relayer

Relayer

Relayer service that streams transactions from blockchain networks, packages data into messages, and sends the packets to the correlated bridge component.

Thanks to Chainsafe for their work on ChainBridge. This relayer service is inspired by their design and incorporates some of their code.

• Requirements
  • Development
  • Dependencies
• Configuration
  • Secrets
• Build
• Run
• Tests

Requirements

Development

This project requires the following tools for day to day development:

• Mage: Used for build tasks
• Revive: Used for linting instead of golint

Please install them first.

Run mage to see a list of available tasks (building, testing, linting, etc).

To enable revive for linting in VS-code, add the following to your config:

{
    "go.lintTool": "revive",
    "go.lintFlags": [
        "-config=${workspaceFolder}/revive.toml"
    ],
}

Dependencies

The relayer depends on the following:

• A running parachain
• An ethereum chain with our contracts deployed

Open a new terminal, and start the parachain

cd ../parachain
target/release/artemis-node --dev

To ensure the ethereum contracts are deployed, follow the Setup guide.

Configuration

Before running the relayer, it needs to be configured first. By default the configuration file is read from ~/.config/artemis-relay/config.toml, but this can be overriden by passing the --config PATH flag to the relayer binary.

To autogenerate a valid config file, run:

scripts/make-config.sh > /tmp/relay-config.toml

# verify that the config looks like valid TOML
cat /tmp/relay-config.toml

Or, manually create a config file using the template below:

[ethereum]
endpoint = "ws://localhost:9545/"

[ethereum.bridge]
address = "0x17f7C1e314180D8b8588CA50cF09A0e0847c77F6"
abi = "/tmp/Bridge.json"

[ethereum.apps.eth]
address = "0x95aF4D3B8938063486fE23C8D8867deD6aee5646"
abi = "/tmp/ETHApp.json"

[ethereum.apps.erc20]
address = "0xb664F267fa8775563E2aD1cED44a0996198F7eE0"
abi = "/tmp/ERC20App.json"

[substrate]
endpoint = "ws://127.0.0.1:9944/"

Secrets

The relayer requires secret keys for submitting transactions to both chains. It reads these keys from environment variables.

Example:

export ARTEMIS_ETHEREUM_KEY=75fa57baca6ee656752e2daf522e75ded86d3ad24d660701aaa78e24b207f550
export ARTEMIS_SUBSTRATE_KEY=//Relay

Build

mage build

Run

Run the relayer with the config generated in Configuration.

build/artemis-relay run --config /tmp/relay-config.toml

Tests

This will run both unit and integration tests. Please ensure that both the ethereum and substrate chains are running as described in Service Dependencies.

mage test