = Configuration::default();
 				let dir = PathBuf::from(net_config_dir.clone());
 				let typ = params.node_key_type;
 				params.update_config(&mut config, Some(net_config_dir))

substrate/client/cli/src/params/pruning_params.rs

@@ -15,7 +15,7 @@
 // along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
 
 use structopt::StructOpt;
-use sc_service::{Configuration, RuntimeGenesis, PruningMode};
+use sc_service::{Configuration, PruningMode};
 
 use crate::error;
 
@@ -33,15 +33,12 @@ pub struct PruningParams {
 
 impl PruningParams {
 	/// Put block pruning CLI params into `config` object.
-	pub fn update_config<G, E>(
+	pub fn update_config(
 		&self,
-		mut config: &mut Configuration<G, E>,
+		mut config: &mut Configuration,
 		role: sc_service::Roles,
 		unsafe_pruning: bool,
-	) -> error::Result<()>
-	where
-		G: RuntimeGenesis,
-	{
+	) -> error::Result<()> {
 		// by default we disable pruning if the node is an authority (i.e.
 		// `ArchiveAll`), otherwise we keep state for the last 256 blocks. if the
 		// node is an authority and pruning is enabled explicitly, then we error

substrate/client/cli/src/params/shared_params.rs

@@ -18,8 +18,7 @@ use std::path::PathBuf;
 use structopt::StructOpt;
 use app_dirs::{AppInfo, AppDataType};
 use sc_service::{
-	Configuration, ChainSpecExtension, RuntimeGenesis,
-	config::DatabaseConfig, ChainSpec,
+	Configuration, config::DatabaseConfig, ChainSpec,
 };
 
 use crate::VersionInfo;
@@ -50,25 +49,19 @@ pub struct SharedParams {
 
 impl SharedParams {
 	/// Load spec to `Configuration` from `SharedParams` and spec factory.
-	pub fn update_config<'a, G, E, F>(
+	pub fn update_config<'a, F>(
 		&self,
-		mut config: &'a mut Configuration<G, E>,
+		mut config: &'a mut Configuration,
 		spec_factory: F,
 		version: &VersionInfo,
-	) -> error::Result<&'a ChainSpec<G, E>> where
-		G: RuntimeGenesis,
-		E: ChainSpecExtension,
-		F: FnOnce(&str) -> Result<Option<ChainSpec<G, E>>, String>,
+	) -> error::Result<&'a dyn ChainSpec> where
+		F: FnOnce(&str) -> Result<Box<dyn ChainSpec>, String>,
 	{
 		let chain_key = match self.chain {
 			Some(ref chain) => chain.clone(),
 			None => if self.dev { "dev".into() } else { "".into() }
 		};
-		let spec = match spec_factory(&chain_key)? {
-			Some(spec) => spec,
-			None => ChainSpec::from_json_file(PathBuf::from(chain_key))?
-		};
-
+		let spec = spec_factory(&chain_key)?;
 		config.network.boot_nodes = spec.boot_nodes().to_vec();
 		config.telemetry_endpoints = spec.telemetry_endpoints().clone();
 
@@ -87,7 +80,7 @@ impl SharedParams {
 			});
 		}
 
-		Ok(config.chain_spec.as_ref().unwrap())
+		Ok(config.expect_chain_spec())
 	}
 
 	/// Initialize substrate. This must be done only once.

substrate/client/cli/src/params/transaction_pool_params.rs

@@ -31,9 +31,9 @@ pub struct TransactionPoolParams {
 
 impl TransactionPoolParams {
 	/// Fill the given `PoolConfiguration` by looking at the cli parameters.
-	pub fn update_config<G, E>(
+	pub fn update_config(
 		&self,
-		config: &mut Configuration<G, E>,
+		config: &mut Configuration,
 	) -> error::Result<()> {
 		// ready queue
 		config.transaction_pool.ready.count = self.pool_limit;

substrate/client/cli/src/runtime.rs

@@ -79,12 +79,12 @@ fn build_runtime() -> Result<tokio::runtime::Runtime, std::io::Error> {
 
 /// A helper function that runs a future with tokio and stops if the process receives the signal
 /// SIGTERM or SIGINT
-pub fn run_until_exit<FUT, ERR, G, E, F>(
-	mut config: Configuration<G, E>,
+pub fn run_until_exit<FUT, ERR, F>(
+	mut config: Configuration,
 	future_builder: F,
 ) -> error::Result<()>
 where
-	F: FnOnce(Configuration<G, E>) -> error::Result<FUT>,
+	F: FnOnce(Configuration) -> error::Result<FUT>,
 	FUT: Future<Output = Result<(), ERR>> + future::Future,
 	ERR: 'static + std::error::Error,
 {
@@ -106,12 +106,12 @@ where
 
