Description

This repo includes the Truffle configuration files needed for deploying a smart contract either to a local blockchain generated by Ganache, or to the Ropsten Test Network.

Only the needed files are uploaded here. You will have to initialize a truffle project first, and then copy the contents of this repo inside it.

A sample smart contract is also included.

You can find the deployed contract on Ropsten at 0xb40857c01d2cb956b9f3e2cccd0190a56a1d3a31.

Instructions (for Linux based systems)

• Install Truffle:

sudo apt install npm # Replace 'apt' with your distribution's package manager if needed
sudo npm install -g truffle

• Download the Ganache .AppImage from here and make it executable:

chmod +x Ganache-2.0.0.AppImage # Your version might be different

• Create a new project directory, initialize an empty truffle project and install truffle-hdwallet-provider:

mkdir my_truffle_project && cd my_truffle_project
npm init # Optional: Spam the enter key to accept the default/empty values.
truffle init
npm install truffle-hdwallet-provider

• Clone this repo somewhere and copy the files inside your project directory:

git clone https://github.com/elenapan/truffle-lab.git
cp -r truffle-lab/* /path/to/my_truffle_project

• Install Metamask on your browser, create a Metamask wallet and save your mnemonic (12 word string) somewhere.

• Register an account on Infura and create a new project.

• Edit truffle-config.js in your project directory and paste your own mnemonic and Infura endpoint in the respective variables (remove the < and >):

// Place your own mnemonic here
var mnemonic = "<YOUR 12 WORD MNEMONIC HERE: orange apple banana ...>";
// Place your own infura endpoint URL for Ropsten here
var infura_endpoint = "https://ropsten.infura.io/v3/<YOUR INFURA PROJECT ID HERE>"

• Request some Ether on the Ropsten Ethereum Faucet by pasting your address generated by Metamask in the input box.

Deployment

After following the instructions above, you should be ready to deploy your smart contract.

Assuming that you are inside your project directory:

Deploying on Ganache

• Launch Ganache:

/path/to/your/Ganache-2.0.0.AppImage

• Compile contract:

truffle compile

• Deploy contract:

truffle migrate

or

truffle deploy

The two commands above are equivalent.

Note: You can use the flags --reset --all in order to force truffle to compile your contract from scratch before deploying (regardless whether it is needed or not).

truffle deploy --reset --all

• Run console

truffle console

Deployment on Ropsten Test Network

• Compile contract:

truffle compile

• Deploy contract:

truffle migrate --network ropsten

or

truffle deploy --network ropsten

• Run console

truffle console --network ropsten

Cheatsheet for Truffle console

• Get accounts:

accounts = await web3.eth.getAccounts()

• Print accounts:

accounts

• Print specific account (e.g. 4):

accounts[4]

• Init contract instance:

c = await MyContract.deployed()

• Get contract address

c['address']

• Access public variables with their getter method:

await c.posts(0)

• Call functions:

await c.createNewPost("some title", "some url")
await c.createNewPost("some title", "some url", {from: accounts[3], gas: 400000})
await c.getNumberOfPosts()

Tools / Frameworks / Services used in this lab

• Truffle
• Ganache
• Metamask (optional)
• Infura
• Ropsten Ethereum Faucet
• Ropsten Etherscan

Useful links

• Solidity Documentation
• web3.js Documentation
• Cryptozombies: Online Solidity Course
• Contract Oriented Programming I (old but still useful)
• Contract Oriented Programming II
• Truffle Boxes (Templates)
• Truffle Tutorial: Pet shop
• Truffle: Deploy contracts using Infura