CLI improvements & fixes (#4812)

These are a few changes I missed during the refactoring.

1. Initialization issue and boilerplate

    Most importantly: part of the `Configuration` initialization was done in `sc_cli::init`. This means the user can not benefit from this initialization boilerplate if they have multiple `Configuration` since `sc_cli::init` can only be called once.

2. Boilerplate for `VersionInfo` and `Configuration`

    I'm also answering to the critic of @bkchr on the initialization using version: https://github.com/paritytech/substrate/pull/4692/files/bea809d4c14a2ede953227ac885e3b3f9771c548#r372047238 This will allow initializing a `Configuration` and provide the version by default.

3. Loading the `chain_spec` explicitly

    In the past it was done automatically but in some cases we want to delay this. I moved the code to `Configuration.load_spec()` so it can be called later on. `chain_spec` can also be written directly to the `Configuration` without using this `load_spec` helper.

4. [deleted]

5. Fixing issue that prevents the user to override the port

    In the refactoring I introduced a bug by mistake that could potentially prevent the CLI user to override the ports if defaults where provided for these ports (only on cumulus).

6. Change task_executor from Box to Arc

    This is useful for cumulus where we have 2 nodes with 2 separate Configuration that need to spawn tasks to the same runtime.

7. Renamed TasksExecutorRequired to TaskExecutor

    For consistency.

This is related to https://github.com/paritytech/cumulus/issues/24

This is the continuation (and hopefully the end of) #4692

substrate/client/service/src/builder.rs

@@ -196,7 +196,7 @@ fn new_full_parts<TBl, TRtApi, TExecDisp, TGen, TCSExt>(
 			state_cache_child_ratio:
 			config.state_cache_child_ratio.map(|v| (v, 100)),
 			pruning: config.pruning.clone(),
-			source: match &config.database {
+			source: match config.expect_database() {
 				DatabaseConfig::Path { path, cache_size } =>
 					sc_client_db::DatabaseSettingsSrc::Path {
 						path: path.clone(),
@@ -307,7 +307,7 @@ where TGen: RuntimeGenesis, TCSExt: Extension {
 				state_cache_child_ratio:
 					config.state_cache_child_ratio.map(|v| (v, 100)),
 				pruning: config.pruning.clone(),
-				source: match &config.database {
+				source: match config.expect_database() {
 					DatabaseConfig::Path { path, cache_size } =>
 						sc_client_db::DatabaseSettingsSrc::Path {
 							path: path.clone(),
@@ -1187,7 +1187,7 @@ ServiceBuilder<
 			task_executor: if let Some(exec) = config.task_executor {
 				exec
 			} else {
-				return Err(Error::TasksExecutorRequired);
+				return Err(Error::TaskExecutorRequired);
 			},
 			rpc_handlers,
 			_rpc: rpc,

substrate/client/service/src/config.rs

@@ -28,6 +28,27 @@ use sp_core::crypto::Protected;
 use target_info::Target;
 use sc_telemetry::TelemetryEndpoints;
 