 /// A helper function that runs an `AbstractService` with tokio and stops if the process receives
 /// the signal SIGTERM or SIGINT
-pub fn run_service_until_exit<T, G, E, F>(
-	mut config: Configuration<G, E>,
+pub fn run_service_until_exit<T, F>(
+	mut config: Configuration,
 	service_builder: F,
 ) -> error::Result<()>
 where
-	F: FnOnce(Configuration<G, E>) -> Result<T, sc_service::error::Error>,
+	F: FnOnce(Configuration) -> Result<T, sc_service::error::Error>,
 	T: AbstractService + Unpin,
 {
 	let mut runtime = build_runtime()?;

substrate/client/db/src/lib.rs

@@ -285,10 +285,10 @@ pub enum DatabaseSettingsSrc {
 }
 
 /// Create an instance of db-backed client.
-pub fn new_client<E, S, Block, RA>(
+pub fn new_client<E, Block, RA>(
 	settings: DatabaseSettings,
 	executor: E,
-	genesis_storage: &S,
+	genesis_storage: &dyn BuildStorage,
 	fork_blocks: ForkBlocks<Block>,
 	bad_blocks: BadBlocks<Block>,
 	execution_extensions: ExecutionExtensions<Block>,
@@ -307,7 +307,6 @@ pub fn new_client<E, S, Block, RA>(
 	where
 		Block: BlockT,
 		E: CodeExecutor + RuntimeInfo,
-		S: BuildStorage,
 {
 	let backend = Arc::new(Backend::new(settings, CANONICALIZATION_DELAY)?);
 	let executor = sc_client::LocalCallExecutor::new(backend.clone(), executor);

substrate/client/service/src/builder.rs

@@ -26,7 +26,7 @@ use sc_client_api::{
 	ExecutorProvider, CallExecutor
 };
 use sc_client::Client;
-use sc_chain_spec::{RuntimeGenesis, Extension};
+use sc_chain_spec::get_extension;
 use sp_consensus::import_queue::ImportQueue;
 use futures::{
 	Future, FutureExt, StreamExt,
@@ -119,10 +119,10 @@ pub type BackgroundTask = Pin<Box<dyn Future<Output=()> + Send>>;
 /// The order in which the `with_*` methods are called doesn't matter, as the correct binding of
 /// generics is done when you call `build`.
 ///
-pub struct ServiceBuilder<TBl, TRtApi, TGen, TCSExt, TCl, TFchr, TSc, TImpQu, TFprb, TFpp,
+pub struct ServiceBuilder<TBl, TRtApi, TCl, TFchr, TSc, TImpQu, TFprb, TFpp,
 	TExPool, TRpc, Backend>
 {
-	config: Configuration<TGen, TCSExt>,
+	config: Configuration,
 	pub (crate) client: Arc<TCl>,
 	backend: Arc<Backend>,
 	tasks_builder: TaskManagerBuilder,
@@ -193,24 +193,20 @@ type TFullParts<TBl, TRtApi, TExecDisp> = (
 );
 
 /// Creates a new full client for the given config.
-pub fn new_full_client<TBl, TRtApi, TExecDisp, TGen, TCSExt>(
-	config: &Configuration<TGen, TCSExt>,
+pub fn new_full_client<TBl, TRtApi, TExecDisp>(
+	config: &Configuration,
 ) -> Result<TFullClient<TBl, TRtApi, TExecDisp>, Error> where
 	TBl: BlockT,
 	TExecDisp: NativeExecutionDispatch + 'static,
-	TGen: sp_runtime::BuildStorage + serde::Serialize + for<'de> serde::Deserialize<'de>,
-	TCSExt: Extension,
 {
 	new_full_parts(config).map(|parts| parts.0)
 }
 
-fn new_full_parts<TBl, TRtApi, TExecDisp, TGen, TCSExt>(
-	config: &Configuration<TGen, TCSExt>,
+fn new_full_parts<TBl, TRtApi, TExecDisp>(
+	config: &Configuration,
 ) -> Result<TFullParts<TBl, TRtApi, TExecDisp>,	Error> where
 	TBl: BlockT,
 	TExecDisp: NativeExecutionDispatch + 'static,
-	TGen: sp_runtime::BuildStorage + serde::Serialize + for<'de> serde::Deserialize<'de>,
-	TCSExt: Extension,
 {
 	let keystore = match &config.keystore {
 		KeystoreConfig::Path { path, password } => Keystore::open(
@@ -230,15 +226,11 @@ fn new_full_parts<TBl, TRtApi, TExecDisp, TGen, TCSExt>(
 	);
 
 	let chain_spec = config.expect_chain_spec();
-	let fork_blocks = chain_spec
-		.extensions()
-		.get::<sc_client::ForkBlocks<TBl>>()
+	let fork_blocks = get_extension::<sc_client::ForkBlocks<TBl>>(chain_spec.extensions())
 		.cloned()
 		.unwrap_or_default();
 
-	let bad_blocks = chain_spec
-		.extensions()
-		.get::<sc_client::BadBlocks<TBl>>()
+	let bad_blocks = get_extension::<sc_client::BadBlocks<TBl>>(chain_spec.extensions())
 		.cloned()
 		.unwrap_or_default();
 
@@ -267,7 +259,7 @@ fn new_full_parts<TBl, TRtApi, TExecDisp, TGen, TCSExt>(
 		sc_client_db::new_client(
 			db_config,
 			executor,
-			config.expect_chain_spec(),
+			config.expect_chain_spec().as_storage_builder(),
 			fork_blocks,
 			bad_blocks,
 			extensions,
@@ -278,16 +270,13 @@ fn new_full_parts<TBl, TRtApi, TExecDisp, TGen, TCSExt>(
 	Ok((client, backend, keystore, tasks_builder))
 }
 
