The Blockchain Bar

The source-code for: "Build a Blockchain from Scratch in Go" eBook.

📚 Get the eBook from: https://gumroad.com/l/build-a-blockchain-from-scratch-in-go

Table of Contents

• TBB Training Ledger
  • Sneak peek to Chapter 13
    • 1/4 Check the current blockchain network status
    • 2/4 Download the pre-compiled blockchain program
      • Install
        • Download
          • Linux
          • MacOS
        • Verify the version
    • 3/4 Connect to the training network
    • 4/4 Check the current blockchain network status
• Introduction
  • How?
  • What will you build?
    • 1) You will build a peer-to-peer system from scratch
    • 2) You will secure the system with a day-to-day practical cryptography
    • 3) You will implement Bitcoin, Ethereum and XRP backend components
    • 4) You will write unit tests and integration tests for all core components
  • How to use this repository
  • Installation
  • Getting started
• Usage
  • Install
  • CLI
    • Show available commands and flags
      • Show available run settings
    • Run a TBB node connected to the official book's test network
    • Run a TBB bootstrap node in isolation, on your localhost only
      • Run a second TBB node connecting to your first one
    • Create a new account
  • HTTP
    • List all balances
    • Send a signed TX
    • Check node's status (latest block, known peers, pending TXs)
  • Tests
• Start
  • Tutorial
• Finish
  • Request 1000 TBB testing tokens

TBB Training Ledger

Sneak peek to Chapter 13

You will build all of this from scratch! Follow the next 4 steps and you will be connected to the TBB testing blockchain network in 30 seconds.

1/4 Check the current blockchain network status

Go ahead. Try it right now! 💘

curl https://node.tbb.web3.coach/balances/list

In case you have the JQ - CLI JSON processor formatter. installed.

curl https://node.tbb.web3.coach/balances/list | jq

{
  "block_hash": "000000a9d18730c133869d175a886d576df5675e0e73900bf072c59047b9d734",
  "balances": {
    "0x09ee50f2f37fcba1845de6fe5c762e83e65e755c": 1000095,
    "0x22ba1f80452e6220c7cc6ea2d1e3eeddac5f694a": 5
  }
}

2/4 Download the pre-compiled blockchain program

Together with all students, we will use this custom build blockchain for educational purposes.

Install

Download

Linux

wget "https://github.com/web3coach/the-blockchain-bar/releases/download/1.3.1-alpha/tbb-linux-amd64" -O /usr/local/bin/tbb

Verify the version

chmod a+x /usr/local/bin/tbb
tbb version

> Version: 1.2.1-alpha TBB Training Ledger - HTTPS

3/4 Connect to the training network from localhost

tbb run --datadir=$HOME/.tbb --ip=127.0.0.1 --port=8081 --disable-ssl

Your blockchain database will synchronize with rest of the students.

Launching TBB node and its HTTP API...
Listening on: 127.0.0.1:8081
Blockchain state:
	- height: 0
	- hash: 0000000000000000000000000000000000000000000000000000000000000000

Searching for new Peers and their Blocks and Peers: 'node.tbb.web3.coach'
Found 1 new blocks from Peer node.tbb.web3.coach
Importing blocks from Peer node.tbb.web3.coach...

Persisting new Block to disk:
	{"hash":"000000a9d18730c133869d175a886d576df5675e0e73900bf072c59047b9d734","block":{"header":{"parent":"0000000000000000000000000000000000000000000000000000000000000000","number":0,"nonce":1925346453,"time":1590684713,"miner":"0x09ee50f2f37fcba1845de6fe5c762e83e65e755c"},"payload":[{"from":"0x09ee50f2f37fcba1845de6fe5c762e83e65e755c","to":"0x22ba1f80452e6220c7cc6ea2d1e3eeddac5f694a","value":5,"nonce":1,"data":"","time":1590684702,"signature":"0JE1yEoA3gwIiTj5ayanUZfo5ZnN7kHIRQPOw8/OZIRYWjbvbMA7vWdPgoqxnhFGiTH7FIbjCQJ25fQlvMvmPwA="}]}}


