kilyig/blockchainnetwork

A P2P blockchain network from scratch, written in Go.

BlockchainNetwork

A P2P blockchain network from scratch, written in Go.

Installation and Usage

First, clone this repository:

git clone https://github.com/kilyig/BlockchainNetwork.git

The command line programs are in cmd. To start a node from the root directory, run

go run cmd/node/node.go --node-addr [address + port of this node] [address + port of each node that this node will communicate with]*

For example, if our node is at [::1]:8080 and communicates with nodes at addresses [::1]:8081 and [::1]:8082, then we would run

go run cmd/node/node.go --node-addr [::1]:8080 [::1]:8081 [::1]:8082

In this scenario, [::1]:8080 will try to sychronize its blockchain with [::1]:8081 and [::1]:8082. To start a miner from the root directory, run

go run cmd/miner/miner.go --miner-name [a name for this miner] --mine-delay [delay (nanoseconds) before checking a block while mining] [address + port of each node that this miner will communicate with]*

For example, if a miner named tosun stops for 100 nanoseconds before each block and communicates with nodes at addresses [::1]:8080 and [::1]:8081, then we would run

go run cmd/miner/miner.go --miner-name tosun --mine-delay 100 [::1]:8080 [::1]:8081

The --mine-delay parameter helps us simulate miners with different hash powers.

observer.go can be used to check if everything is going well. It prints the last block of the node provided by the parameter --node-addr:

go run cmd/observer/observer.go --node-addr [::1]:8081

Note: launch_nodes.sh and launch_miners.sh might be worth checking out but they do not currently support networking.

Using the Docker containers

In the root directory, run

docker build -t node -f Dockerfile.node .
docker build -t miner -f Dockerfile.miner .

to build the Docker containers for nodes and miners. Docker containers currently support networks with any number of miners and at most one node. To run the node, run

docker run --network=host --rm -p 8080:8080 node

To run a miner connected to this node, run

docker run --network=host --rm -p 8080:8080 miner --miner-name name_of_this_miner [::1]:8080

Compiling the .proto code

The repo has already run the protobuf compiler to generate the proto code. If you want to do this on your own, you can do make to use the Makefile in the root directory. The Makefile runs the following command:

protoc --go_out=. --go_opt=paths=source_relative --go-grpc_out=. --go-grpc_opt=paths=source_relative node/proto/node.proto

You will need to install protoc, the protobuf compiler, to get started. You can find instructions in the gPRC documentation: https://grpc.io/docs/protoc-installation/ I highly suggest you to follow the instructions under "Install pre-compiled binaries (any OS)". The apt and apt-get on Linux install an older version, which is undesirable. Additionally, you will need to install the Go plugins, following these steps: https://grpc.io/docs/languages/go/quickstart/

Tests

The main testing method for the network was running the nodes and miners locally and checking the logs. The code comes with several basic tests for the blockchain data structure, but they do not have much coverage. To run them, navigate to blockchain/test and run

go test -run=Test -v