Protocol ID configurable in the chain spec (#811)

* Protocol ID configurable in the chain spec

* Removed obsolete const

substrate/core/service/src/chain_spec.rs

@@ -76,6 +76,7 @@ struct ChainSpecFile {
 	pub id: String,
 	pub boot_nodes: Vec<String>,
 	pub telemetry_url: Option<String>,
+	pub protocol_id: Option<String>,
 }
 
 /// A configuration of a chain. Can be used to build a genesis block.
@@ -101,6 +102,10 @@ impl<G: RuntimeGenesis> ChainSpec<G> {
 		self.spec.telemetry_url.as_ref().map(String::as_str)
 	}
 
+	pub fn protocol_id(&self) -> Option<&str> {
+		self.spec.protocol_id.as_ref().map(String::as_str)
+	}
+
 	/// Parse json content into a `ChainSpec`
 	pub fn from_embedded(json: &'static [u8]) -> Result<Self, String> {
 		let spec = json::from_slice(json).map_err(|e| format!("Error parsing spec file: {}", e))?;
@@ -126,7 +131,8 @@ impl<G: RuntimeGenesis> ChainSpec<G> {
 		id: &str,
 		constructor: fn() -> G,
 		boot_nodes: Vec<String>,
-		telemetry_url: Option<&str>
+		telemetry_url: Option<&str>,
+		protocol_id: Option<&str>,
 	) -> Self
 	{
 		let spec = ChainSpecFile {
@@ -134,6 +140,7 @@ impl<G: RuntimeGenesis> ChainSpec<G> {
 			id: id.to_owned(),
 			boot_nodes: boot_nodes,
 			telemetry_url: telemetry_url.map(str::to_owned),
+			protocol_id: protocol_id.map(str::to_owned),
 		};
 		ChainSpec {
 			spec,

substrate/core/service/src/components.rs

@@ -131,9 +131,6 @@ pub trait ServiceFactory: 'static {
 	/// Other configuration for service members.
 	type Configuration: Default;
 
-	/// Network protocol id.
-	const NETWORK_PROTOCOL_ID: network::ProtocolId;
-
 	//TODO: replace these with a constructor trait. that TransactionPool implements.
 	/// Extrinsic pool constructor for the full client.
 	fn build_full_transaction_pool(config: TransactionPoolOptions, client: Arc<FullClient<Self>>)

substrate/core/service/src/lib.rs

@@ -84,6 +84,8 @@ pub use components::{ServiceFactory, FullBackend, FullExecutor, LightBackend,
 	ComponentExHash, ComponentExtrinsic,
 };
 
+const DEFAULT_PROTOCOL_ID: &'static str = "sup";
+
 /// Substrate service.
 pub struct Service<Components: components::Components> {
 	client: Arc<ComponentClient<Components>>,
@@ -171,7 +173,15 @@ impl<Components> Service<Components>
 			specialization: network_protocol,
 		};
 
-		let network = network::Service::new(network_params, Components::Factory::NETWORK_PROTOCOL_ID)?;
+		let mut protocol_id = network::ProtocolId::default();
+		let protocol_id_full = config.chain_spec.protocol_id().unwrap_or(DEFAULT_PROTOCOL_ID).as_bytes();
+		if protocol_id_full.len() > protocol_id.len() {
+			warn!("Protocol ID truncated to {} chars", protocol_id.len());
+		}
+		let id_len = protocol_id_full.len().min(protocol_id.len());
+		&mut protocol_id[0..id_len].copy_from_slice(&protocol_id_full[0..id_len]);
+
+		let network = network::Service::new(network_params, protocol_id)?;
 		on_demand.map(|on_demand| on_demand.set_service_link(Arc::downgrade(&network)));
 
 		{