# Starter Script or User Data (NGINX as Reverse Proxy for Node.js with PM2) [Amazon Linux 2]

- Install Git
- Install Nginx
- Setup Nginx as a Reverse Proxy for your Node.js Application
- Install Node using NVM
- Install PM2
- Run a Dummy API Server Using express
- Start the Server using PM2
- Auto Start PM2 after a server reboot.

Login to Ec2 Instance - `ssh ec2-user@54.221.355.461 -i ~/.ssh/temp-personal.pem`

> This script is run by root user. But some part (`subscript`) of it is run as `ec2-user` so it can install `node.js` without sudo.

> Don't forget to allow HTTP Port 80 in your Security Group.

> The following script will completely overwrite your EC2 server's NGINX configuration to setup a reverse proxy.

> Don't forget to add a backslash **`\`** if you want to use **$** inside the `subscript`.

> You can check the output of this script `cat /var/log/cloud-init-output.log` or `cat /var/log/cloud-init.log`.


```sh
#!/bin/bash

cd /home/ec2-user/

## Updating Packages
sudo yum update -y

## Installing Git Client
sudo yum install git -y

## Installing Cronttab
sudo yum install crontabs -y
sudo chkconfig crond on
sudo service crond start

## Install Python
sudo yum install python3.x86_64 -y

## For system to be able to compile software, you need many development tools, such as make, gcc, and autoconf.
sudo yum groupinstall "Development Tools" -y

## Required By MongoDB
sudo yum install krb5-devel -y
sudo yum install cyrus-sasl cyrus-sasl-plain cyrus-sasl-gssapi krb5-libs libcurl libpcap net-snmp openldap openssl -y

## Installing Nginx
sudo amazon-linux-extras install nginx1.12 -y

## Modifying Nginx Server Configuration
sudo cat > /etc/nginx/nginx.conf <<EOL
user nginx;
worker_processes auto;
include /usr/share/nginx/modules/*.conf;
events {
    worker_connections 1024;
}
http {
    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 65;
    types_hash_max_size 2048;
    error_log /dev/null;
    access_log /dev/null;
    include /etc/nginx/mime.types;
    default_type application/octet-stream;
    upstream express_server {
        server 127.0.0.1:8080;
        keepalive 64;
    }
    server {
        listen 80 default_server;
        listen [::]:80 default_server;
        server_name _;
        location / {
            proxy_set_header X-Forwarded-For \$proxy_add_x_forwarded_for;
            proxy_set_header X-Real-IP \$remote_addr;
            proxy_set_header Host \$http_host;
            proxy_set_header Upgrade \$http_upgrade;
            proxy_set_header Connection "upgrade";
            proxy_http_version 1.1;
            proxy_pass http://express_server/;
            proxy_redirect off;
            proxy_read_timeout 240s;
        }
    }
}
EOL

## Starting Nginx Services
sudo chkconfig nginx on
sudo service nginx start
sudo service nginx restart

## Writing the Script to be run as ec2-user
cat > /tmp/subscript.sh << EOF

## Installing NVM
curl -sL https://raw.githubusercontent.com/nvm-sh/nvm/v0.34.0/install.sh | bash
 
echo 'export NVM_DIR="/home/ec2-user/.nvm"' >> /home/ec2-usr/.bashrc
echo '[ -s "\$NVM_DIR/nvm.sh" ] && . "\$NVM_DIR/nvm.sh"  # This loads nvm' >> /home/ec2-user/.bashrc
 
## Dot source the files to ensure that variables are available within the current shell
. /home/ec2-user/.nvm/nvm.sh
. /home/ec2-user/.bashrc
 
## Install Node.js
nvm install v10.16.3
nvm use v10.16.3
nvm alias default v10.16.3

## Installing Global PM2 package
npm install -g pm2

## Installing Yarn
curl -o- -L https://yarnpkg.com/install.sh | bash
export PATH="\$HOME/.yarn/bin:\$HOME/.config/yarn/global/node_modules/.bin:\$PATH"

## Creating API Directory
mkdir api
cd api

## You'd probably want to connect to your git repository here and
## pull the master branch, then build and run it.
## But we'll create a mini express server
yarn init -y
yarn add express

cat > ./app.js <<EOL
var express = require('express');
var app = express();
app.get('/', function(req, res){
   res.send("Hello World!");
});
app.listen(3001);
EOL

## Starting the Server
pm2 start app.js

## Saving the current state of pm2
pm2 save

## Adding Cron Job to Auto Restart PM2 on Reboot
cat <(crontab -l) <(echo "@reboot /home/ec2-user/.nvm/versions/node/v10.16.3/bin/node /home/ec2-user/.nvm/versions/node/v10.16.3/bin/pm2 resurrect") | crontab -

EOF

## Changing the owner of the temp script so ec2-user could run it 
chown ec2-user:ec2-user /tmp/subscript.sh && chmod a+x /tmp/subscript.sh

## Executing the script as ec2-user
sleep 1; su - ec2-user -c "/tmp/subscript.sh"
```