+/// Executable version. Used to pass version information from the root crate.
+#[derive(Clone)]
+pub struct VersionInfo {
+	/// Implementation name.
+	pub name: &'static str,
+	/// Implementation version.
+	pub version: &'static str,
+	/// SCM Commit hash.
+	pub commit: &'static str,
+	/// Executable file name.
+	pub executable_name: &'static str,
+	/// Executable file description.
+	pub description: &'static str,
+	/// Executable file author.
+	pub author: &'static str,
+	/// Support URL.
+	pub support_url: &'static str,
+	/// Copyright starting year (x-current year)
+	pub copyright_start_year: i32,
+}
+
 /// Service configuration.
 pub struct Configuration<G, E = NoExtension> {
 	/// Implementation name
@@ -39,7 +60,7 @@ pub struct Configuration<G, E = NoExtension> {
 	/// Node roles.
 	pub roles: Roles,
 	/// How to spawn background tasks. Mandatory, otherwise creating a `Service` will error.
-	pub task_executor: Option<Box<dyn Fn(Pin<Box<dyn Future<Output = ()> + Send>>) + Send>>,
+	pub task_executor: Option<Arc<dyn Fn(Pin<Box<dyn Future<Output = ()> + Send>>) + Send + Sync>>,
 	/// Extrinsic pool configuration.
 	pub transaction_pool: TransactionPoolOptions,
 	/// Network configuration.
@@ -49,7 +70,7 @@ pub struct Configuration<G, E = NoExtension> {
 	/// Configuration for the keystore.
 	pub keystore: KeystoreConfig,
 	/// Configuration for the database.
-	pub database: DatabaseConfig,
+	pub database: Option<DatabaseConfig>,
 	/// Size of internal state cache in Bytes
 	pub state_cache_size: usize,
 	/// Size in percent of cache size dedicated to child tries
@@ -147,7 +168,7 @@ pub enum DatabaseConfig {
 impl<G, E> Default for Configuration<G, E> {
 	/// Create a default config
 	fn default() -> Self {
-		let configuration = Configuration {
+		Configuration {
 			impl_name: "parity-substrate",
 			impl_version: "0.0.0",
 			impl_commit: "",
@@ -159,10 +180,7 @@ impl<G, E> Default for Configuration<G, E> {
 			transaction_pool: Default::default(),
 			network: Default::default(),
 			keystore: KeystoreConfig::None,
-			database: DatabaseConfig::Path {
-				path: Default::default(),
-				cache_size: Default::default(),
-			},
+			database: None,
 			state_cache_size: Default::default(),
 			state_cache_child_ratio: Default::default(),
 			pruning: PruningMode::default(),
@@ -183,14 +201,21 @@ impl<G, E> Default for Configuration<G, E> {
 			dev_key_seed: None,
 			tracing_targets: Default::default(),
 			tracing_receiver: Default::default(),
-		};
-
-		configuration
+		}
 	}
-
 }
 
 impl<G, E> Configuration<G, E> {
+	/// Create a default config using `VersionInfo`
+	pub fn new(version: &VersionInfo) -> Self {
+		let mut config = Configuration::default();
+		config.impl_name = version.name;
+		config.impl_version = version.version;
+		config.impl_commit = version.commit;
+
+		config
+	}
+
 	/// Returns full version string of this configuration.
 	pub fn full_version(&self) -> String {
 		full_version_from_strs(self.impl_version, self.impl_commit)
@@ -220,6 +245,15 @@ impl<G, E> Configuration<G, E> {
 	pub fn expect_chain_spec(&self) -> &ChainSpec<G, E> {
 		self.chain_spec.as_ref().expect("chain_spec must be specified")
 	}
+
+	/// Return a reference to the `DatabaseConfig` of this `Configuration`.
+	///
+	/// ### Panics
+	///
+	/// This method panic if the `database` is `None`
+	pub fn expect_database(&self) -> &DatabaseConfig {
+		self.database.as_ref().expect("database must be specified")
+	}
 }
 
 /// Returns platform info

substrate/client/service/src/error.rs

@@ -42,7 +42,7 @@ pub enum Error {
 	SelectChainRequired,
 	/// Tasks executor is missing.
 	#[display(fmt="Tasks executor hasn't been provided.")]
-	TasksExecutorRequired,
+	TaskExecutorRequired,
 	/// Other error.
 	Other(String),
 }

substrate/client/service/src/lib.rs

@@ -96,7 +96,7 @@ pub struct Service<TBl, TCl, TSc, TNetStatus, TNet, TTxPool, TOc> {
 	/// Receiver for futures that must be spawned as background tasks.
 	to_spawn_rx: mpsc::UnboundedReceiver<(Pin<Box<dyn Future<Output = ()> + Send>>, Cow<'static, str>)>,
 	/// How to spawn background tasks.
-	task_executor: Box<dyn Fn(Pin<Box<dyn Future<Output = ()> + Send>>) + Send>,
+	task_executor: Arc<dyn Fn(Pin<Box<dyn Future<Output = ()> + Send>>) + Send + Sync>,
 	rpc_handlers: sc_rpc_server::RpcHandler<sc_rpc::Metadata>,
 	_rpc: Box<dyn std::any::Any + Send + Sync>,
 	_telemetry: Option<sc_telemetry::Telemetry>,