Allow Substrate Pallet to be Halted (#485)

* Copy-Pasta owner and freezing code from `message-lane`

* Halt pallet if bridge hasn't been initialized

* Make owner optional in `message-lane` pallet

* Add `is_halted` to `InitializationData`

* Fix initialization tests

* Only allow pallet to be initialized once

* Add some logging around halting and ownership changes

* Remove `target` in debugging calls

bridges/modules/message-lane/src/lib.rs

@@ -148,7 +148,7 @@ decl_storage! {
 		/// `None`, then there are no direct ways to halt/resume pallet operations, but other
 		/// runtime methods may still be used to do that (i.e. democracy::referendum to update halt
 		/// flag directly or call the `halt_operations`).
-		pub ModuleOwner get(fn module_owner) config(): Option<T::AccountId>;
+		pub ModuleOwner get(fn module_owner): Option<T::AccountId>;
 		/// If true, all pallet transactions are failed immediately.
 		pub IsHalted get(fn is_halted) config(): bool;
 		/// Map of lane id => inbound lane data.
@@ -160,6 +160,12 @@ decl_storage! {
 	}
 	add_extra_genesis {
 		config(phantom): sp_std::marker::PhantomData<I>;
+		config(owner): Option<T::AccountId>;
+		build(|config| {
+			if let Some(ref owner) = config.owner {
+				<ModuleOwner<T, I>>::put(owner);
+			}
+		})
 	}
 }
 
@@ -188,8 +194,14 @@ decl_module! {
 		pub fn set_owner(origin, new_owner: Option<T::AccountId>) {
 			ensure_owner_or_root::<T, I>(origin)?;
 			match new_owner {
-				Some(new_owner) => ModuleOwner::<T, I>::put(new_owner),
-				None => ModuleOwner::<T, I>::kill(),
+				Some(new_owner) => {
+					ModuleOwner::<T, I>::put(&new_owner);
+					frame_support::debug::info!("Setting pallet Owner to: {:?}", new_owner);
+				},
+				None => {
+					ModuleOwner::<T, I>::kill();
+					frame_support::debug::info!("Removed Owner of pallet.");
+				},
 			}
 		}
 
@@ -200,6 +212,7 @@ decl_module! {
 		pub fn halt_operations(origin) {
 			ensure_owner_or_root::<T, I>(origin)?;
 			IsHalted::<I>::put(true);
+			frame_support::debug::warn!("Stopping pallet operations.");
 		}
 
 		/// Resume all pallet operations. May be called even if pallet is halted.
@@ -209,6 +222,7 @@ decl_module! {
 		pub fn resume_operations(origin) {
 			ensure_owner_or_root::<T, I>(origin)?;
 			IsHalted::<I>::put(false);
+			frame_support::debug::info!("Resuming pallet operations.");
 		}
 
 		/// Send message over lane.
@@ -225,7 +239,6 @@ decl_module! {
 			// let's first check if message can be delivered to target chain
 			T::TargetHeaderChain::verify_message(&payload).map_err(|err| {
 				frame_support::debug::trace!(
-					target: "runtime",
 					"Message to lane {:?} is rejected by target chain: {:?}",
 					lane_id,
 					err,
@@ -242,7 +255,6 @@ decl_module! {
 				&payload,
 			).map_err(|err| {
 				frame_support::debug::trace!(
-					target: "runtime",
 					"Message to lane {:?} is rejected by lane verifier: {:?}",
 					lane_id,
 					err,
@@ -257,7 +269,6 @@ decl_module! {
 				&delivery_and_dispatch_fee,
 			).map_err(|err| {
 				frame_support::debug::trace!(
-					target: "runtime",
 					"Message to lane {:?} is rejected because submitter {:?} is unable to pay fee {:?}: {:?}",
 					lane_id,
 					submitter,
@@ -277,7 +288,6 @@ decl_module! {
 			lane.prune_messages(T::MaxMessagesToPruneAtOnce::get());
 
 			frame_support::debug::trace!(
-				target: "runtime",
 				"Accepted message {} to lane {:?}",
 				nonce,
 				lane_id,
@@ -303,7 +313,6 @@ decl_module! {
 			let messages = verify_and_decode_messages_proof::<T::SourceHeaderChain, T::InboundMessageFee, T::InboundPayload>(proof)
 				.map_err(|err| {
 					frame_support::debug::trace!(
-						target: "runtime",
 						"Rejecting invalid messages proof: {:?}",
 						err,
 					);
@@ -323,7 +332,6 @@ decl_module! {
 				.sum();
 			if dispatch_weight < actual_dispatch_weight {
 				frame_support::debug::trace!(
-					target: "runtime",
 					"Rejecting messages proof because of dispatch weight mismatch: declared={}, expected={}",
 					dispatch_weight,
 					actual_dispatch_weight,
@@ -342,7 +350,6 @@ decl_module! {
 					let updated_latest_confirmed_nonce = lane.receive_state_update(lane_state);
 					if let Some(updated_latest_confirmed_nonce) = updated_latest_confirmed_nonce {
 						frame_support::debug::trace!(
-							target: "runtime",
 							"Received lane {:?} state update: latest_confirmed_nonce={}",
 							lane_id,
 							updated_latest_confirmed_nonce,
@@ -361,7 +368,6 @@ decl_module! {
 			}
 
 			frame_support::debug::trace!(
-				target: "runtime",
 				"Received messages: total={}, valid={}",
 				total_messages,
 				valid_messages,
@@ -378,7 +384,6 @@ decl_module! {
 			let confirmation_relayer = ensure_signed(origin)?;
 			let (lane_id, lane_data) = T::TargetHeaderChain::verify_messages_delivery_proof(proof).map_err(|err| {
 				frame_support::debug::trace!(
-					target: "runtime",
 					"Rejecting invalid messages delivery proof: {:?}",
 					err,
 				);
@@ -414,7 +419,6 @@ decl_module! {
 			}
 
 			frame_support::debug::trace!(
-				target: "runtime",
 				"Received messages delivery proof up to (and including) {} at lane {:?}",
 				lane_data.latest_received_nonce,
 				lane_id,