Rococo & Westend People Chain (#2281)

Rococo and Westend runtimes for the "People Chain". This chain contains
the Identity pallet with plans to migrate all related data from the
Relay Chain.

Changes `IdentityInfo` to:

- Remove `additional_fields`.
- Add `github` and `discord` as first class fields. From scraping chain
data, these were the only two additional fields used (for the Fellowship
and Ambassador Program, respectively).
- Rename `riot` to `matrix`.

Note: This will use the script in
https://github.com/paritytech/polkadot-sdk/pull/2025 to generate the
genesis state.

TODO:

- [x] https://github.com/paritytech/polkadot-sdk/pull/1814 and
integration of the Identity Migrator pallet for migration.
- [x] Tests: https://github.com/paritytech/polkadot-sdk/pull/2373

---------

Co-authored-by: Muharem <ismailov.m.h@gmail.com>
Co-authored-by: Michal Kucharczyk <1728078+michalkucharczyk@users.noreply.github.com>
Co-authored-by: Dónal Murray <donal.murray@parity.io>
Co-authored-by: Richard Melkonian <35300528+0xmovses@users.noreply.github.com>
Co-authored-by: Liam Aharon <liam.aharon@hotmail.com>

cumulus/parachains/common/src/impls.rs

@@ -18,12 +18,16 @@
 
 use frame_support::traits::{
 	fungibles::{self, Balanced, Credit},
-	Contains, ContainsPair, Currency, Get, Imbalance, OnUnbalanced,
+	Contains, ContainsPair, Currency, Get, Imbalance, OnUnbalanced, OriginTrait,
 };
 use pallet_asset_tx_payment::HandleCredit;
 use sp_runtime::traits::Zero;
-use sp_std::marker::PhantomData;
-use xcm::latest::{AssetId, Fungibility::Fungible, MultiAsset, MultiLocation};
+use sp_std::{marker::PhantomData, prelude::*};
+use xcm::latest::{
+	AssetId, Fungibility, Fungibility::Fungible, Junction, Junctions::Here, MultiAsset,
+	MultiLocation, Parent, WeightLimit,
+};
+use xcm_executor::traits::ConvertLocation;
 
 /// Type alias to conveniently refer to the `Currency::NegativeImbalance` associated type.
 pub type NegativeImbalance<T> = <pallet_balances::Pallet<T> as Currency<
@@ -118,6 +122,64 @@ impl<T: Get<MultiLocation>> ContainsPair<MultiAsset, MultiLocation> for AssetsFr
 	}
 }
 
+/// Type alias to conveniently refer to the `Currency::Balance` associated type.
+pub type BalanceOf<T> =
+	<pallet_balances::Pallet<T> as Currency<<T as frame_system::Config>::AccountId>>::Balance;
+
+/// Implements `OnUnbalanced::on_unbalanced` to teleport slashed assets to relay chain treasury
+/// account.
+pub struct ToParentTreasury<TreasuryAccount, AccountIdConverter, T>(
+	PhantomData<(TreasuryAccount, AccountIdConverter, T)>,
+);
+
+impl<TreasuryAccount, AccountIdConverter, T> OnUnbalanced<NegativeImbalance<T>>
+	for ToParentTreasury<TreasuryAccount, AccountIdConverter, T>
+where
+	T: pallet_balances::Config + pallet_xcm::Config + frame_system::Config,
+	<<T as frame_system::Config>::RuntimeOrigin as OriginTrait>::AccountId: From<AccountIdOf<T>>,
+	[u8; 32]: From<<T as frame_system::Config>::AccountId>,
+	TreasuryAccount: Get<AccountIdOf<T>>,
+	AccountIdConverter: ConvertLocation<AccountIdOf<T>>,
+	BalanceOf<T>: Into<Fungibility>,
+{
+	fn on_unbalanced(amount: NegativeImbalance<T>) {
+		let amount = match amount.drop_zero() {
+			Ok(..) => return,
+			Err(amount) => amount,
+		};
+		let imbalance = amount.peek();
+		let root_location: MultiLocation = Here.into();
+		let root_account: AccountIdOf<T> =
+			match AccountIdConverter::convert_location(&root_location) {
+				Some(a) => a,
+				None => {
+					log::warn!("Failed to convert root origin into account id");
+					return
+				},
+			};
+		let treasury_account: AccountIdOf<T> = TreasuryAccount::get();
+
+		<pallet_balances::Pallet<T>>::resolve_creating(&root_account, amount);
+
+		let result = <pallet_xcm::Pallet<T>>::limited_teleport_assets(
+			<<T as frame_system::Config>::RuntimeOrigin>::root(),
+			Box::new(Parent.into()),
+			Box::new(
+				Junction::AccountId32 { network: None, id: treasury_account.into() }
+					.into_location()
+					.into(),
+			),
+			Box::new((Parent, imbalance).into()),
+			0,
+			WeightLimit::Unlimited,
+		);
+
+		if let Err(err) = result {
+			log::warn!("Failed to teleport slashed assets: {:?}", err);
+		}
+	}
+}
+
 #[cfg(test)]
 mod tests {
 	use super::*;

cumulus/parachains/common/src/polkadot.rs

@@ -20,17 +20,17 @@ pub mod account {
 	/// Polkadot treasury pallet id, used to convert into AccountId
 	pub const POLKADOT_TREASURY_PALLET_ID: PalletId = PalletId(*b"py/trsry");
 	/// Alliance pallet ID.
-	/// It is used as a temporarily place to deposit a slashed imbalance
-	/// before the teleport to the Treasury.
+	/// Used as a temporary place to deposit a slashed imbalance before teleporting to the Treasury.
 	pub const ALLIANCE_PALLET_ID: PalletId = PalletId(*b"py/allia");
 	/// Referenda pallet ID.
-	/// It is used as a temporarily place to deposit a slashed imbalance
-	/// before the teleport to the Treasury.
+	/// Used as a temporary place to deposit a slashed imbalance before teleporting to the Treasury.
 	pub const REFERENDA_PALLET_ID: PalletId = PalletId(*b"py/refer");
 	/// Ambassador Referenda pallet ID.
-	/// It is used as a temporarily place to deposit a slashed imbalance
-	/// before the teleport to the Treasury.
+	/// Used as a temporary place to deposit a slashed imbalance before teleporting to the Treasury.
 	pub const AMBASSADOR_REFERENDA_PALLET_ID: PalletId = PalletId(*b"py/amref");
+	/// Identity pallet ID.
+	/// Used as a temporary place to deposit a slashed imbalance before teleporting to the Treasury.
+	pub const IDENTITY_PALLET_ID: PalletId = PalletId(*b"py/ident");
 	/// Fellowship treasury pallet ID
 	pub const FELLOWSHIP_TREASURY_PALLET_ID: PalletId = PalletId(*b"py/feltr");
 }