Name: Libin Tom
Dockerhub repo: sh docker pull libintomkk/blockchain-app:latest

blockchain-project

Repo for the blockchain project in mcs cloud computing

1 - Create a digital wallet in metamask

Create an Ethereum account (public/private secp256k1 keypair with associated address) on Ethereum Goerli network with at least 100-bits of entropy.

Install metamask

• Download plugin from https://metamask.io/download/

Create account

• Click on the metamask entention in the browser extentions list to create a new digital wallet account

this will open up in a new tab and follow the onscreen instruction

• Select the goreli test network

Once the accout is created and logged in. Click on the right top network dropdown and click on the show/hide test network and turn the show test network ON Note: now you have your test netwrok listed in the Network dropdown

```sh select the Goreli test network

Your account should have 0 GoereliETH

```

Export Privat Key

• Click on the more options (3 dots) and Accout details
• Export private key

View account on ether scan

• Click on the more options (3 dots) and view account on ether scan

Export private key

• Click on the metamask account more options to show the private key > Store it safe some where

2 - Create an ERC20-compliant, fixed-supply token with the following parameters:

Creating a Security Audited, Production Ready ERC20 contract

In order to create an ERC20 contract that has been security audited, we will use one of the Open Zeppelin contracts. Open Zeppelin contracts are security audited best practices implementations. They are used throughout the industry. Their github is at the following address: * Refferance of the code in the ecr20.sol https://github.com/OpenZeppelin https://github.com/OpenZeppelin/openzeppelin-contracts/tree/master/contracts/token/ERC20 https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC2 0/ERC20.sol

Create Smart contract

Smart contract is code running on the blockchain. * smart contract is created using the Remix IDE (buit for the purose) * https://remix.ethereum.org/

• In remix, create a file with .sol extention (ex. erc20.sol)
• Copy the code from the erc20.sol to the new file in remix > This is fully working smart contract created using the OpenZeppelin > This smart contract stores a number on the blockchain and allows it to be retrieved

change the token name

• Inside the code just pasted find and modifiy the below mentioned variables with your token name and symbol to your desired one sh _name = "SHB_XXXXX"; _symbol = "SHB_XXXXX"; ## Compile smart contract
• Click on the compile tab and run the compiler in the solidiy compiler

Makesure to fix the errors if any and recompile until not errors

Deploy compiled smart contract

To the metamask digital wallet

• In environment select INJECTED PROVIDER - metamask
• Now select the account and approve it when the metamask pliggin will openup

View the transaction on etherscan

• In the right below terminal pannel of remix, find the transactoin status and link to ETHERSCAN, click on it to navigate

VERIFY

assuming you are in the etherscan

• Click in the CONTRACT tab (usually in the middle of the page)

• Click on the verify and publish

This will redirects to VERIFY AND PUBLISH CONTRACT SOURCE CODE

• Seave the contract address area as is with your deployed contract hash

• Select the compiler type SOLIDITY(single file)

• compiler version to the compiler used to compile in the remix (mostly 0.8.7+commit.e28d00a7)

• License type none

• click CONTINUE

Copy paste code to verify

• Copy the whole erc20.sol code from the remix and paste it in the ENTER THE SOLIDITY CONTRACT CODE BELOW

• scrol down.. make sure you are not a robot

Verify and Publish

This will verify and publish the block

scrol down and copy the ABI CONTRACT - CONTENT and store it in a file for now

3 - Deploy the token contract to the Ethereum Testnet (Goerli).

Import token to account

• Copy the transaction hash from the etherscan (to adderess)

• Open the metamask, click on the more option (3 dots) for expanded view

• Click on the ASSESTS of goerliETH accout (is it place below the account balance and next to activity)

• Click on the import tokens below

• Paste the token to TOKEN CONTRACT ADDRESS

his will automatically pull the symobl and token decimial we have deployed

4 - Build an application to transfer the token and eth

Application to transfer the token and eth over the api rather using the web console

• Create and activate a virtual environment for python packages ```sh sudo python -m venv nameofenv

source nameofenv/bin/activate * Install the python [requiremtns](https://github.com/libintomgit/blockchain-project/blob/main/requirements.txt) for the Web3 and python-decouple sh

install requiremtns using the requirements.txt file in this directory

pip install -r requirements.txt ```

• Create a web3 helper using the .env file (to manage value in different file ) ```sh # change the file name of DOTenv to .env

add the contract address created in the above step to CONTRACTADDRESS=patecontract_address

add the owner address to which the contract address was imported to OWNERADDRESS=pastetheowneraddress (find this in the metamask)

add the secret key of owner account to SUPERSECRETPRIVATEKEY=secretekey (find this in the metamask)

add the seed phrase of the account to SEEDPHRASE=seedwords (find this in the metamask)

leave the TARGET_ADDRESS= blank and commented as we provide this in the API later

add the abi generated from the goerli.etherescan contract verification abi=[{copy paste the complete abi}]

``` * Web3 helper code is in web3helper.py

• Webserver code is in webserver.py

• Run the webserver ```sh python webserver.py

once the webserver is running access it using 127.0.0.1:8080 to check the status

```

Now transfer the token and eth using the below cURL api

```sh

Transfer eth change the address to desired target address and change the amount to desired amount

curl --header "Content-Type: application/json" --request POST --data '{"address":"0xE1d572356C174Baa4110A203a73cEEfEA4205180", "amount":"0.05"}' http://localhost:8080/eth

Transfer token change the address to desired target address

curl --header "Content-Type: application/json" --request POST --data '{"address":"0xE1d572356C174Baa4110A203a73cEEfEA4205180"}' http://localhost:8080/token ```

5 - Containerise the application using docker

for ease of running application over the webserver with out installing any dependencies or ther settings

Make sure to install docker engine and docker is running.

• Build the docker container using the Docerfile in this directory ```sh doceker build -t reponame/imagename

check the image is docker images

docker images * Run the docker continer sh

Create a direcory in the current directory (we will use this to mount the volume to the docker to make changes in the application later poin)\

mkdir dockervol

Run docker container using the image we created earlier

docker run --name custom_name -p 8090:8080 -d -v $(pwd)/dockervol:/var/dockervol reponame/imagename ```

Use the cURL api to so the transfer by replacing the http://localhost:8080/ethortoken to http://localhost:8090/ethortoken

• Push the new image to docker hub ```sh create a docker hub account

create a repository

name the repository with reponame/imagename

push the image to the created repo to from the terminal

docker login -u username

enter the password when propted

docker push reponame/imagename:latest * Pull the image from the docker hub sh docker pull reponame/imagename:latest ```

EOF