-impl<TGen, TCSExt> ServiceBuilder<(), (), TGen, TCSExt, (), (), (), (), (), (), (), (), ()>
-where TGen: RuntimeGenesis, TCSExt: Extension {
+impl ServiceBuilder<(), (), (), (), (), (), (), (), (), (), ()> {
 	/// Start the service builder with a configuration.
 	pub fn new_full<TBl: BlockT, TRtApi, TExecDisp: NativeExecutionDispatch + 'static>(
-		config: Configuration<TGen, TCSExt>
+		config: Configuration,
 	) -> Result<ServiceBuilder<
 		TBl,
 		TRtApi,
-		TGen,
-		TCSExt,
 		TFullClient<TBl, TRtApi, TExecDisp>,
 		Arc<OnDemand<TBl>>,
 		(),
@@ -323,12 +312,10 @@ where TGen: RuntimeGenesis, TCSExt: Extension {
 
 	/// Start the service builder with a configuration.
 	pub fn new_light<TBl: BlockT, TRtApi, TExecDisp: NativeExecutionDispatch + 'static>(
-		config: Configuration<TGen, TCSExt>
+		config: Configuration,
 	) -> Result<ServiceBuilder<
 		TBl,
 		TRtApi,
-		TGen,
-		TCSExt,
 		TLightClient<TBl, TRtApi, TExecDisp>,
 		Arc<OnDemand<TBl>>,
 		(),
@@ -386,7 +373,7 @@ where TGen: RuntimeGenesis, TCSExt: Extension {
 		let remote_blockchain = backend.remote_blockchain();
 		let client = Arc::new(sc_client::light::new_light(
 			backend.clone(),
-			config.expect_chain_spec(),
+			config.expect_chain_spec().as_storage_builder(),
 			executor,
 			config.prometheus_config.as_ref().map(|config| config.registry.clone()),
 		)?);
@@ -411,8 +398,8 @@ where TGen: RuntimeGenesis, TCSExt: Extension {
 	}
 }
 
-impl<TBl, TRtApi, TGen, TCSExt, TCl, TFchr, TSc, TImpQu, TFprb, TFpp, TExPool, TRpc, Backend>
-	ServiceBuilder<TBl, TRtApi, TGen, TCSExt, TCl, TFchr, TSc, TImpQu, TFprb, TFpp,
+impl<TBl, TRtApi, TCl, TFchr, TSc, TImpQu, TFprb, TFpp, TExPool, TRpc, Backend>
+	ServiceBuilder<TBl, TRtApi, TCl, TFchr, TSc, TImpQu, TFprb, TFpp,
 	 	TExPool, TRpc, Backend> {
 
 	/// Returns a reference to the client that was stored in this builder.
@@ -458,9 +445,9 @@ impl<TBl, TRtApi, TGen, TCSExt, TCl, TFchr, TSc, TImpQu, TFprb, TFpp, TExPool, T
 	pub fn with_opt_select_chain<USc>(
 		self,
 		select_chain_builder: impl FnOnce(
-			&Configuration<TGen, TCSExt>, &Arc<Backend>
+			&Configuration, &Arc<Backend>,
 		) -> Result<Option<USc>, Error>
-	) -> Result<ServiceBuilder<TBl, TRtApi, TGen, TCSExt, TCl, TFchr, USc, TImpQu, TFprb, TFpp,
+	) -> Result<ServiceBuilder<TBl, TRtApi, TCl, TFchr, USc, TImpQu, TFprb, TFpp,
 		TExPool, TRpc, Backend>, Error> {
 		let select_chain = select_chain_builder(&self.config, &self.backend)?;
 
