aalu1418 / cfx-eth-chainlink-bridge

Demo project to send transactions between Conflux Network and Ethereum (Testnets: Oceanus + Ropsten)

CFX <=> ETH Chainlink Bridge

Simple project send transactions to/from Conflux Network to/from Ethereum - deployed on the Conflux Oceanus mainnet and the Ropsten testnet.

At a conceptual level, oracles connect blockchains to off-chain information, and bridges connect one blockchain to another. The other blockchain is considered "off-chain" to the original blockchain, hence a direct parallel to oracles.

Components

• Chainlink Node
• External Initiator
• External Adapter for ETH & CFX
• Conflux Network Endpoint
• Ethereum Network Endpoint
• PostgreSQL Database (x2)
• On-Chain Smart Contracts

Technical Details

Starting a Chainlink node

Follow the instructions here: : https://docs.chain.link/docs/running-a-chainlink-node

.env file for starting the Chainlink node (added: FEATURE_EXTERNAL_INITIATORS=true)

ROOT=/chainlink
LOG_LEVEL=debug
ETH_CHAIN_ID=3
MIN_OUTGOING_CONFIRMATIONS=2
LINK_CONTRACT_ADDRESS=0x20fe562d797a42dcb3399062ae9546cd06f63280
CHAINLINK_TLS_PORT=0
SECURE_COOKIES=false
ALLOW_ORIGINS=*
DATABASE_TIMEOUT=0
DATABASE_URL=DATABASE_URL=postgresql://$USERNAME:$PASSWORD@$SERVER:$PORT/$DATABASE
FEATURE_EXTERNAL_INITIATORS=true
ETH_URL=CHANGEME

Start up command without password files:

cd ~/.chainlink-ropsten && docker run -p 6688:6688 -v ~/.chainlink-ropsten:/chainlink -it --env-file=.env smartcontract/chainlink local n -p /chainlink/.password -a /chainlink/.api

Star up command with password files:
Setup details

cd ~/.chainlink-ropsten && docker run -p 6688:6688 -v ~/.chainlink-ropsten:/chainlink -it --env-file=.env smartcontract/chainlink local n -p /chainlink/.password -a /chainlink/.api

Setting up external initiator

Connecting the external initiator (EI) to Chainlink node.

Get the container ID using docker ps

docker exec -it <containerID> /bin/bash
chainlink admin login
chainlink initiator create cfx http://172.17.0.1:8080/jobs

Add the generated access tokens ./external-initiator/.env

EI_DATABASEURL=postgresql://$USERNAME:$PASSWORD@$SERVER:$PORT/$DATABASE
EI_CHAINLINKURL=http://localhost:6688
EI_IC_ACCESSKEY=<INSERT KEY>
EI_IC_SECRET=<INSERT KEY>
EI_CI_ACCESSKEY=<INSERT KEY>
EI_CI_SECRET=<INSERT KEY>

Initial startup:

./external-initiator "{\"name\":\"cfx-mainnet\",\"type\":\"conflux\",\"url\":\"http://mainnet-jsonrpc.conflux-chain.org:12537\"}" --chainlinkurl "http://localhost:6688/"

Normal startup command:

./external-initiator

Setting up the external adapter

Login to the Chainlink node and add two bridges:

Adapter	URL
cfxTx	http://172.17.0.1:3000/cfx
ethTxCustom	http://172.17.0.1:3000/eth

The external adapter can be started with yarn start-adapter.

Job Specs

CFX Transaction => External Initiator => Chainlink Node => External Adapter => ETH Transaction
See: CFX job spec

ETH Transaction => Chainlink Node => External Adapter => CFX Transaction
See: ETH job spec

Notes

• CL node only sends 32 bytes of data in ethtx adapter, so customEthTx is used for sending longer data