Ethereum Sample

Prerequisites

Java (tested with java8)

Node (tested with 9.11.1)

git (apt-get install git-core)

Python 2.X (Sudo apt install python-minimal)

GCC (Sudo apt install gcc)

build-essential (sudo apt-get install build-essential)

Maven (Sudo apt-get install maven)

Setup Environment

Install Docker

Install Geth

sudo apt-get upgrade
sudo apt-get install -y build-essential
sudo apt-get install git
cd ~
git clone https://github.com/ethereum/go-ethereum.git

cd ~
wget https://dl.google.com/go/go1.9.3.linux-amd64.tar.gz
sudo tar -C /usr/local -xzf go1.9.3.linux-amd64.tar.gz
add to ~/.profile : export PATH="$PATH:/usr/local/go/bin"

cd ~
cd go-ethereum
make geth

• Install SolC

Npm install -g solc

• Install Web3J

Npm install -g web3

Run application

1. Running Ethereum

Fron the ethereum folder, run ./runminer.sh to start the miner node. Check the logs by running docker ps to get the container ID and then docker logs CONTAINER_ID -f. When the DAG generation process has finished and the logs say 'commit new mining work', run ./runattach.sh to open RPC connection with the miner node. Generating DAG usually takes a while.

2. Spin up database

docker run --name some-postgres -e POSTGRES_PASSWORD=postgres -p 5432:5432 -d postgres

3. Start the Springboot app

4. Deploy smart contract

From the contracts folder, run

./redeploy-contract.sh

5. Test API

POST to localhost:9000/register-user to create a user (request body: { "username":"Bob", "password":"some-password"}

POST to localhost:9000/ to create a contract (request body: {"creator":"Bob", "coach":"coach","coachee":"coachee"}. Make sure the creator has an account (so Bob in this case)

GET to localhost:9000?username=Bob to get the coachee from the smart contract (again make sure to pass the name of the creator of the contract, which is Bob here)

Teardown

From src/ethereum run

./wipeall.sh

The ethereum-part is an (over)simplification of https://github.com/vertigobr/ethereum