@@ -486,8 +473,8 @@ impl<TBl, TRtApi, TGen, TCSExt, TCl, TFchr, TSc, TImpQu, TFprb, TFpp, TExPool, T
 	/// Defines which head-of-chain strategy to use.
 	pub fn with_select_chain<USc>(
 		self,
-		builder: impl FnOnce(&Configuration<TGen, TCSExt>, &Arc<Backend>) -> Result<USc, Error>
-	) -> Result<ServiceBuilder<TBl, TRtApi, TGen, TCSExt, TCl, TFchr, USc, TImpQu, TFprb, TFpp,
+		builder: impl FnOnce(&Configuration, &Arc<Backend>) -> Result<USc, Error>,
+	) -> Result<ServiceBuilder<TBl, TRtApi, TCl, TFchr, USc, TImpQu, TFprb, TFpp,
 		TExPool, TRpc, Backend>, Error> {
 		self.with_opt_select_chain(|cfg, b| builder(cfg, b).map(Option::Some))
 	}
@@ -495,9 +482,9 @@ impl<TBl, TRtApi, TGen, TCSExt, TCl, TFchr, TSc, TImpQu, TFprb, TFpp, TExPool, T
 	/// Defines which import queue to use.
 	pub fn with_import_queue<UImpQu>(
 		self,
-		builder: impl FnOnce(&Configuration<TGen, TCSExt>, Arc<TCl>, Option<TSc>, Arc<TExPool>)
+		builder: impl FnOnce(&Configuration, Arc<TCl>, Option<TSc>, Arc<TExPool>)
 			-> Result<UImpQu, Error>
-	) -> Result<ServiceBuilder<TBl, TRtApi, TGen, TCSExt, TCl, TFchr, TSc, UImpQu, TFprb, TFpp,
+	) -> Result<ServiceBuilder<TBl, TRtApi, TCl, TFchr, TSc, UImpQu, TFprb, TFpp,
 			TExPool, TRpc, Backend>, Error>
 	where TSc: Clone {
 		let import_queue = builder(
@@ -533,8 +520,6 @@ impl<TBl, TRtApi, TGen, TCSExt, TCl, TFchr, TSc, TImpQu, TFprb, TFpp, TExPool, T
 	) -> Result<ServiceBuilder<
 		TBl,
 		TRtApi,
-		TGen,
-		TCSExt,
 		TCl,
 		TFchr,
 		TSc,
@@ -573,8 +558,6 @@ impl<TBl, TRtApi, TGen, TCSExt, TCl, TFchr, TSc, TImpQu, TFprb, TFpp, TExPool, T
 	) -> Result<ServiceBuilder<
 		TBl,
 		TRtApi,
-		TGen,
-		TCSExt,
 		TCl,
 		TFchr,
 		TSc,
@@ -592,14 +575,14 @@ impl<TBl, TRtApi, TGen, TCSExt, TCl, TFchr, TSc, TImpQu, TFprb, TFpp, TExPool, T
 	pub fn with_import_queue_and_opt_fprb<UImpQu, UFprb>(
 		self,
 		builder: impl FnOnce(
-			&Configuration<TGen, TCSExt>,
+			&Configuration,
 			Arc<TCl>,
 			Arc<Backend>,
 			Option<TFchr>,
 			Option<TSc>,
 			Arc<TExPool>,
 		) -> Result<(UImpQu, Option<UFprb>), Error>
-	) -> Result<ServiceBuilder<TBl, TRtApi, TGen, TCSExt, TCl, TFchr, TSc, UImpQu, UFprb, TFpp,
+	) -> Result<ServiceBuilder<TBl, TRtApi, TCl, TFchr, TSc, UImpQu, UFprb, TFpp,
 		TExPool, TRpc, Backend>, Error>
 	where TSc: Clone, TFchr: Clone {
 		let (import_queue, fprb) = builder(
@@ -634,14 +617,14 @@ impl<TBl, TRtApi, TGen, TCSExt, TCl, TFchr, TSc, TImpQu, TFprb, TFpp, TExPool, T
 	pub fn with_import_queue_and_fprb<UImpQu, UFprb>(
 		self,
 		builder: impl FnOnce(
-			&Configuration<TGen, TCSExt>,
+			&Configuration,
 			Arc<TCl>,
 			Arc<Backend>,
 			Option<TFchr>,
 			Option<TSc>,
 			Arc<TExPool>,
 		) -> Result<(UImpQu, UFprb), Error>
-	) -> Result<ServiceBuilder<TBl, TRtApi, TGen, TCSExt, TCl, TFchr, TSc, UImpQu, UFprb, TFpp,
+	) -> Result<ServiceBuilder<TBl, TRtApi, TCl, TFchr, TSc, UImpQu, UFprb, TFpp,
 			TExPool, TRpc, Backend>, Error>
 	where TSc: Clone, TFchr: Clone {
 		self.with_import_queue_and_opt_fprb(|cfg, cl, b, f, sc, tx|
@@ -658,7 +641,7 @@ impl<TBl, TRtApi, TGen, TCSExt, TCl, TFchr, TSc, TImpQu, TFprb, TFpp, TExPool, T
 			Arc<TCl>,
 			Option<TFchr>,
 		) -> Result<(UExPool, Option<BackgroundTask>), Error>
-	) -> Result<ServiceBuilder<TBl, TRtApi, TGen, TCSExt, TCl, TFchr, TSc, TImpQu, TFprb, TFpp,
+	) -> Result<ServiceBuilder<TBl, TRtApi, TCl, TFchr, TSc, TImpQu, TFprb, TFpp,
 		UExPool, TRpc, Backend>, Error>
 	where TSc: Clone, TFchr: Clone {
 		let (transaction_pool, background_task) = transaction_pool_builder(
@@ -694,7 +677,7 @@ impl<TBl, TRtApi, TGen, TCSExt, TCl, TFchr, TSc, TImpQu, TFprb, TFpp, TExPool, T
 	pub fn with_rpc_extensions<URpc>(
 		self,
 		rpc_ext_builder: impl FnOnce(&Self) -> Result<URpc, Error>,
-	) -> Result<ServiceBuilder<TBl, TRtApi, TGen, TCSExt, TCl, TFchr, TSc, TImpQu, TFprb, TFpp,
+	) -> Result<ServiceBuilder<TBl, TRtApi, TCl, TFchr, TSc, TImpQu, TFprb, TFpp,
 		TExPool, URpc, Backend>, Error>
 	where TSc: Clone, TFchr: Clone {
 		let rpc_extensions = rpc_ext_builder(&self)?;
@@ -755,12 +738,10 @@ pub trait ServiceBuilderCommand {
 	) -> Pin<Box<dyn Future<Output = Result<(), Error>> + Send>>;
 }
 
