Getting Started with Ethereum Development. Slides from dev workshop at Blockchain Expo North America.

1. Developing Blockchain
Applications
November 28, 2018
getting started with ethereum

2. our goal today
1. Understand how Ethereum applications work
2. Understand the framework and how projects are structured
3. Write and deploy code

3. few questions before we start…
• Have you transacted ETH?
• Do you know what dapps are?
• Have you used a dapp?
• Have you written a smart contract or developed a dapp?

4. Part 1: Ethereum Architecture
and how do Ethereum apps work?

5. Some Definitions…
Ethereum
Network
Collection of nodes that transact Ether and store data
Node Any computer running the Ethereum client
Ethereum Client Piece of software that communicates with Ethereum
Network

6. Client-Server
Architecture

7. Tale of an ebay seller…
• Can the seller take their ratings
and feedback history and join
another online marketplace?
• Should they be able to?
• What’s the incentive for ebay
to make this possible?
• An ebay seller with excellent ratings
• ebay bans the seller for violation of their T&Cs
• Let’s assume that the seller was not at fault but they were
banned/suspended anyway

8. Centralized vs. Decentralized Apps
Centralized (Client-Server) Decentralized (Dapps)
Logic Cluster of servers contain the entire
logic.
All logic is contained in the contract. Once
the contract is mined, all nodes have the
exact same logic, saved on their copy of
the blockchain.
Data Integrity Maintained by strict set of rules
enforced by the infrastructure, tools,
and services.
Taken care via redundancy of the nodes in
the network.

9. Dapp Architecture

10. Dapp Architecture

11. Metamask
Metamask is a Google
Chrome extension that
makes Chrome an
Ethereum connected
browser.
https://metamask.io/

12. Getting Metamask
• Go to https://metamask.io/
• Get Chrome Extension
• Add to Chrome
• Launch Metamask and follow the setup
guide

13. Funding Metamask with Ether Click Buy

14. Funding Metamask with Ether

15. Donating back to Faucet

16. Mist
Browser
• https://github.com/eth
ereum/mist/releases
• Simply
download and
install the
executable for
your OS

17. Dapp Examples
Ethlance
Ethlance is a decentralized
freelancer platform for
the exchange of work for
Ether, rather than
traditional currencies.
https://ethlance.com/

18. Dapp Examples
Swarm City
Swarm City is a decentralized P2P sharing
economy. Some have called it Uber or
Craigslist on the blockchain. It requires
users to have a Swarm City Token in
order to pay for transactions in the
ecosystem.
https://swarm.city/

19. Dapp Examples
WeiFund
WeiFund is a crouwdsourcing app on the
Ethereum Ecosystem.
http://weifund.io/

20. Dapp Architecture

21. Dapp System Architecture

22. IPFS

23. How is Ethereum different from Bitcoin
blockchain?
Bitcoin Ethereum
Bitcoin uses a simple scripting system for
transactions. Bitcoin script is simple,
stack-based, and is intentionally not
Turing-complete, with no loops.
Ethereum platform is built with a Turing-
complete language.
Send bitcoin from Alice to Bob Send ether from Alice to Bob if…
• Bob’s balance is less than 2 eth
• Date > 2019/01/01

24. Ethereum Accounts
• External
• Contract

25. Part 2: Dev Setup
Install the tools and understand the framework

26. Ecosystem, tools, terms, products…
ETH Ethereum networks’ native crypto-currency
EVM Ethereum Virtual Machine providing decentralized computation service
Swarm Provides P2P file sharing and storage services
Whisper Protocol used by nodes to communicate with each other
Solidity, Serpent, LLL Smart contract programming languages
eth, geth, pyethapp Main ethereum software written in C++, Go, Python respectively.

27. Serverless Stack
Whisper Encrypted messaging protocol that allows nodes to send
messages directly to each other in a secure way; hides sender
and receiver identity from snoopers
Swarm P2P file sharing, similar to BitTorrent, but rewarded with
micropayments of ETH (Storage Layer)
Ethereum Virtual
Machine (EVM)
Runs the contract logic

28. There are many different Ethereum Networks
• One main Ethereum network – used for deployment of production
applications
• Test Networks – Ropsten, Rinkeby, Kovan
• Private Network on your own computer
• Create your own network and open it for others to use.

29. Test Networks
Ropsten • Resembles the main network
• Uses Proof of Work consensus algorithm
• Supported by Geth and Parity
• https://ropsten.etherscan.io/
Rinkeby • Uses Proof of Authority; you need to prove your existence (social media) to
retrieve ethers
• All ethers are already mined and only distributed on demand
• Supported by Geth
• https://rinkeby.etherscan.io/
Kovan • Uses Proof of Authority; requires Github account
• Supported by Parity
• https://kovan.etherscan.io/

30. Tools we need
Node Packet Manager
(npm)
NPM is a package manager for Node.js packages and modules
Ganache • Ethereum client for testing and development
• Runs locally and simulates a full Ethereum client
• Fast
• Well supported ecosystem of tools
Truffle • Dev environment, testing framework, and asset pipeline for
Ethereum
• Helps deploy contracts to the blockchain
• Help connect front-end to your deployed contracts
MetaMask • Ethereum light client
• Allows you to interact with Dapps via Chrome

31. Development workflow
1. Download and start an ethereum node
2. Code and compile your smart contract
3. Deploy your compiled contract on the network using a framework
like truffle
4. Call stuff in the contract using web3.js

32. NPM
• Download and install Node
https://nodejs.org/

33. Install Ganache
• https://truffleframework.com/ganache

34. Launch Ganache

35. Install Truffle
• https://truffleframework.com/truffle

36. Part 3: Code and Deploy
Code your first smart contract and deploy it on blockchain

37. Setting up your project
Ømkdir HelloEth
Øcd HelloEth
Øtruffle init

40. workflow
truffle compile This command compiles the contracts in your contracts folder and will
create artifacts (JSON files) that contain the bytecode that can be
executed on the network.
truffle migrate Deploy the contract on your test network. Migrations are scripts that follow a
series of steps that are needed to deploy your contracts and setup the projects
like you need them to setup.
truffle console To inspect the contract

42. workflow
truffle compile This command compliles the contracts in your contracts folder and will create
artifacts (JSON files) that contain the bytecode that can be executed on the
network.
truffle migrate Deploy the contract on your test network. Migrations are scripts that
follow a series of steps that are needed to deploy your contracts and
setup the projects like you need them to setup.
truffle console To inspect the contract

44. truffle migrate --reset

45. workflow
truffle compile This command compliles the contracts in your contracts folder and will create
artifacts (JSON files) that contain the bytecode that can be executed on the
network.
truffle migrate Deploy the contract on your test network. Migrations are scripts that follow a
series of steps that are needed to deploy your contracts and setup the projects
like you need them to setup.
truffle console To inspect the contract

46. Truffle 3
Truffle 2

47. Now that we can call() our contract, let’s create a
transaction that changes state.

51. Get a list of accounts

52. Get balance

53. Summary of what we did today
1. Understand how Ethereum applications work
2. Overview of the framework and a small sliver of tools in the
ecosystem
3. Wrote and deployed a smart contract

54. Thank you