Descartes SDK Environment

Section Goal
  • describe easy-to-use environment available for developing Descartes DApps
  • download and run the environment

Overview

As described in detail in the Descartes SDK section, a Descartes DApp requires that a certain set of components and resources be available in order to effectively run. There are numerous alternative topologies in which this architecture can be deployed depending on the users' interests and resources. Moreover, the DApp can also choose from a range of supported blockchain networks on which the Descartes smart contracts are deployed and available.

However, for the purposes of these tutorials (and general rapid Descartes DApp prototyping), the Cartesi team has provided a ready-to-use Descartes SDK Environment with all the on-chain and off-chain components necessary to build a Descartes DApp out-of-the-box. This environment is configured for a scenario with two actors, denominated alice and bob, who will respectively perform the roles of claimer and challenger for all Descartes computations.

Components

The Descartes SDK Environment basically consists of a Docker Compose specification that spins up services corresponding to the components described below.

Local Descartes-enabled blockchain

The environment starts up a local blockchain network using Hardhat, which is accessible on port 8545. This network instance comes pre-installed with a number of user accounts, the first two of which we will use for alice and bob, with addresses respectively at 0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266 and 0x70997970C51812dc3A010C7d01b50e0d17dc79C8.

Moreover, the network is instantiated with all the Descartes smart contracts already deployed. As such, these smart contracts are readily available for our tutorial DApps to use.

Descartes nodes

For each of the two actors, alice and bob, the environment provides a corresponding off-chain Descartes node, which is responsible for carrying out computations on their behalf. In practice, each node is composed of a number of internal services, but DApp developers can safely abstract away these details completely.

Download and run

The Descartes SDK Environment is available on the Descartes Tutorials GitHub repo.

You can download and extract a ready-to-use artifact by executing:

wget https://github.com/cartesi/descartes-tutorials/releases/download/v1.1.0/descartes-env-1.1.0.tar.gz
tar -xzvf descartes-env-1.1.0.tar.gz

Then, start it up by running:

cd descartes-env
docker-compose up

This will print the logs of all services in your current terminal. As such, you will normally need to open up a separate terminal in order to follow the next sections of this tutorial.

Alternatively, you may run the above docker-compose command in detached mode by adding the -d switch. In this case, it can be useful to list the currently instantiated services by executing the docker ps command, and then check the output printed by each service by running docker logs <service>. Please refer to the Docker documentation for a complete overview on how to use Docker and Docker Compose.