Searching for new Peers, Blocks: 'node.tbb.web3.coach'
Searching for new Peers, Blocks: 'node.tbb.web3.coach'

4/4 Check the current blockchain network status

This time from your OWN, fully synchronized blockchain node running directly on your computer.

curl -X GET http://127.0.0.1:8081/balances/list | jq

{
  "block_hash": "000000a9d18730c133869d175a886d576df5675e0e73900bf072c59047b9d734",
  "balances": {
    "0x09ee50f2f37fcba1845de6fe5c762e83e65e755c": 1000095,
    "0x22ba1f80452e6220c7cc6ea2d1e3eeddac5f694a": 5
  }
}

⭐ All of this and much more, you will build from scratch!

Introduction

Hi 👋,

With Web 3.0 and blockchain becoming more mainstream every day, do you know what blockchain is? Do you know its technical advantages and use-cases?

The goal of this tutorial is to introduce blockchain technology from a technical perspective by building one from scratch.

Forget everything you've heard about blockchain from social media. Now, you will build a blockchain system from ground zero to really understand the ins and outs of this peer-to-peer, distributed technology.

Afterwards, make your own mind up about its future, advantages and shortcomings.

Spoiler alert: you will fall in love with programming blockchain software. 😈

How?

You will follow the story of a software developer who is looking to revolutionize his local bar by implementing blockchain technology for its payment system.

Although blockchain has several undeniable use-cases, at the moment, the number one application is payments. This is because banks are still running on an inefficient, 40 year old infrastructure powered by CSV files and FTP.

The story comes with a lot of fun and intriguing facts about the overall blockchain ecosystem and different protocols such as Bitcoin, Ethereum and XRP.

What will you build?

Chapter by chapter, you will build a full peer-to-peer, autonomous training blockchain system in Go and learn all standard blockchain components!

Note: This codebase is only for educational (training, learning) purposes. Do not use this code in production.

1) You will build a peer-to-peer system from scratch

You start with 0 lines of code and end-up with 13+ branches with complete executable source-code.

PS: Don't worry if anything on the screen makes sense yet, it will once you go chapter by chapter; release by release.

2) You will secure the system with a day-to-day practical cryptography

No boring theory. Only modern practices.

3) You will implement Bitcoin, Ethereum and XRP backend components

From diagrams of mining algorithms to actual, implemented and working crypto wallets for storing the mined tokens and all other fundamental components that make blockchain special.

4) You will write unit tests and integration tests for all core components

You will test your cryptographic functions, a Bitcoin's like Proof of Work mining algorithm and other key components.

How to use this repository

Every eBook chapter has a dedicated branch where you can experiment with the code first-hand.

git pull --all
git branch

> c1_genesis_json
> c2_db_changes_txt
> c3_state_blockchain_component
> c4_caesar_transfer
> c5_broken_trust
> c6_immutable_hash
> c7_blockchain_programming_model
> c8_transparent_db
> c9_tango
> c10_peer_sync
> c11_consensus
> c12_crypto
> c13_training_network
> c14_why_transaction_costs_gas

Installation

Open instructions.

Getting started

1. Download the eBook from: https://gumroad.com/l/build-a-blockchain-from-scratch-in-go
2. Open the book at Chapter 1
3. Checkout the first chapter's branch c1_genesis_json

git pull --all

git checkout c1_genesis_json

Usage

Install

go install ./cmd/...

CLI

Show available commands and flags

tbb help

Show available run settings

tbb run --help

Launches the TBB node and its HTTP API.