-impl<TBl, TRtApi, TGen, TCSExt, TBackend, TExec, TSc, TImpQu, TExPool, TRpc>
+impl<TBl, TRtApi, TBackend, TExec, TSc, TImpQu, TExPool, TRpc>
 ServiceBuilder<
 	TBl,
 	TRtApi,
-	TGen,
-	TCSExt,
 	Client<TBackend, TExec, TBl, TRtApi>,
 	Arc<OnDemand<TBl>>,
 	TSc,
@@ -781,8 +762,6 @@ ServiceBuilder<
 		sp_api::ApiExt<TBl, StateBackend = TBackend::State>,
 	TBl: BlockT,
 	TRtApi: 'static + Send + Sync,
-	TGen: RuntimeGenesis,
-	TCSExt: Extension,
 	TBackend: 'static + sc_client_api::backend::Backend<TBl> + Send,
 	TExec: 'static + sc_client::CallExecutor<TBl> + Send + Sync + Clone,
 	TSc: Clone,

substrate/client/service/src/chain_ops.rs

@@ -19,7 +19,7 @@
 use crate::error;
 use crate::builder::{ServiceBuilderCommand, ServiceBuilder};
 use crate::error::Error;
-use sc_chain_spec::{ChainSpec, RuntimeGenesis, Extension};
+use sc_chain_spec::ChainSpec;
 use log::{warn, info};
 use futures::{future, prelude::*};
 use sp_runtime::traits::{
@@ -38,19 +38,16 @@ use std::{io::{Read, Write, Seek}, pin::Pin};
 use sc_client_api::BlockBody;
 
 /// Build a chain spec json
-pub fn build_spec<G, E>(spec: ChainSpec<G, E>, raw: bool) -> error::Result<String> where
-	G: RuntimeGenesis,
-	E: Extension,
-{
-	Ok(spec.to_json(raw)?)
+pub fn build_spec(spec: &dyn ChainSpec, raw: bool) -> error::Result<String> {
+	Ok(spec.as_json(raw)?)
 }
 
 impl<
-	TBl, TRtApi, TGen, TCSExt, TBackend,
+	TBl, TRtApi, TBackend,
 	TExecDisp, TFchr, TSc, TImpQu, TFprb, TFpp,
 	TExPool, TRpc, Backend
 > ServiceBuilderCommand for ServiceBuilder<
-	TBl, TRtApi, TGen, TCSExt,
+	TBl, TRtApi,
 	Client<TBackend, LocalCallExecutor<TBackend, NativeExecutor<TExecDisp>>, TBl, TRtApi>,
 	TFchr, TSc, TImpQu, TFprb, TFpp, TExPool, TRpc, Backend
 > where

substrate/client/service/src/config.rs

@@ -23,7 +23,7 @@ pub use sc_executor::WasmExecutionMethod;
 
 use std::{future::Future, path::{PathBuf, Path}, pin::Pin, net::SocketAddr, sync::Arc};
 pub use sc_transaction_pool::txpool::Options as TransactionPoolOptions;
-use sc_chain_spec::{ChainSpec, NoExtension};
+use sc_chain_spec::ChainSpec;
 use sp_core::crypto::Protected;
 use target_info::Target;
 use sc_telemetry::TelemetryEndpoints;
@@ -51,7 +51,7 @@ pub struct VersionInfo {
 }
 
 /// Service configuration.
-pub struct Configuration<G, E = NoExtension> {
+pub struct Configuration {
 	/// Implementation name
 	pub impl_name: &'static str,
 	/// Implementation version
@@ -79,7 +79,7 @@ pub struct Configuration<G, E = NoExtension> {
 	/// Pruning settings.
 	pub pruning: PruningMode,
 	/// Chain configuration.
-	pub chain_spec: Option<ChainSpec<G, E>>,
+	pub chain_spec: Option<Box<dyn ChainSpec>>,
 	/// Node name.
 	pub name: String,
 	/// Wasm execution method.
@@ -192,7 +192,7 @@ impl PrometheusConfig {
 	}
 }
 
-impl<G, E> Default for Configuration<G, E> {
+impl Default for Configuration {
 	/// Create a default config
 	fn default() -> Self {
 		Configuration {
@@ -233,7 +233,7 @@ impl<G, E> Default for Configuration<G, E> {
 	}
 }
 
-impl<G, E> Configuration<G, E> {
+impl Configuration {
 	/// Create a default config using `VersionInfo`
 	pub fn from_version(version: &VersionInfo) -> Self {
 		let mut config = Configuration::default();
@@ -270,8 +270,8 @@ impl<G, E> Configuration<G, E> {
 	/// ### Panics
 	///
 	/// This method panic if the `chain_spec` is `None`
-	pub fn expect_chain_spec(&self) -> &ChainSpec<G, E> {
-		self.chain_spec.as_ref().expect("chain_spec must be specified")
+	pub fn expect_chain_spec(&self) -> &dyn ChainSpec {
+		&**self.chain_spec.as_ref().expect("chain_spec must be specified")
 	}
 
 	/// Return a reference to the `DatabaseConfig` of this `Configuration`.

substrate/client/service/src/lib.rs

@@ -59,7 +59,9 @@ pub use self::builder::{
 	TFullCallExecutor, TLightCallExecutor,
 };
 pub use config::{Configuration, Roles, PruningMode};
-pub use sc_chain_spec::{ChainSpec, Properties, RuntimeGenesis, Extension as ChainSpecExtension};
+pub use sc_chain_spec::{
+	ChainSpec, GenericChainSpec, Properties, RuntimeGenesis, Extension as ChainSpecExtension
+};
 pub use sp_transaction_pool::{TransactionPool, InPoolTransaction, error::IntoPoolError};
 pub use sc_transaction_pool::txpool::Options as TransactionPoolOptions;
 pub use sc_client::FinalityNotifications;
@@ -487,8 +489,8 @@ mod waiting {
 
