Skip to content

07-Automating-Load-Balancer-Configuration-with-Shell-Scripting

Directory actions

More options

Directory actions

More options

Latest commit

 

History

History

07-Automating-Load-Balancer-Configuration-with-Shell-Scripting

Folders and files

NameName
Last commit message
Last commit date

parent directory

..
images
images
 
 
README.md
README.md
 
 

README.md

Automating Load Balancer Configuration With Shell Scripting

The following steps are taken to automate a Load Balancer configuration to distribute traffic between 2 Web Servers with shell scripting:

Step 1: Provision an EC2 Instance for the 1st Web Server

Use the following parameters when configuring the EC2 Instance:

  • Name of Instance: Web Server 1
  • AMI: Ubuntu Server 22.04 LTS (HVM), SSD Volume Type
  • New Key Pair Name: web11
  • Key Pair Type: RSA
  • Private Key File Format: .pem
  • New Security Group: Apache Web Server Security Group
  • Inbound Rules: Allow Traffic From Anywhere On Port 8000 and Port 22.

web server 1 Instance Summary for Web Server 1

Step 2: Connect to the 1st Web Server via the terminal using SSH

  • Open the terminal on your computer.
  • Run the following command to go to the directory (i.e. Downloads) where the .pem key pair file was downloaded.
cd Downloads
  • Paste the following command to give read permissions to the .pem key pair file:
sudo chmod 400 <private-key-pair-name>.pem

chmod key pair

  • SSH into the Web Server 1 Instance using the command shown below:
ssh -i <private-key-name>.pem ubuntu@<Public-IP-address>

ssh web server 1

Step 3: Deployment of the 1st Web Server

  • Create and open a file install.sh using the command shown below:
sudo vi install.sh
  • Paste the script shown below into the file then save and exit the file:
#!/bin/bash

####################################################################################################################
##### This automates the installation and configuring of apache webserver to listen on port 8000
##### Usage: Call the script and pass in the Public_IP of your EC2 instance as the first argument as shown below:
######## ./install_configure_apache.sh 18.234.230.94
####################################################################################################################

set -x # debug mode
set -e # exit the script if there is an error
set -o pipefail # exit the script when there is a pipe failure

PUBLIC_IP=18.234.230.94

[ -z "${PUBLIC_IP}" ] && echo "Please pass the public IP of your EC2 instance as an argument to the script" && exit 1

sudo apt update -y &&  sudo apt install apache2 -y

sudo systemctl status apache2

if [[ $? -eq 0 ]]; then
    sudo chmod 777 /etc/apache2/ports.conf
    echo "Listen 8000" >> /etc/apache2/ports.conf
    sudo chmod 777 -R /etc/apache2/

    sudo sed -i 's/<VirtualHost \*:80>/<VirtualHost *:8000>/' /etc/apache2/sites-available/000-default.conf

fi
sudo chmod 777 -R /var/www/
echo "<!DOCTYPE html>
        <html>
        <head>
            <title>My EC2 Instance</title>
        </head>
        <body>
            <h1>Welcome to my 1st Web Server EC2 instance</h1>
            <p>Public IP: "${PUBLIC_IP}"</p>
        </body>
        </html>" > /var/www/html/index.html

sudo systemctl restart apache2

web server 1 script

  • Assign executable permissions on the file using the command shown below:
sudo chmod +x install.sh

sudo chmod install.sh

  • Run the shell script using the command shown below:
./install.sh

run web server 1 script

  • Go to your web browser and paste the following URL to verify the setup:
http://public_ip_address_of_web_server_1:8000

http public ip web server 1

Step 4: Provision an EC2 Instance for the 2nd Web Server

Use the following parameters when configuring the EC2 Instance:

