paynecoin (PYN)

This repository contains the code for running 2 toy blockchains that allows you to record transactions. One is paynecoin-lite, a local private ledger, and the other is paynecoin-full, a decentralized distributed ledger. Both are made-up cryptocurrencies and are only for educational purposes.

Note

All instructions in this repository assume you have access to a Unix machine (macOS or Linux). See this section if you only have access to a machine with Windows.

• 1. Installation
  • 1.1. Conda
  • 1.2. Poetry
  • 1.3. Windows Support
    • 1.3.1. Windows Subsystem for Linux
    • 1.3.2. Cygwin
• 2. Running the paynecoin-lite blockchain
• 3. Running the paynecoin-full blockchain

1. Installation

Simply clone this repository to your machine to install. For example, you can clone this repository to your home directory by running

cd ~
git clone git@github.com:jepayne/paynecoin.git # SSH (recommended), or
git clone https://github.com/jepayne/paynecoin.git # HTTPS

This will download the paynecoin folder to your home directory. This is a python project, so you will also need to have a python executable with the proper dependencies installed.

You will need a working Python 3.5+ installation. I assume you already have one working, but if not, I recommend installing Anaconda.

If you already know how to manage your Python environments and packages, you can skip the following subsection. Just make sure you install the dependencies listed in pyproject.toml (i.e., using conda or pip with a virtual environment).

Everything going forward will assume that you are working from a shell where the python executable has the correct dependencies installed (for example, this is the case if you activate the poetry shell as described below, or if you have activated a conda environment that has the appropriate dependencies installed).

1.1. Conda

If you have an Anaconda python installation, you can create an environment, activate the environment, install the dependencies listed in pyproject.toml, and then you will be able to run everything without a hitch.

1.2. Poetry

Poetry is one way to easily manage packages and environments.

1. Follow the installation instructions to set Poetry up in your machine. You can verify that the installation was successful by running the following command in a terminal without any errors:

poetry --version

2. Navigate to the local copy of this repository and install the defined dependencies for this project. For example, if you cloned the project to your home directory, run

cd ~/paynecoin
poetry install

3. activate the project's Python virtual environment by spawning a new shell:

poetry shell

1.3. Windows support

From Windows, everything except the utilities provided by paynecoin-full/paynecoin_nodes.sh will work as normal. You can still initialize blockchain nodes manually on Windows (as on Unix systems) by running paynecoin-full/api.py with the appropriate command line arguments. Look at paynecoin-full/README.md for more details on initializing blockchain nodes.

1.3.1. Windows Subsystem for Linux

If you have a Windows machine, one elegant way to run all the code from this repository is to install the Windows Subsystem for Linux (WSL). This will give you a Unix terminal that has access to files on your Windows machine. You can then install a python executable in the WSL (for example, using the wget command to download the Anaconda installation script) and proceed as if you were using Unix. If you are committed to using Windows and plan to do a lot of software development, this is a good tool to be familiar with.

1.3.2 Cygwin

Another option is to use Cygwin. If you choose to go this route, you will need to do the following:

1. Run sed -i 's/\r//' paynecoin_nodes.sh from cygwin to change the format of the script. Then, bulk initialization of nodes will work as described elsewhere.
2. Running ps -W | grep payne | awk '{print $1}' | while read line; do echo $line | xargs kill -f; done; will kill nodes in bulk (usually, sometimes this is buggy)
3. netstat -ano | findstr :<port_number> (find the PIDs of the processes using these ports) and taskkill /PID <pid> -f (kill the processes once you have the PIDs) will work to kill nodes individually.

2. Running paynecoin-lite

Look at the paynecoin-lite readme for motivation, possible homework 2 questions, and example code.

For a very quick start, navigate to the paynecoin-lite subfolder (e.g. cd ~/paynecoin/paynecoin-lite) and run the following in your (poetry) shell:

python simulation.py

3. Running paynecoin-full

Look at the paynecoin-full readme for motivation, possible homework 3 questions, and example code.

For a very quick start, navigate to the paynecoin-full subfolder (e.g. cd ~/paynecoin/paynecoin-full) and run the following in your (poetry) shell:

bash paynecoin_nodes.sh init 5
python simulation.py
bash paynecoin_nodes.sh kill