 /// Starts RPC servers that run in their own thread, and returns an opaque object that keeps them alive.
 #[cfg(not(target_os = "unknown"))]
-fn start_rpc_servers<G, E, H: FnMut() -> sc_rpc_server::RpcHandler<sc_rpc::Metadata>>(
-	config: &Configuration<G, E>,
+fn start_rpc_servers<H: FnMut() -> sc_rpc_server::RpcHandler<sc_rpc::Metadata>>(
+	config: &Configuration,
 	mut gen_handler: H
 ) -> Result<Box<dyn std::any::Any + Send + Sync>, error::Error> {
 	fn maybe_start_server<T, F>(address: Option<SocketAddr>, mut start: F) -> Result<Option<T>, io::Error>
@@ -528,8 +530,8 @@ fn start_rpc_servers<G, E, H: FnMut() -> sc_rpc_server::RpcHandler<sc_rpc::Metad
 
 /// Starts RPC servers that run in their own thread, and returns an opaque object that keeps them alive.
 #[cfg(target_os = "unknown")]
-fn start_rpc_servers<G, E, H: FnMut() -> sc_rpc_server::RpcHandler<sc_rpc::Metadata>>(
-	_: &Configuration<G, E>,
+fn start_rpc_servers<H: FnMut() -> sc_rpc_server::RpcHandler<sc_rpc::Metadata>>(
+	_: &Configuration,
 	_: H
 ) -> Result<Box<dyn std::any::Any + Send + Sync>, error::Error> {
 	Ok(Box::new(()))

substrate/client/service/test/src/lib.rs

@@ -29,9 +29,11 @@ use tokio::{runtime::Runtime, prelude::FutureExt};
 use tokio::timer::Interval;
 use sc_service::{
 	AbstractService,
-	ChainSpec,
+	GenericChainSpec,
+	ChainSpecExtension,
 	Configuration,
 	config::{DatabaseConfig, KeystoreConfig},
+	RuntimeGenesis,
 	Roles,
 	Error,
 };
@@ -48,7 +50,7 @@ struct TestNet<G, E, F, L, U> {
 	authority_nodes: Vec<(usize, SyncService<F>, U, Multiaddr)>,
 	full_nodes: Vec<(usize, SyncService<F>, U, Multiaddr)>,
 	light_nodes: Vec<(usize, SyncService<L>, Multiaddr)>,
-	chain_spec: ChainSpec<G, E>,
+	chain_spec: GenericChainSpec<G, E>,
 	base_port: u16,
 	nodes: usize,
 }
@@ -129,15 +131,15 @@ where F: Send + 'static, L: Send +'static, U: Clone + Send + 'static
 	}
 }
 
-fn node_config<G, E: Clone> (
+fn node_config<G: RuntimeGenesis + 'static, E: ChainSpecExtension + Clone + 'static> (
 	index: usize,
-	spec: &ChainSpec<G, E>,
+	spec: &GenericChainSpec<G, E>,
 	role: Roles,
 	task_executor: Arc<dyn Fn(Pin<Box<dyn futures::Future<Output = ()> + Send>>) + Send + Sync>,
 	key_seed: Option<String>,
 	base_port: u16,
 	root: &TempDir,
-) -> Configuration<G, E>
+) -> Configuration
 {
 	let root = root.path().join(format!("node-{}", index));
 
@@ -191,7 +193,7 @@ fn node_config<G, E: Clone> (
 		state_cache_size: 16777216,
 		state_cache_child_ratio: None,
 		pruning: Default::default(),
-		chain_spec: Some((*spec).clone()),
+		chain_spec: Some(Box::new((*spec).clone())),
 		name: format!("Node {}", index),
 		wasm_method: sc_service::config::WasmExecutionMethod::Interpreted,
 		execution_strategies: Default::default(),
@@ -217,16 +219,17 @@ fn node_config<G, E: Clone> (
 impl<G, E, F, L, U> TestNet<G, E, F, L, U> where
 	F: AbstractService,
 	L: AbstractService,
-	E: Clone,
+	E: ChainSpecExtension + Clone + 'static,
+	G: RuntimeGenesis + 'static,
 {
 	fn new(
 		temp: &TempDir,
-		spec: ChainSpec<G, E>,
-		full: impl Iterator<Item = impl FnOnce(Configuration<G, E>) -> Result<(F, U), Error>>,
-		light: impl Iterator<Item = impl FnOnce(Configuration<G, E>) -> Result<L, Error>>,
+		spec: GenericChainSpec<G, E>,
+		full: impl Iterator<Item = impl FnOnce(Configuration) -> Result<(F, U), Error>>,
+		light: impl Iterator<Item = impl FnOnce(Configuration) -> Result<L, Error>>,
 		authorities: impl Iterator<Item = (
 			String,
-			impl FnOnce(Configuration<G, E>) -> Result<(F, U), Error>
+			impl FnOnce(Configuration) -> Result<(F, U), Error>
 		)>,
 		base_port: u16
 	) -> TestNet<G, E, F, L, U> {
@@ -249,9 +252,9 @@ impl<G, E, F, L, U> TestNet<G, E, F, L, U> where
 	fn insert_nodes(
 		&mut self,
 		temp: &TempDir,
-		full: impl Iterator<Item = impl FnOnce(Configuration<G, E>) -> Result<(F, U), Error>>,
-		light: impl Iterator<Item = impl FnOnce(Configuration<G, E>) -> Result<L, Error>>,
-		authorities: impl Iterator<Item = (String, impl FnOnce(Configuration<G, E>) -> Result<(F, U), Error>)>
+		full: impl Iterator<Item = impl FnOnce(Configuration) -> Result<(F, U), Error>>,
+		light: impl Iterator<Item = impl FnOnce(Configuration) -> Result<L, Error>>,
+		authorities: impl Iterator<Item = (String, impl FnOnce(Configuration) -> Result<(F, U), Error>)>
 	) {
 		let executor = self.runtime.executor();
 
