Files
pezkuwi-subxt/cumulus/parachains/runtimes/bridge-hubs
Francisco Aguirre 8428f678fe XCMv4 (#1230)
# Note for reviewer

Most changes are just syntax changes necessary for the new version.
Most important files should be the ones under the `xcm` folder.

# Description 

Added XCMv4.

## Removed `Multi` prefix
The following types have been renamed:
- MultiLocation -> Location
- MultiAsset -> Asset
- MultiAssets -> Assets
- InteriorMultiLocation -> InteriorLocation
- MultiAssetFilter -> AssetFilter
- VersionedMultiAsset -> VersionedAsset
- WildMultiAsset -> WildAsset
- VersionedMultiLocation -> VersionedLocation

In order to fix a name conflict, the `Assets` in `xcm-executor` were
renamed to `HoldingAssets`, as they represent assets in holding.

## Removed `Abstract` asset id

It was not being used anywhere and this simplifies the code.

Now assets are just constructed as follows:

```rust
let asset: Asset = (AssetId(Location::new(1, Here)), 100u128).into();
```

No need for specifying `Concrete` anymore.

## Outcome is now a named fields struct

Instead of

```rust
pub enum Outcome {
  Complete(Weight),
  Incomplete(Weight, Error),
  Error(Error),
}
```

we now have

```rust
pub enum Outcome {
  Complete { used: Weight },
  Incomplete { used: Weight, error: Error },
  Error { error: Error },
}
```

## Added Reanchorable trait

Now both locations and assets implement this trait, making it easier to
reanchor both.

## New syntax for building locations and junctions

Now junctions are built using the following methods:

```rust
let location = Location {
    parents: 1,
    interior: [Parachain(1000), PalletInstance(50), GeneralIndex(1984)].into()
};
```

or

```rust
let location = Location::new(1, [Parachain(1000), PalletInstance(50), GeneralIndex(1984)]);
```

And they are matched like so:

```rust
match location.unpack() {
  (1, [Parachain(id)]) => ...
  (0, Here) => ...,
  (1, [_]) => ...,
}
```

This syntax is mandatory in v4, and has been also implemented for v2 and
v3 for easier migration.

This was needed to make all sizes smaller.

# TODO
- [x] Scaffold v4
- [x] Port github.com/paritytech/polkadot/pull/7236
- [x] Remove `Multi` prefix
- [x] Remove `Abstract` asset id

---------

Co-authored-by: command-bot <>
Co-authored-by: Keith Yeung <kungfukeith11@gmail.com>
2024-01-16 18:18:04 +00:00
..
2024-01-16 18:18:04 +00:00
2024-01-16 18:18:04 +00:00
2024-01-16 18:18:04 +00:00
2024-01-16 18:18:04 +00:00

Bridge-hub Parachains

BridgeHub(s) are system parachains that will house trustless bridges from the local ecosystem to others. The current trustless bridges planned for the BridgeHub(s) are:

  • BridgeHubPolkadot system parachain:
    1. Polkadot <-> Kusama bridge
    2. Polkadot <-> Ethereum bridge (Snowbridge)
  • BridgeHubKusama system parachain:
    1. Kusama <-> Polkadot bridge
    2. Kusama <-> Ethereum bridge The high-level responsibilities of each bridge living on BridgeHub:
  • sync finality proofs between relay chains (or equivalent)
  • sync finality proofs between BridgeHub parachains
  • pass (XCM) messages between different BridgeHub parachains

Requirements for local run/testing

# Prepare empty directory for testing
mkdir -p ~/local_bridge_testing/bin
mkdir -p ~/local_bridge_testing/logs

---
# 1. Install zombienet
Go to: https://github.com/paritytech/zombienet/releases
Copy the apropriate binary (zombienet-linux) from the latest release to ~/local_bridge_testing/bin


---
# 2. Build polkadot binary

We need polkadot binary with "fast-runtime" feature:

cd <polkadot-sdk-git-repo-dir>
cargo build --release --features fast-runtime --bin polkadot
cp target/release/polkadot ~/local_bridge_testing/bin/polkadot

cargo build --release --features fast-runtime --bin polkadot-prepare-worker
cp target/release/polkadot-prepare-worker ~/local_bridge_testing/bin/polkadot-prepare-worker

cargo build --release --features fast-runtime --bin polkadot-execute-worker
cp target/release/polkadot-execute-worker ~/local_bridge_testing/bin/polkadot-execute-worker


---
# 3. Build substrate-relay binary
git clone https://github.com/paritytech/parity-bridges-common.git
cd parity-bridges-common

# checkout desired branch or use master:
# git checkout -b master --track origin/master
# `polkadot-staging` (recommended) is stabilized and compatible for Cumulus releases
# `master` is latest development
git checkout -b polkadot-staging --track origin/polkadot-staging

cargo build --release -p substrate-relay
cp target/release/substrate-relay ~/local_bridge_testing/bin/substrate-relay


