DAI Ethereum <-> Parity Substrate Bridge

Ethereum <-> Parity Substrate Blockchain bridge for self transfers of DAI Token (ERC20) to sDAI (ERC20 representation).

You can try it out in our chain:

1. Make sure you have Ethereum and Substrate extensions. Typical choices would be:
   a. Metamask (or any other Ethereum extension) and switch it to Kovan
   b. polkadot{.js}
2. Go here
3. Connect with both extensions(two pop-up windows should appear)
4. You will see that your balances from extensions should appear on the page.
5. Transfer some Kovan test DAI to our Substrate-based chain.
6. Transfer some DAI from our chain to your Ethereum account.

It should be pretty obvious from this point. If you hit any problems, please feel free to file an issue!

├── bridge
│   ├── ethereum
│   ├── frontend
│   └── validator - Validator service to connect Substrate to Ethereum.
├── runtime
├── scripts
├── src

Building

1. Install Rust:

curl https://sh.rustup.rs -sSf | sh

2. Install required tools:

./scripts/init.sh

3. Build the WebAssembly binary:

./scripts/build.sh

4. Build all native code:

cargo build

5. Build the validator node

Follow the validator README instructions.

6. Build frontend

Follow the frontend README instructions.

4.(Optional) Tweak configuration to use your keys and account.

Run

Start a full node:

cargo run -- --name node-name

Development

You can start a development chain with:

cargo run -- --dev

Detailed logs may be shown by running the node with the following environment variables set: RUST_LOG=debug RUST_BACKTRACE=1 cargo run -- --dev.

If you want to see the multi-node consensus algorithm in action locally, then you can create a local testnet with two validator nodes for Alice and Bob, who are the initial authorities of the genesis chain that have been endowed with testnet units. Give each node a name and expose them so they are listed on the Polkadot telemetry site. You'll need two terminal windows open.

We'll start Alice's Substrate node first on default TCP port 30333 with her chain database stored locally at /tmp/alice. The bootnode ID of her node is QmQZ8TjTqeDj3ciwr93EJ95hxfDsb9pEYDizUAbWpigtQN, which is generated from the --node-key value that we specify below:

cargo run -- \
  --base-path /tmp/alice \
  --chain=local \
  --alice \
  --node-key 0000000000000000000000000000000000000000000000000000000000000001 \
  --telemetry-url ws://telemetry.polkadot.io:1024 \
  --validator

In the second terminal, we'll start Bob's Substrate node on a different TCP port of 30334, and with his chain database stored locally at /tmp/bob. We'll specify a value for the --bootnodes option that will connect his node to Alice's bootnode ID on TCP port 30333:

cargo run -- \
  --base-path /tmp/bob \
  --bootnodes /ip4/127.0.0.1/tcp/30333/p2p/QmQZ8TjTqeDj3ciwr93EJ95hxfDsb9pEYDizUAbWpigtQN \
  --chain=local \
  --bob \
  --port 30334 \
  --telemetry-url ws://telemetry.polkadot.io:1024 \
  --validator

Additional CLI usage options are available and may be shown by running cargo run -- --help.

How it works

Make bridge on your chain

In case you want to test it in a customise-all-the-things fashion, buckle up for some extra work!

This guide will walk you through how to create an account and how to connect to AkropolisOSChain Testnet.

1. Run the node (previous steps, Build -> Run)

2. Open Akropolis UI (it’s polkadotJS app working with Substrate v.1.0). You can also use Polkadot UI.

3. Go to Settings, open Developer tab. Insert in textbox description of types (copy&paste from here) and Save it.

{
  "Count": "u64",
  "MemberId": "u64",
  "ProposalId": "u64",
  "TokenBalance": "u64",
  "TokenId": "u32",
  "Token": {
    "token_id": "u32",
    "decimals": "u16",
    "symbol": "Vec<u8>"
  },
  "Status": {
      "_enum":[
        "Pending",
        "Deposit",
        "Withdraw",
        "Approved",
        "Canceled",
        "Confirmed"
      ]
  },
    "Message": {
      "message_id": "H256",
      "eth_address": "H160",
      "substrate_address": "AccountId",
      "amount": "TokenBalance",
      "status": "Status",
      "direction": "Status"
  },
  "BridgeTransfer": {
    "transfer_id": "ProposalId",
    "message_id": "H256",
    "open": "bool",
    "votes": "MemberId"
  }
}

4. Create an account for each validator you want to launch. Go to Accounts and generate new account(and modify validators mnemonic phrase in .env file) for each validator.

5. Repeat step 4 for each validator in case you have more than one.

6. Modify validators in chain_spec.rs in GenesisConfig -> bridge

7. Repeat Build + Run instructions

8. Launch bridge/frontend(you also might need to tweak the keys and endpoints there)

9. Enjoy your local ERC20 Substrate <--> Ethereum bridge in your browser