Perun Node - Go implementation

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Perun is an open source project that aims to increase blockchain transaction throughput by using just a handful of main chain transactions to move an entire peer-to-peer network of activity off the main chain. After an initial setup of a set of basic transaction channels, this network lets any participant transact with any other participant via virtual channels which do not require additional on-chain setup. We do this by implementing the Perun protocol, which has been formally proven to allow for secure off-chain transactions.

Project Status

At the moment the perun-node is neither ready for production nor does it implement the complete perun protocol yet. But with basic features available, the project is at a stage where you can try it out and start to get involved.

This is a complete re-implementation of the previous version (available under the previous name of the project: dst-go) in branch legacy/master. This version builds on top of the go-perun SDK that implements a state channel client based on perun protocol. See Description for more details.

Description

The perun-node is multi-user state channel node that can be used for opening, transacting on and closing state channels. It builds on the state channel client implemented by go-perun and implements the following functionalities:

1. Payment App: For using perun protocol to establish and use bi-directional payment channels.
2. ID Provider: For the user to define a list of known participants in the off-chain network.
3. Key management: For managing the cryptographic keys of the user.
4. User session: For allowing multiple users to use a single node, each with a dedicated key manager and ID provider.
5. User API interface: For the user to interact with the perun-node.

The current version provides the following features:

Feature	Implementation
Blockchain Backend	Ethereum
Key management	Ethereum keystore
ID Provider	Local
User API	Two Party Payment API
User API Adapter	gRPC
Persistence	LevelDB
Currencies	ETH, Any ERC20 token

This project currently contains three executable packages located in the cmd directory.

• perunnode: An app for starting a running instance of perun node. It can also generate configuration artifacts for trying out the node.

• perunnodecli is an app with interactive CLI interface that serves two purposes:

  • easy way to try out payment channel API.
  • reference implementation for using the generated grpc client stubs for payment channel API.

• perunnodetui is an app with interactive text based user interface. With visual representation most of the actions, it is easy way to try out payment channel API and understand the perun protocol.

For a tutorial on using perun-node with perunnodecli, see the tutorial section on the project documentation website.

For a tutorial on using perun-node with perunnodetui, see this section. A talk on overview of perun, including a hands-on demo of using the perunnode with perunnodetui can be found here.

Getting Started

Install the following pre-requisites.

1. Go (v1.19 or later).
2. ganache-cli (v6.9.1 or later).

Clone the project and sync the dependencies:

git clone https://github.com/hyperledger-labs/perun-node.git
cd perun-node
go mod tidy

Start the ganache-cli node for running integration tests:

# These funded accounts will be used in tests. "-b 1" configures the
# ganache-cli node to mine one block every second. It is required as our
# contracts use blockchain based timeout for settling a state channel on-chain.
ganache-cli -b 1 \
--account="0x1fedd636dbc7e8d41a0622a2040b86fea8842cef9d4aa4c582aad00465b7acff,100000000000000000000" \
--account="0xb0309c60b4622d3071fad3e16c2ce4d0b1e7758316c187754f4dd0cfb44ceb33,100000000000000000000"

Run the linter and tests from the project root directory:

# Lint
golangci-lint run ./...

# Test
go test -tags=integration -count=1 -p=1 ./...

# Build perunnode and perunnodecli binaries
make

License

perun-node is open-sourced under the Apache-2.0 license. See the LICENSE file for details.