Python3.7

Docker

PyTezos requires some libraries pre-installed. See their quickstart for instructions.

Kaiko API Key

Create a virtual python environment and activate it.

? python3 -m venv .env
? source .env/bin/activate

(.env) ? which pip 
/kaiko/.env/bin/pip

Now you can install requirements without polluting your global python dependencies.Use source .env/bin activate to activate the environment every time you want to use the repo locally. To leave the environment, use deactivate.

(.env) ? pip install -r requirements.txt

Your environment variables file can be used both for running locally and for running docker. See env-example. Note that for docker to parse the variables correctly, you cannot have whitespace or quotes.

Create one env file per feed.

To run the Tezos Sandbox to develop and test locally, use docker run -it -d -p 127.0.0.1:18731:18731 nomadiclabs/tezos-sandbox:py --time-between-blocks 7 and set ENV=http://localhost:18731 in your env file.

The contract included in contract/oracle_contract.tz stores values for each feed as a pair of timestamp and nat value. In api.py, you can see how the results are parsed, and the price value is transformed into nat. Other contract storage types and supporting other transformations than just btc -> satoshi or usd -> cents can be done in this file.

This contract was created using lorentz-contract-oracle

$ stack exec -- lorentz-contract-oracle Oracle print --valueType "(pair timestamp nat)" --oneline

To create a contract on your local sandbox, you can use lorentz-contract-oracle, replacing [bracketed values] with your own:

$ tezos-client --wait none originate contract BTCXTZ transferring 0 from "[public key]" running "$(<[path/to/repo]/contract/oracle_contract.tz)\" --init "$(stack exec -- lorentz-contract-oracle Oracle init --initialValueType "(pair timestamp nat)" --initialValue "(Pair 0 0)" --admin \"[public key]\")" --burn-cap 0.712

Save the KT1 contract address generated in your env file as ORACLE_ADDRESS=KT1...

With env file created, you can start the flask app as follows:

(.env)$ export $(xargs <env)
(.env)$ flask run

The server should start, and you can make individual requests for oracle updates by hitting localhost:5000. A task that updates the oracle contract every 60 seconds with API data will also start.

Build

docker build -t kaiko-oracle:latest .

Run:

docker run -d -p 5000:5000 --env-file=[your-env-file] kaiko-oracle

Build and run:

docker build -t kaiko-oracle:latest . && docker run --rm -it -p 5000:5000 --env-file=[your-env-file] kaiko-oracle

For Mainnet deployments, you may want to think about using something more secure than environment variables for your secret keys. Docker swarm provides secrets that cannot be revealed inadvertently by logging the environment. https://docs.docker.com/engine/swarm/secrets/