This is the job app that feed contract (price feeder) with price BTC-USD | RIF-USD | ETH-BTC | USDT-USD
Reference price (BTCUSD) for MoC system is provided via an oracle (the medianizer), which collates price data from a number of external price feeds. Take a look to:
-
Proxy Oracle: If you don't want to change oracle address when we change to new generation of oracle (decentralized oracle)
Price Feeds
Independent price feed operators constantly monitor the reference price across a number of external sources and will submit updates to the blockchain.
Price updates are written to the blockchain via price feed contracts which are deployed and owned by feed operators. Price feed contracts which have been whitelisted by the medianizer are able to forward their prices for inclusion in the medianized price.
The Medianizer
The medianizer is the smart contract which provides MoC trusted reference price.
It maintains a whitelist of price feed contracts which are allowed to post price updates and a record of recent prices supplied by each address. Every time a new price update is received the median of all feed prices is re-computed and the medianized value is updated.
Permissions
The adding and removal of whitelisted price feed addresses is controlled via governance, as is the setting of
the min parameter - the minimum number of valid feeds required in order for the medianized value to
be considered valid.
This is an job app that run on background, getting the price from different sources ponderate the final price and saving to price feeder contract.
Prices from exchanges, take a look to Prices source
First we need that the owner of the Oracle create a price feeder, this is created by governor of the Oracle (MoC Medianizer) contract.
We need some information first. The address of the account that are going to pay for gas.
Example: 0xfDB628524AD95c95a2C1f8dA9b8Bd92b6478CF6F you need to
control that account and have funds only to pay transaction gas.
The new price feeder is owned by the user and also have the contract address.
Requirement and installation
- Required Python 3.9
Install libraries
pip install -r requirements.txt
Also we need brownie installed
pip install eth-brownie==1.17.0
Add custom RSK Network connection
First we need to install custom networks (RSK Nodes) in brownie:
console> brownie networks add RskNetwork rskTestnetPublic host=https://public-node.testnet.rsk.co chainid=31 explorer=https://blockscout.com/rsk/mainnet/api
console> brownie networks add RskNetwork rskTestnetLocal host=http://localhost:4444 chainid=31 explorer=https://blockscout.com/rsk/mainnet/api
console> brownie networks add RskNetwork rskMainnetPublic host=https://public-node.rsk.co chainid=30 explorer=https://blockscout.com/rsk/mainnet/api
console> brownie networks add RskNetwork rskMainnetLocal host=http://localhost:4444 chainid=30 explorer=https://blockscout.com/rsk/mainnet/api
Connection table
| Network Name | Network node | Host | Chain |
|---|---|---|---|
| rskTestnetPublic | RSK Testnet Public | https://public-node.testnet.rsk.co | 31 |
| rskTestnetLocal | RSK Testnet Local | http://localhost:4444 | 31 |
| rskMainnetPublic | RSK Mainnet Public | https://public-node.rsk.co | 30 |
| rskMainnetLocal | RSK Mainnet Local | http://localhost:4444 | 30 |
Usage Job
There are many networks already preconfigurated see enviroments/ folder.
export ACCOUNT_PK_SECRET=(Your PK)
python app_run_price_feeder.py --connection_network=rskTestnetPublic --config_network=mocTestnet --config ./enviroments/moc-testnet/config.json
Note: Replace (Your PK) with your private key owner of the account.
--config: Path to config.json or json content (string)
--connection_network=rskTestnetPublic: Network connection name
--config_network=mocTestnet: config_network reference to network in the config.
Build, change path to correct environment
docker build -t price_feeder -f Dockerfile --build-arg CONFIG=./enviroments/rdoc-testnet/config.json .
Run, replace ACCOUNT_PK_SECRET with your private key owner of the account
docker run -d \
--name price_feeder_1 \
--env ACCOUNT_PK_SECRET=asdfasdfasdf \
--env APP_CONNECTION_NETWORK=rskTestnetPublic \
--env APP_CONFIG_NETWORK=rdocTestnet \
price_feeder
APP_CONNECTION_NETWORK: https://public-node.testnet.rsk.co,31