oracle-server

Prerequisite

Install Node.js and Yarn.

• Ensure that you have a LTS Node.js installed, with version 12.x.

Build and run

To start an oracle server

1. Run yarn to install dependencies.
2. Use yarn build to build the project.
3. Use yarn start, with environment variables explained in the following section.

Environment variables

DOTENV is supported, and variables could be configured in a .ENV file.

Common

Common environment variables are needed no matter feeding for Ethereum smart contracts or Substrate based networks.

• ALPHA_VANTAGE_API_KEY: the api key of Alpha Vantage.
• PRICE_FEED_INTERVAL_MS: price feed intervals, by milliseconds.

By default, logs would be saved in error.log and combined.log. To enable logging in console, set environment variable CONSOLE_LOG as true.

Ethereum

For mainnet or Ethereum testnets like Kovan, contract addresses would be fetched from laminar-protocol/flow-protocol-ethereum package. The following environment variables would be needed:

• WEB3_PROVIDER: web3 provider.
• ETH_PRIVATE_KEY: feeder's private key.
• CHAIN: mainnet, kovan etc.
• GAS_LIMIT: gas limit.

For local testnet, additional environment variables would be needed:

• LOCAL_TESTNET_ORACLE_CONTRACT_ADDR: the oracle contract address in local testnet.
• FJPY: fJPY contract address.
• FEUR: fEUR contract address.

Substrate

• SUB_KEY_SEED: key seed.
• SUB_ENDPOINT: node endpoint, could be http/https or ws/wss.

For Laminar Chain, set FEED_LAMINAR as true; For Acala Network, set FEED_ACALA as true.

API Server

With API_KEY set, an API server would be spinned up for querying and modifying oracle server states.

The default port number would be 3000, to use a different one, set the PORT env variable.