[AHM] Schedule migration on runtime upgrade (#934)

Schedule the AHM on runtime upgrade so we can avoid doing another
fellowship call.
Exact values will be set in the subsequent runtime release MR.

Changes:
- Factor scheduling logic out into `do_schedule_migration`
- Add `KickoffAhm` to Kusama RC runtime
- Put a placeholder for the actual scheduling values that we can fill in
later

---------

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>

Author: ggwpez

pallets/rc-migrator/src/lib.rs

@@ -965,26 +965,13 @@ pub mod pallet {
 		) -> DispatchResultWithPostInfo {
 			Self::ensure_admin_or_manager(origin)?;
 
-			let now = frame_system::Pallet::<T>::block_number();
-			let start = start.evaluate(now);
-
-			ensure!(start > now, Error::<T>::PastBlockNumber);
-
-			if !unsafe_ignore_staking_lock_check {
-				let until_start = start.saturating_sub(now);
-				let two_session_duration: u32 = <T as Config>::SessionDuration::get()
-					.saturating_mul(2)
-					.try_into()
-					.map_err(|_| Error::<T>::EraEndsTooSoon)?;
+			Self::do_schedule_migration(
+				start,
+				warm_up,
+				cool_off,
+				unsafe_ignore_staking_lock_check,
+			)?;
 
-				// We check > and not >= here since the on_initialize for this block already ran.
-				ensure!(until_start > two_session_duration.into(), Error::<T>::EraEndsTooSoon);
-			}
-
-			WarmUpPeriod::<T>::put(warm_up);
-			CoolOffPeriod::<T>::put(cool_off);
-
-			Self::transition(MigrationStage::Scheduled { start });
 			Ok(Pays::No.into())
 		}
 
@@ -2392,6 +2379,34 @@ pub mod pallet {
 	}
 
 	impl<T: Config> Pallet<T> {
+		pub fn do_schedule_migration(
+			start: DispatchTime<BlockNumberFor<T>>,
+			warm_up: DispatchTime<BlockNumberFor<T>>,
+			cool_off: DispatchTime<BlockNumberFor<T>>,
+			unsafe_ignore_staking_lock_check: bool,
+		) -> DispatchResult {
+			let now = frame_system::Pallet::<T>::block_number();
+			let start = start.evaluate(now);
+
+			ensure!(start > now, Error::<T>::PastBlockNumber);
+
+			if !unsafe_ignore_staking_lock_check {
+				let until_start = start.saturating_sub(now);
+				let two_session_duration: u32 = <T as Config>::SessionDuration::get()
+					.saturating_mul(2)
+					.try_into()
+					.map_err(|_| Error::<T>::EraEndsTooSoon)?;
+
+				// We check > and not >= here since the on_initialize for this block already ran.
+				ensure!(until_start > two_session_duration.into(), Error::<T>::EraEndsTooSoon);
+			}
+
+			WarmUpPeriod::<T>::put(warm_up);
+			CoolOffPeriod::<T>::put(cool_off);
+
+			Self::transition(MigrationStage::Scheduled { start });
+			Ok(())
+		}
 		/// Ensure that the origin is [`Config::AdminOrigin`] or signed by [`Manager`] account id.
 		fn ensure_admin_or_manager(origin: OriginFor<T>) -> DispatchResult {
 			if let Ok(account_id) = ensure_signed(origin.clone()) {

relay/kusama/src/lib.rs

@@ -2190,12 +2190,43 @@ pub type Migrations = (migrations::Unreleased, migrations::Permanent);
 #[allow(deprecated, missing_docs)]
 pub mod migrations {
 	use super::*;
+	use frame_support::traits::OnRuntimeUpgrade;
+	use pallet_rc_migrator::{MigrationStage, MigrationStartBlock, RcMigrationStage};
 
 	/// Unreleased migrations. Add new ones here:
-	pub type Unreleased = ();
+	pub type Unreleased = (KickOffAhm<Runtime>,);
 
 	/// Migrations/checks that do not need to be versioned and can run on every update.
 	pub type Permanent = pallet_xcm::migration::MigrateToLatestXcmVersion<Runtime>;
+
+	/// Kick off the Asset Hub Migration.
+	pub struct KickOffAhm<T>(pub core::marker::PhantomData<T>);
+	impl<T: pallet_rc_migrator::Config> OnRuntimeUpgrade for KickOffAhm<T> {
+		fn on_runtime_upgrade() -> Weight {
+			if MigrationStartBlock::<T>::exists() ||
+				RcMigrationStage::<T>::get() != MigrationStage::Pending
+			{
+				// Already started or scheduled
+				log::info!("KickOffAhm: Asset Hub Migration already started or scheduled");
+				return T::DbWeight::get().reads(2)
+			}
+
+			// We will set this as part of the release MR
+			/*let result = pallet_rc_migrator::Pallet::<T>::do_schedule_migration(
+				DispatchTime::After(/* START */),
+				DispatchTime::After(/* WARM UP */),
+				DispatchTime::After(/* COOL OFF */),
+				Default::default(),
+			);
+			if let Err(e) = result {
+				log::error!("KickOffAhm: Failed to schedule Asset Hub Migration: {:?}", e);
+			} else {
+				log::info!("KickOffAhm: Scheduled Asset Hub Migration");
+			}*/
+
+			T::DbWeight::get().reads_writes(1, 1)
+		}
+	}
 }
 
 /// Unchecked extrinsic type as expected by this runtime.