Singularity Network is my minimal implementation of a PoS based Blockchain, written in Python. This is my Bachelor Thesis project and it is available as an open source project on Github. It uses P2P communication in order to handle the decentralized aspect of the chain. The Lottery PoS system is done by using hash chaining and it has an API system for user communication - written using Flask

Formatting

Use default black installation.

Installing

Tools you need: Poetry, Python 3.9 After installing poetry run poetry install, and to install git hooks run command pre-commit install

Running

Generating Keys

Generate RSA Key pairs for genesis and set the path for them using the config keys genesis_public_key_path and genesis_private_key_path. A node needs only the genesis public key. You use the private key to make a genesis transaction.

Wallet keys file name format is {wallet_name}_PrivateKey.pem and {wallet_name}_PublicKey.pem and reads from the folder specified by wallet_keys_folder. By default, it generates new keys and writes them to those files. Wallets belonging to nodes have the wallet_name as # and it always generates new keys.

Running a node

Running a node from command line

Project Root Folder is BlockChain First you have to start the origin node, and then other nodes. Otherwise, child nodes will not connect to the origin.

Run with command: python3 -m BlockChain.Application <ipaddr> <port> <apiport> <origin_ipaddr> <origin_port> [publickeypath] [privatekeypath]

Running a node with docker

First you have to build the image yourself by using docker build --tag <name>:<tag> ..

By default, origin_ip is specified using an environment variable in the Dockerfile, and by default it connects to the localhost of the local machine. This is specified using the name host.docker.internal. On linux when you use docker run you have to add the following option --add-host host.docker.internal:host-gateway.
The node ports and api ports by default are 10001 and 5000 respectively. These options can be overridden in settings.toml or by specifying environment variables at build time or run time. For more information check out https://www.dynaconf.com/envvars/.

You can run a node using docker run -p host-port:5000 -p host-port:10001 -d <name>:<tag>.
You first have to start the origin node and then other subsequent nodes specifying other host ports that are not already bound.

Running multiple nodes

Running multiple nodes with docker-compose

Build docker image with docker build --tag singularitycoin:latest . And then you can start the nodes with docker compose up -d. Only the origin node will be exposed on ports 10001 and 5000. The rest of the nodes are assigned random ports at the hosts, see the assigned ports using docker ps.