Add new RPC method to get the chain type (#5576)

* Add new RPC method to get the chain type

This adds a new RPC method to get the chain type of the running chain.
The chain type needs to be specified in the chain spec. This should make
it easier for tools/UI to display extra information without needing to
rely on parsing the chain name.

* Update client/rpc-api/src/system/mod.rs

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

* Primitive crate

* Feedback

Co-authored-by: Tomasz Drwięga <tomusdrw@users.noreply.github.com>

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

@@ -25,8 +25,7 @@ use serde::{Serialize, Deserialize};
 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 crate::{RuntimeGenesis, ChainType, extension::GetExtension, Properties};
 use sc_network::config::MultiaddrWithPeerId;
 use sc_telemetry::TelemetryEndpoints;
 
@@ -137,6 +136,8 @@ enum Genesis<G> {
 struct ClientSpec<E> {
 	name: String,
 	id: String,
+	#[serde(default)]
+	chain_type: ChainType,
 	boot_nodes: Vec<MultiaddrWithPeerId>,
 	telemetry_endpoints: Option<TelemetryEndpoints>,
 	protocol_id: Option<String>,
@@ -149,9 +150,6 @@ struct ClientSpec<E> {
 	genesis: serde::de::IgnoredAny,
 }
 
-/// Arbitrary properties defined in chain spec as a JSON object
-pub type Properties = json::map::Map<String, json::Value>;
-
 /// A type denoting empty extensions.
 ///
 /// We use `Option` here since `()` is not flattenable by serde.
@@ -219,6 +217,7 @@ impl<G, E> ChainSpec<G, E> {
 	pub fn from_genesis<F: Fn() -> G + 'static + Send + Sync>(
 		name: &str,
 		id: &str,
+		chain_type: ChainType,
 		constructor: F,
 		boot_nodes: Vec<MultiaddrWithPeerId>,
 		telemetry_endpoints: Option<TelemetryEndpoints>,
@@ -229,6 +228,7 @@ impl<G, E> ChainSpec<G, E> {
 		let client_spec = ClientSpec {
 			name: name.to_owned(),
 			id: id.to_owned(),
+			chain_type,
 			boot_nodes,
 			telemetry_endpoints,
 			protocol_id: protocol_id.map(str::to_owned),
@@ -243,6 +243,11 @@ impl<G, E> ChainSpec<G, E> {
 			genesis: GenesisSource::Factory(Arc::new(constructor)),
 		}
 	}
+
+	/// Type of the chain.
+	fn chain_type(&self) -> ChainType {
+		self.client_spec.chain_type.clone()
+	}
 }
 
 impl<G, E: serde::de::DeserializeOwned> ChainSpec<G, E> {
@@ -332,6 +337,10 @@ where
 		ChainSpec::id(self)
 	}
 
+	fn chain_type(&self) -> ChainType {
+		ChainSpec::chain_type(self)
+	}
+
 	fn telemetry_endpoints(&self) -> &Option<TelemetryEndpoints> {
 		ChainSpec::telemetry_endpoints(self)
 	}
@@ -392,6 +401,7 @@ mod tests {
 		).unwrap();
 
 		assert_eq!(spec1.as_json(false), spec2.as_json(false));
+		assert_eq!(spec2.chain_type(), ChainType::Live)
 	}
 
 	#[derive(Debug, Serialize, Deserialize)]

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

@@ -107,13 +107,13 @@
 //! pub type MyChainSpec<G> = GenericChainSpec<G, Extension>;
 //! ```
 
-
 mod chain_spec;
 mod extension;
 
-pub use chain_spec::{ChainSpec as GenericChainSpec, Properties, NoExtension};
+pub use chain_spec::{ChainSpec as GenericChainSpec, NoExtension};
 pub use extension::{Group, Fork, Forks, Extension, GetExtension, get_extension};
 pub use sc_chain_spec_derive::{ChainSpecExtension, ChainSpecGroup};
+pub use sp_chain_spec::{Properties, ChainType};
 
 use serde::{Serialize, de::DeserializeOwned};
 use sp_runtime::BuildStorage;
@@ -124,12 +124,14 @@ use sc_telemetry::TelemetryEndpoints;
 pub trait RuntimeGenesis: Serialize + DeserializeOwned + BuildStorage {}
 impl<T: Serialize + DeserializeOwned + BuildStorage> RuntimeGenesis for T {}
 
-/// Common interface to `GenericChainSpec`
+/// Common interface of a chain specification.
 pub trait ChainSpec: BuildStorage + Send {
 	/// Spec name.
 	fn name(&self) -> &str;
 	/// Spec id.
 	fn id(&self) -> &str;
+	/// Type of the chain.
+	fn chain_type(&self) -> ChainType;
 	/// A list of bootnode addresses.
 	fn boot_nodes(&self) -> &[MultiaddrWithPeerId];
 	/// Telemetry endpoints (if any)