@@ -317,14 +320,15 @@ fn tempdir_with_prefix(prefix: &str) -> TempDir {
 }
 
 pub fn connectivity<G, E, Fb, F, Lb, L>(
-	spec: ChainSpec<G, E>,
+	spec: GenericChainSpec<G, E>,
 	full_builder: Fb,
 	light_builder: Lb,
 ) where
-	E: Clone,
-	Fb: Fn(Configuration<G, E>) -> Result<F, Error>,
+	E: ChainSpecExtension + Clone + 'static,
+	G: RuntimeGenesis + 'static,
+	Fb: Fn(Configuration) -> Result<F, Error>,
 	F: AbstractService,
-	Lb: Fn(Configuration<G, E>) -> Result<L, Error>,
+	Lb: Fn(Configuration) -> Result<L, Error>,
 	L: AbstractService,
 {
 	const NUM_FULL_NODES: usize = 5;
@@ -415,20 +419,21 @@ pub fn connectivity<G, E, Fb, F, Lb, L>(
 }
 
 pub fn sync<G, E, Fb, F, Lb, L, B, ExF, U>(
-	spec: ChainSpec<G, E>,
+	spec: GenericChainSpec<G, E>,
 	full_builder: Fb,
 	light_builder: Lb,
 	mut make_block_and_import: B,
 	mut extrinsic_factory: ExF
 ) where
-	Fb: Fn(Configuration<G, E>) -> Result<(F, U), Error>,
+	Fb: Fn(Configuration) -> Result<(F, U), Error>,
 	F: AbstractService,
-	Lb: Fn(Configuration<G, E>) -> Result<L, Error>,
+	Lb: Fn(Configuration) -> Result<L, Error>,
 	L: AbstractService,
 	B: FnMut(&F, &mut U),
 	ExF: FnMut(&F, &U) -> <F::Block as BlockT>::Extrinsic,
 	U: Clone + Send + 'static,
-	E: Clone,
+	E: ChainSpecExtension + Clone + 'static,
+	G: RuntimeGenesis + 'static,
 {
 	const NUM_FULL_NODES: usize = 10;
 	// FIXME: BABE light client support is currently not working.
@@ -485,16 +490,17 @@ pub fn sync<G, E, Fb, F, Lb, L, B, ExF, U>(
 }
 
 pub fn consensus<G, E, Fb, F, Lb, L>(
-	spec: ChainSpec<G, E>,
+	spec: GenericChainSpec<G, E>,
 	full_builder: Fb,
 	light_builder: Lb,
 	authorities: impl IntoIterator<Item = String>
 ) where
-	Fb: Fn(Configuration<G, E>) -> Result<F, Error>,
+	Fb: Fn(Configuration) -> Result<F, Error>,
 	F: AbstractService,
-	Lb: Fn(Configuration<G, E>) -> Result<L, Error>,
+	Lb: Fn(Configuration) -> Result<L, Error>,
 	L: AbstractService,
-	E: Clone,
+	E: ChainSpecExtension + Clone + 'static,
+	G: RuntimeGenesis + 'static,
 {
 	const NUM_FULL_NODES: usize = 10;
 	const NUM_LIGHT_NODES: usize = 10;

substrate/client/src/client.rs

@@ -243,10 +243,10 @@ impl<B, E, Block, RA> Client<B, E, Block, RA> where
 	Block: BlockT,
 {
 	/// Creates new Substrate Client with given blockchain and code executor.
-	pub fn new<S: BuildStorage>(
+	pub fn new(
 		backend: Arc<B>,
 		executor: E,
-		build_genesis_storage: &S,
+		build_genesis_storage: &dyn BuildStorage,
 		fork_blocks: ForkBlocks<Block>,
 		bad_blocks: BadBlocks<Block>,
 		execution_extensions: ExecutionExtensions<Block>,

substrate/client/src/light/mod.rs

@@ -55,9 +55,9 @@ pub fn new_light_backend<B, S>(blockchain: Arc<Blockchain<S>>) -> Arc<Backend<S,
 }
 
 /// Create an instance of light client.
-pub fn new_light<B, S, GS, RA, E>(
+pub fn new_light<B, S, RA, E>(
 	backend: Arc<Backend<S, HashFor<B>>>,
-	genesis_storage: &GS,
+	genesis_storage: &dyn BuildStorage,
 	code_executor: E,
 	prometheus_registry: Option<Registry>,
 ) -> ClientResult<
@@ -74,7 +74,6 @@ pub fn new_light<B, S, GS, RA, E>(
 	where
 		B: BlockT,
 		S: BlockchainStorage<B> + 'static,
-		GS: BuildStorage,
 		E: CodeExecutor + RuntimeInfo + Clone + 'static,
 {
 	let local_executor = LocalCallExecutor::new(backend.clone(), code_executor);

substrate/primitives/runtime/src/lib.rs

@@ -101,7 +101,7 @@ use crate::traits::IdentifyAccount;
 
