Adds deregister_validators call for propose-parachain (#2615)

Author: bkchr

runtime/rococo/src/lib.rs

@@ -103,7 +103,7 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
 	spec_name: create_runtime_str!("rococo"),
 	impl_name: create_runtime_str!("parity-rococo-v1-1"),
 	authoring_version: 0,
-	spec_version: 210,
+	spec_version: 215,
 	impl_version: 0,
 	#[cfg(not(feature = "disable-runtime-api"))]
 	apis: RUNTIME_API_VERSIONS,

runtime/rococo/src/propose_parachain.rs

@@ -107,6 +107,8 @@ decl_event! {
 		ParachainRegistered(ParaId),
 		/// New validators were added to the set.
 		ValidatorsRegistered(Vec<ValidatorId>),
+		/// Validators were removed from the set.
+		ValidatorsDeregistered(Vec<ValidatorId>),
 	}
 }
 
@@ -296,6 +298,8 @@ decl_module! {
 		}
 
 		/// Add new validators to the set.
+		///
+		/// The new validators will be active from current session + 2.
 		#[weight = 100_000]
 		fn register_validators(
 			origin,
@@ -307,6 +311,21 @@ decl_module! {
 
 			Self::deposit_event(RawEvent::ValidatorsRegistered(validators));
 		}
+
+		/// Remove validators from the set.
+		///
+		/// The removed validators will be deactivated from current session + 2.
+		#[weight = 100_000]
+		fn deregister_validators(
+			origin,
+			validators: Vec<T::ValidatorId>,
+		) {
+			T::PriviledgedOrigin::ensure_origin(origin)?;
+
+			validators.clone().into_iter().for_each(|v| ValidatorsToRetire::<T>::append(v));
+
+			Self::deposit_event(RawEvent::ValidatorsDeregistered(validators));
+		}
 	}
 }