Usage:
  tbb run [flags]

Flags:
      --bootstrap-account string   default bootstrap Web3Coach's Genesis account with 1M TBB tokens (default "0x09ee50f2f37fcba1845de6fe5c762e83e65e755c")
      --bootstrap-ip string        default bootstrap Web3Coach's server to interconnect peers (default "node.tbb.web3.coach")
      --bootstrap-port uint        default bootstrap Web3Coach's server port to interconnect peers (default 443)
      --datadir string             Absolute path to your node's data dir where the DB will be/is stored
      --disable-ssl                should the HTTP API SSL certificate be disabled? (default false)
  -h, --help                       help for run
      --ip string                  your node's public IP to communication with other peers (default "127.0.0.1")
      --miner string               your node's miner account to receive the block rewards (default "0x0000000000000000000000000000000000000000")
      --port uint                  your node's public HTTP port for communication with other peers (configurable if SSL is disabled) (default 443)

Run a TBB node connected to the official book's test network

If you are running the node on your localhost, just disable the SSL with --disable-ssl flag.

tbb version
> Version: 1.2.1-alpha TBB Training Ledger - HTTPS

tbb run --datadir=$HOME/.tbb --ip=127.0.0.1 --port=8081 --miner=0x_YOUR_WALLET_ACCOUNT --disable-ssl

Run a TBB bootstrap node in isolation, on your localhost only

tbb run --datadir=$HOME/.tbb_boostrap --ip=127.0.0.1 --port=8080 --bootstrap-ip=127.0.0.1 --bootstrap-port=8080 --disable-ssl

Run a second TBB node connecting to your first one

tbb run --datadir=$HOME/.tbb --ip=127.0.0.1 --port=8081 --bootstrap-ip=127.0.0.1 --bootstrap-port=8080 --disable-ssl

Create a new account

tbb wallet new-account --datadir=$HOME/.tbb 

Run a TBB node with SSL

The default node's HTTP port is 443. The SSL certificate is generated automatically as long as the DNS A/AAAA records point at your server.

Official Testing Bootstrap Server

Example how the official TBB bootstrap node is launched. Customize the --datadir, --miner, and --ip values to match your server.

/usr/local/bin/tbb run --datadir=/home/ec2-user/.tbb --miner=0x09ee50f2f37fcba1845de6fe5c762e83e65e755c --ip=node.tbb.web3.coach --port=443 --ssl-email=lukas@web3.coach --bootstrap-ip=node.tbb.web3.coach --bootstrap-port=443 --bootstrap-account=0x09ee50f2f37fcba1845de6fe5c762e83e65e755c

HTTP

List all balances

curl http://localhost:8080/balances/list | jq

Send a signed TX

curl --location --request POST 'http://localhost:8080/tx/add' \
--header 'Content-Type: application/json' \
--data-raw '{
	"from": "0x22ba1f80452e6220c7cc6ea2d1e3eeddac5f694a",
	"from_pwd": "security123",
	"to": "0x6fdc0d8d15ae6b4ebf45c52fd2aafbcbb19a65c8",
	"value": 100
}'

Check node's status (latest block, known peers, pending TXs)

curl http://localhost:8080/node/status | jq

Tests

Run all tests with verbosity but one at a time, without timeout, to avoid ports collisions:

go test -v -p=1 -timeout=0 ./...

Run an individual test:

go test -timeout=0 ./node -test.v -test.run ^TestNode_Mining$

Note: Majority are integration tests and take time. Expect the test suite to finish in ~30 mins.

Start

Tutorial

📚 Get the eBook from: https://gumroad.com/l/build-a-blockchain-from-scratch-in-go

Finish

Request 1000 TBB testing tokens

Write a tweet and let me know how did you like this book! Tag me in it @Web3Coach and include your account address 0xYOUR_ADDRESS.

See you on Twitter - @Web3Coach.

License

The the-blockchain-bar library (i.e. all code outside of the cmd directory) is licensed under the GNU Lesser General Public License v3.0, also included in our repository in the COPYING.LESSER file.

The the-blockchain-bar binaries (i.e. all code inside of the cmd directory) is licensed under the GNU General Public License v3.0, also included in our repository in the COPYING file.