 /// Complex storage builder stuff.
 #[cfg(feature = "std")]
-pub trait BuildStorage: Sized {
+pub trait BuildStorage {
 	/// Build the storage out of this builder.
 	fn build_storage(&self) -> Result<sp_core::storage::Storage, String> {
 		let mut storage = Default::default();

substrate/utils/browser/src/lib.rs

@@ -19,7 +19,7 @@ use log::{debug, info};
 use std::sync::Arc;
 use sc_service::{
 	AbstractService, RpcSession, Roles, Configuration, config::{DatabaseConfig, KeystoreConfig},
-	ChainSpec, RuntimeGenesis
+	GenericChainSpec, RuntimeGenesis
 };
 use wasm_bindgen::prelude::*;
 use futures::{prelude::*, channel::{oneshot, mpsc}, future::{poll_fn, ok}, compat::*};
@@ -34,11 +34,11 @@ pub use console_log::init_with_level as init_console_log;
 /// Create a service configuration from a chain spec.
 ///
 /// This configuration contains good defaults for a browser light client.
-pub async fn browser_configuration<G, E>(chain_spec: ChainSpec<G, E>)
-	-> Result<Configuration<G, E>, Box<dyn std::error::Error>>
+pub async fn browser_configuration<G, E>(chain_spec: GenericChainSpec<G, E>)
+	-> Result<Configuration, Box<dyn std::error::Error>>
 where
-	G: RuntimeGenesis,
-	E: Extension,
+	G: RuntimeGenesis + 'static,
+	E: Extension + 'static,
 {
 	let name = chain_spec.name().to_string();
 
@@ -46,7 +46,7 @@ where
 	let mut config = Configuration::default();
 	config.network.boot_nodes = chain_spec.boot_nodes().to_vec();
 	config.telemetry_endpoints = chain_spec.telemetry_endpoints().clone();
-	config.chain_spec = Some(chain_spec);
+	config.chain_spec = Some(Box::new(chain_spec));
 	config.network.transport = sc_network::config::TransportConfig::Normal {
 		wasm_external_transport: Some(transport.clone()),
 		allow_private_ipv4: true,

substrate/utils/frame/benchmarking-cli/src/lib.rs

@@ -14,12 +14,12 @@
 // You should have received a copy of the GNU General Public License
 // along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
 
-use std::{fmt::Debug, path::PathBuf};
-use sp_runtime::{BuildStorage, traits::{Block as BlockT, Header as HeaderT, NumberFor}};
+use std::fmt::Debug;
+use sp_runtime::{traits::{Block as BlockT, Header as HeaderT, NumberFor}};
 use sc_client::StateMachine;
 use sc_cli::{ExecutionStrategy, WasmExecutionMethod, VersionInfo};
 use sc_client_db::BenchmarkingState;
-use sc_service::{RuntimeGenesis, ChainSpecExtension, Configuration, ChainSpec};
+use sc_service::{Configuration, ChainSpec};
 use sc_executor::{NativeExecutor, NativeExecutionDispatch};
 use codec::{Encode, Decode};
 use frame_benchmarking::BenchmarkResults;
@@ -82,13 +82,11 @@ impl BenchmarkCmd {
 	}
 
 	/// Runs the command and benchmarks the chain.
-	pub fn run<G, E, BB, ExecDispatch>(
+	pub fn run<BB, ExecDispatch>(
 		self,
-		config: Configuration<G, E>,
+		config: Configuration,
 	) -> sc_cli::Result<()>
 	where
-		G: RuntimeGenesis,
-		E: ChainSpecExtension,
 		BB: BlockT + Debug,
 		<<<BB as BlockT>::Header as HeaderT>::Number as std::str::FromStr>::Err: std::fmt::Debug,
 		<BB as BlockT>::Hash: std::str::FromStr,
@@ -164,21 +162,16 @@ impl BenchmarkCmd {
 	}
 
 	/// Update and prepare a `Configuration` with command line parameters
-	pub fn update_config<G, E>(
+	pub fn update_config(
 		&self,
-		mut config: &mut Configuration<G, E>,
-		spec_factory: impl FnOnce(&str) -> Result<Option<ChainSpec<G, E>>, String>,
+		mut config: &mut Configuration,
+		spec_factory: impl FnOnce(&str) -> Result<Box<dyn ChainSpec>, String>,
 		_version: &VersionInfo,
-	) -> sc_cli::Result<()> where
-		G: RuntimeGenesis,
-		E: ChainSpecExtension,
+	) -> sc_cli::Result<()>
 	{
 		// Configure chain spec.
 		let chain_key = self.shared_params.chain.clone().unwrap_or("dev".into());
-		let spec = match spec_factory(&chain_key)? {
-			Some(spec) => spec,
-			None => ChainSpec::from_json_file(PathBuf::from(chain_key))?
-		};
+		let spec = spec_factory(&chain_key)?;
 		config.chain_spec = Some(spec);
 
 		// Make sure to configure keystore.