---
# 4. Build cumulus polkadot-parachain binary
cd <polkadot-sdk-git-repo-dir>

cargo build --release -p polkadot-parachain-bin
cp target/release/polkadot-parachain ~/local_bridge_testing/bin/polkadot-parachain
cp target/release/polkadot-parachain ~/local_bridge_testing/bin/polkadot-parachain-asset-hub

How to test local Rococo <-> Westend bridge

Run Rococo/Westend chains with zombienet

cd <polkadot-sdk-git-repo-dir>

# Rococo + BridgeHubRococo + AssetHub for Rococo (mirroring Kusama)
POLKADOT_BINARY_PATH=~/local_bridge_testing/bin/polkadot \
POLKADOT_PARACHAIN_BINARY_PATH=~/local_bridge_testing/bin/polkadot-parachain \
POLKADOT_PARACHAIN_BINARY_PATH_FOR_ASSET_HUB_ROCOCO=~/local_bridge_testing/bin/polkadot-parachain-asset-hub \
	~/local_bridge_testing/bin/zombienet-linux --provider native spawn ./cumulus/zombienet/bridge-hubs/bridge_hub_rococo_local_network.toml
cd <polkadot-sdk-git-repo-dir>

# Westend + BridgeHubWestend + AssetHub for Westend (mirroring Polkadot)
POLKADOT_BINARY_PATH=~/local_bridge_testing/bin/polkadot \
POLKADOT_PARACHAIN_BINARY_PATH=~/local_bridge_testing/bin/polkadot-parachain \
POLKADOT_PARACHAIN_BINARY_PATH_FOR_ASSET_HUB_WESTEND=~/local_bridge_testing/bin/polkadot-parachain-asset-hub \
	~/local_bridge_testing/bin/zombienet-linux --provider native spawn ./cumulus/zombienet/bridge-hubs/bridge_hub_westend_local_network.toml

Init bridge and run relayer between BridgeHubRococo and BridgeHubWestend

Accounts of BridgeHub parachains:

  • Bob is pallet owner of all bridge pallets

Run with script

cd <polkadot-sdk-git-repo-dir>

./cumulus/scripts/bridges_rococo_westend.sh run-relay

Check relay-chain headers relaying:

Check parachain headers relaying:

Initialize configuration for transfer asset over bridge (ROCs/WNDs)

This initialization does several things:

  • creates ForeignAssets for wrappedROCs/wrappedWNDs
  • drips SA for AssetHubRococo on AssetHubWestend (and vice versa) which holds reserved assets on source chains
cd <polkadot-sdk-git-repo-dir>

./cumulus/scripts/bridges_rococo_westend.sh init-asset-hub-rococo-local
./cumulus/scripts/bridges_rococo_westend.sh init-bridge-hub-rococo-local
./cumulus/scripts/bridges_rococo_westend.sh init-asset-hub-westend-local
./cumulus/scripts/bridges_rococo_westend.sh init-bridge-hub-westend-local

Send messages - transfer asset over bridge (ROCs/WNDs)

Do reserve-backed transfers:

cd <polkadot-sdk-git-repo-dir>

# ROCs from Rococo's Asset Hub to Westend's.
./cumulus/scripts/bridges_rococo_westend.sh reserve-transfer-assets-from-asset-hub-rococo-local
cd <polkadot-sdk-git-repo-dir>

# WNDs from Westend's Asset Hub to Rococo's.
./cumulus/scripts/bridges_rococo_westend.sh reserve-transfer-assets-from-asset-hub-westend-local

Do reserve withdraw transfers: (when previous is finished)

cd <polkadot-sdk-git-repo-dir>

# wrappedWNDs from Rococo's Asset Hub to Westend's.
./cumulus/scripts/bridges_rococo_westend.sh withdraw-reserve-assets-from-asset-hub-rococo-local
cd <polkadot-sdk-git-repo-dir>

# wrappedROCs from Westend's Asset Hub to Rococo's.
./cumulus/scripts/bridges_rococo_westend.sh withdraw-reserve-assets-from-asset-hub-westend-local

Claim relayer's rewards on BridgeHubRococo and BridgeHubWestend

Accounts of BridgeHub parachains:

  • //Charlie is relayer account on BridgeHubRococo
  • //Charlie is relayer account on BridgeHubWestend
cd <polkadot-sdk-git-repo-dir>

# Claim rewards on BridgeHubWestend:
./cumulus/scripts/bridges_rococo_westend.sh claim-rewards-bridge-hub-rococo-local

# Claim rewards on BridgeHubWestend:
./cumulus/scripts/bridges_rococo_westend.sh claim-rewards-bridge-hub-westend-local

How to test local BridgeHubKusama/BridgeHubPolkadot

TODO: see # !!! READ HERE above