Backend

    - Allowed ec2 instance public IP on mongodb server
    - npm install pm-2 -g
    - pm2 start npm --name "codershub-backend" -- start
    - pm2 logs
    - pm2 list, pm2 flush  <name>, pm2 stop <name>, pm2 delete <name>
    - config nginx - /etc/nginx/sites-available/default
    - restart nginx - sudo systemctl restart nginx
    - Modify the BASEURL in frontned project to "/api"


Frontend = http://16.16.76.83/
Backend = http://16.16.76.83:3000/

Domain name = codershub.com

Frontend = codershub.com
Backend = codershub.com:3000/ => codershub.com/api (proxy pass)

nginx config:

server_name 16.16.76.83;

location /api/ {
             proxy_pass http://localhost:3000/;
             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;
        }

Adding a custom Domain name

    - purchased domain name from godaddy
    - signup on cludflare & add a new domain name
    - change the nameservers on godaddy and point it to cloudflare
    - wait for sometimes till your nameservers are updated
    - DNS record: A joincodershub.com
    - Enable SSL for website [Full (strict)]

Sending Emails via SES

    - Create a IAM user
    - Give Access to AmazonSESFullAccess
    - Amazon SES: Create an Identity
    - Verify Your domain name
    - Verify an email address identity
    - Install AWS SDK - v3
    - code Example https://github.com/awsdocs/aws-doc-sdk-examples/blob/main/javascriptv3/example_code/ses/src/ses_sendemail.js
    - Setup SesClient
    - Access Credentials should be created in IAm under SecurityCredentials Tab
    - Add the credentials to the .env file

Scheduling cron jobs in NOdeJs

    - Installing node-cron
    - Learning about cron expressions syntax - crontab.guru
    - Schedule a job
    - date-fns
    - find all the unique email Id who have got connection Request in previous day
    - send Email
    - we can explore queue mechanism to send bulk emails
    - Another option is Amazon SES Bulk Emails
    - Two NPM packages : bee-queue & bull

Razorpay Payment Gateway Integration

    - Sign Up on Razorpay and complete KYC
    - Created a UI for premium page
    - Creating an API for create order in backend
    - Added key and secrets in env file
    - Initialized Razorpay in utils
    - Creating order on razorpay
    - create schema and model
    - saved the order in payment collection
    - make the API dynamic
    - setup Razorpay webhook on live API

Real Time Chat using websocket(Socket.io)

    - Build the UI for chat window on /chat/:targetUserId
    - setup socket.io in Backend => npm i socket.io
    - import http from "http"
    - created a server
    - import Server from socket.io
    - cors configuaration on server 
    - start listening to connections => io.on("connection", (socket) => {Handle Events})
    - setup socket.io in the Frontend => npm i socket.io-client
    - Inside socket.js =>  import io from socket.io-client
    - connect the socket with backend 
    - Inside Chat.js => as soon as page loaded, the socket connections is made  joinChat evet is emitted
    - As page unloads or unmounts dissconnect the socket