teejays / copperchain

A simple blockchain implementation in Go.

CopperChain

CopperChain implements a basic blockchain in Golang. It treats blockchain as a package, which can be imported by other packages and used. It also has the optional functionality of a web server, which provides basic Get and Post endpoints.

Click here for code documentation.

Getting Started

Prerequisites:

1. Install Golang. You can install it from the official Go website.
2. Install the following Go packages (if you don't have them already):
   • GoFiledb: A micro, very easy to use, DB client that uses filesystem for storage. To install, run: go get -u github.com/teejays/gofiledb
   • Gorilla Mux: A powerful URL router and dispatcher for golang. To install, run: go get -u github.com/gorilla/mux

Usage:

First, install CopperChain by running in your command line:

go get -u github.com/teejays/copperchain

After this, CopperChain can be included in your package easily. Add the following import statement to the go file which needs to use the package:

import github.com/teejays/copperchain

Before you interact with CopperChain, you need to initialize it. You can initialize it by calling the Init() function, that accepts optional parameters.

// Init Copper Chain
copperchain.Init(copperchain.Options{})

Once initialized, you can get the existing blockchain by calling the GetCopperChain() method.

chain := copperchain.GetCopperChain()

You can add a block to the blockchain by calling the AddToCopperChain() method, which requires a parameter of the form map[string]interface. This allows for flexibility of data that can be kept in the block.

data := make(map[string]interface{})
data["transaction_id"] = "abc123"
err := copperchain.AddToCopperChain(data)

If you want to set up the blockchain as RESTful API, you can call the RunSerever() method, which takes some options around the server address on which to rum the server.

err := copperchain.RunServer(copperchain.ServerOptions{
		Host: "127.0.0.1", //optional
		Port: 8080, // default 8080
	})

Example Code

Here is an example code that demonstrates the use of CopperChain. It can also be found at example.go.

package main

import (
	"fmt"
	"github.com/teejays/copperchain"
	"log"
)

func main() {

	// Init CopperChain
	copperchain.Init(copperchain.Options{
		DataRoot: ".data", 
	})
	
    	// Get CopperChain
	chain := copperchain.GetCopperChain()
	fmt.Printf("Chain: %+v\n", chain)

	// Add block data to chain (data should always be a map[string]interface{})
	var data map[string]interface{} = make(map[string]interface{})
	data["some_key"] = "the_value"
	copperchain.AddToCopperChain(data)

	// Check that the changes are reflected
	chain = copperchain.GetCopperChain()
	fmt.Printf("Chain: %+v\n", chain)
    
	// (optional) Run Server
	err = copperchain.RunServer(copperchain.ServerOptions{
		Host: serverHost,
		Port: serverPort,
	})
	if err != nil {
		log.Fatal(err)
	}

}

To manually run the provided example, download the example code locally, build it and run it:

go build -o example
./example

API Endpoints

If you decide to run the built-in webserver, it will listen on two endpoints:

1. HTTP GET /
   • provides the entire chain
   • curl example: curl http://localhost:8080/
2. HTTP POST /
   • accepts a json object as body, which can be parsed into a map[string]interface{}
   • curl example: curl http://localhost:8080/ -H "Content-Type: application/json" -d '{"transaction_id":"abc123"}'

Contact

For any issues, please open a new issue. If you want to contribute, please feel free to submit a merge request or reach out to me at [email protected].