Introduction

This tool aims at listening the smart contracts of https://woken.exchange/
and push notifications in Discord channels on specific events on the smart contract

Prerequisite

You must have :

• node
• npm

installed on your host to run the app locally

Settings

Node dependencies

To install dependencies, just run the following command :

npm install

Addresses

Useful to do some tests and create LP pair

Goerli TestNet

WKN Token

0x841699991e4129BA98385f50CDc4235CdF4A9397

USDC

0xE06B56Fc1E19402E1a9DF3513E024a3b9847c9E5

Factory Address

0x1da474bE245f0C3bd1eE0F9F9f9B1CC353776b46

Factory Address (Test for roles)

0xd79128b22985fb7114D842b2BA419fb0794E36B1

Ways to listen smart contract events

Solution 1 : Websocket

In order to listen smart contract event, we can implements websocket.
This solution was chosen and it works on production.
The selected JS library to communicate with the blockchain is Alchemy-SDK based on the famous ethers.js library.

some steps are required to make work the bot that send notifications to the wanted Discord channel.

Step 1 : Alchemy Account

Create an account on Alchemy and create an app for the network you want to run the bot (Mainnet, TestNet)

After that, you can get your Alchemy key/auth token that will be used for websockets

Step 2 : Webhook in the discord channel

If you want to send notifications on a specific channel in Discord, you will have to create a Webhook on this channel.
To do that, you can refer to this video : https://www.youtube.com/watch?v=fKksxz2Gdnc
After that, you will have a signed URL (URL with secret token) which can be used to send notiifctations

Step 3 : Edit the .env file

Edit the .env file and fill the ALCHEMY_API_KEY key in this file You will need to fill other required keys like DISCORD_WEBHOOK_PROPOSAL_URL that is the URL provided by Discord when you created a Webhook on a channel.
The address of your factory smart contract is required as well. Fill it in FACTORY_ADDRESS key

Step 4 : Compile the project

npm run build

Step 4 : Run the project

npm run start:ws

You will see in the console these logs

meaning that your websockets arre listening these events and are ready to send notifications if needed !!

Solution 2 : Alchemy Notify Service

==> TODO later

Chosen Solution

We decided to choose the Websocket solution, so this discord notifier app will run with the following comand :

nm run start:ws

Deploy App on Amazon EC2

Remarks : Useful for the Solution 2 (Alchemy Notify Service) ==> Not used right now to listen smart contract !!

Step 1 : Create a free Ubuntu EC2 instance on AWS

Once created on AWS dashboard. Connect to it with SSH

Step 2 : Use 'root' user

sudo su

Step 3 : Install Curl

apt install curl

Step 4 : Install NVM

curl https://raw.githubusercontent.com/creationix/nvm/master/install.sh | bash

Then

source ~/.bashrc

Step 5 : Install Node using NVM

nvm install node

To install a specific version :

nvm install 18.16.0 

Step 6 : Install Git

apt update

then :

apt install git-all

Step 7 : Install PM2

npm install pm2 -g

Step 8 : Clone the repository

git clone https://github.com/gilbruno/Woken_Discord_Bot.git

Step 9 : Install node deps

npm install

Step 10 : Compile the app

npm run build

Step 11 : Create security rule to open HTTP for the right port

Do it in AWS EC2 in Security Groups ==> Open protocols and ports you need (SSH, TCP, TCP Custom, etc ...)

Step 12 : Create an Elastic IP and associate with your EC2 instance

This step is important to keep a fix IP and associate with a DNS ==> See AWS tuto for this

Step 13 : Install NGINX

This step is important to do a reverse proxy from NGINX to your NodeJS App As the port 80 is the port by default of Nginx, we do not need to specify a port in the URL So the URL without port will be able to be associated to tthe port 3000 of your app

apt install nginx

then launch the elastic IP in the URL without any port (80 by default)

Ex : http://13.49.112.85/

You must see this

If you see Apache. Apache is installed by default on your server. You must uninstall it and restart Nginx

Step 14 : Configure reverse Proxy

Edit the following file :

nano /etc/nginx/sites-available/default

In the location block, write this :

location / {
    proxy_pass http://localhost:3000; #whatever port your app runs on
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection 'upgrade';
    proxy_set_header Host $host;
    proxy_cache_bypass $http_upgrade;
}

On the root line, write the directory of your NodeJS app

root /home/ubuntu/woken/Woken_Discord_Bot;

Reload configuration :

nginx -t

Restart Nginx :

service nginx restart

Now you must see the home page of your NodeJS app when launching the elastic IP of your EC2 instance in browser !! And not the homepage of Nginx !

 Remarks

To connect to your EC2 with SSH :

ssh -i <path_to_your_pem_file_key> ec2-user@<IP_EC2_Instance>

Discord

Introduction

In this app, we only use a web hook to send notifications to a channel. But this app can be used to implements a Discord Bot.
To do this, some steps are required in the Discord developer portal.
Anyway, a little implementation of a Discord Bot than can be logged to a server was implemented in this app.
So, we an go further to implements more complexe features with a bot. Code is here !

Insctructions

Connect to the Discord Developer Portal on the URL : https://discord.com/developers.
If you have a Discord account, you will be connected with this account automatically.

Create an App

Use the left menu for that

Create a Bot

Use the left menu for that. The token will be used to login your bot to a server.

You must Grant all Privileged Gateway Intents :

• PRESENCE INTENT
• SERVER MEMBERS INTENT
• MESSAGE CONTENT INTENT

Add a bot to a server

In order to do that, you will run a endpoint (HTTP Request) to add your bot to the server you want. Even if you are not the administrator of the server.
So, you must generate the URL endpoint.
To do that, go to OAuth2 > URL Generator.
Then, in SCOPES block, select bot and in BOT PERMISSIONS BOT select Administrator.
After selecting these 2 values, the GENERATED URL appears in the bottom of the page.
Like below :

Ex : https://discord.com/api/oauth2/authorize?client_id=<My_Client_Id>&permissions=8&scope=bot

When execute this URL in a browser, the UI will suggest you all the server where you have admin role :

• on a server
• on at least one channel where you have admin roles or enough big roles.

If you choose a Discord server where you are an admin, you will get a notification to add/grant the new Bot on your server. If you choose a Discord server where you are an admin, the Discord server admn will be notified that someone wants to add a bot on his/her server. Once the bot added/granted in the server, you will be able to login your bot to this server.