  • Name of Instance: Web Server 2
  • AMI: Ubuntu Server 22.04 LTS (HVM), SSD Volume Type
  • Key Pair Name: web11
  • Security Group: Apache Server Security Group

web server 2

Instance Summary for Web Server 2

Step 5: Connect to the 2nd Web Server via the terminal using SSH

  • Open the terminal on your computer.
  • Run the following command to go to the directory (i.e. Downloads) where the .pem key pair file was downloaded.
cd Downloads
  • SSH into the Web Server 2 Instance using the command shown below:
ssh -i <private-key-name>.pem ubuntu@<Public-IP-address>

ssh web server 2

Step 6: Deployment of the 2nd Web Server

  • Create and open a file install.sh using the command shown below:
sudo vi install.sh
  • Paste the script shown below into the file then save and exit the file:
#!/bin/bash

####################################################################################################################
##### This automates the installation and configuring of apache webserver to listen on port 8000
##### Usage: Call the script and pass in the Public_IP of your EC2 instance as the first argument as shown below:
######## ./install_configure_apache.sh 18.234.230.94
####################################################################################################################

set -x # debug mode
set -e # exit the script if there is an error
set -o pipefail # exit the script when there is a pipe failure

PUBLIC_IP=54.175.35.61

[ -z "${PUBLIC_IP}" ] && echo "Please pass the public IP of your EC2 instance as an argument to the script" && exit 1

sudo apt update -y &&  sudo apt install apache2 -y

sudo systemctl status apache2

if [[ $? -eq 0 ]]; then
    sudo chmod 777 /etc/apache2/ports.conf
    echo "Listen 8000" >> /etc/apache2/ports.conf
    sudo chmod 777 -R /etc/apache2/

    sudo sed -i 's/<VirtualHost \*:80>/<VirtualHost *:8000>/' /etc/apache2/sites-available/000-default.conf

fi
sudo chmod 777 -R /var/www/
echo "<!DOCTYPE html>
        <html>
        <head>
            <title>My EC2 Instance</title>
        </head>
        <body>
            <h1>Welcome to my 2nd Web Server EC2 instance</h1>
            <p>Public IP: "${PUBLIC_IP}"</p>
        </body>
        </html>" > /var/www/html/index.html

sudo systemctl restart apache2

web server 2 script

  • Assign executable permissions on the file using the command shown below:
sudo chmod +x install.sh

chmod install.sh

  • Run the shell script using the command shown below:
./install.sh

run web server 2 script

  • Go to your web browser and paste the following URL to verify the setup:
http://public_ip_address_of_web_server_2:8000

http web server 2

Step 8: Provision an EC2 Instance for the Load Balancer

Use the following parameters when configuring the EC2 Instance:

  • Name of Instance: Load Balancer
  • AMI: Ubuntu Server 22.04 LTS (HVM), SSD Volume Type
  • New Key Pair Name: web11
  • New Security Group With Inbound Rules: Allow Traffic From Anywhere On Port 80 and Port 22.

load balancer

Instance Summary for Load Balancer

Step 9: Connect to the Load Balancer via the terminal using SSH

  • Open the terminal on your computer.
  • Run the following command to go to the directory (i.e. Downloads) where the .pem key pair file was downloaded.
cd Downloads
  • SSH into the Load Balancer Instance using the command shown below:
ssh -i <private-key-name>.pem ubuntu@<Public-IP-address>

ssh load balancer

Step 10: Deploying and Configuring Nginx Load Balancer

  • Create and open a file nginx.sh using the command shown below:
sudo vi nginx.sh
  • Paste the script shown below into the file then save and exit the file:
#!/bin/bash

######################################################################################################################
##### This automates the configuration of Nginx to act as a load balancer
##### Usage: The script is called with 3 command line arguments. The public IP of the EC2 instance where Nginx is installed
##### the webserver urls for which the load balancer distributes traffic. An example of how to call the script is shown below:
##### ./configure_nginx_loadbalancer.sh PUBLIC_IP Webserver-1 Webserver-2
#####  ./configure_nginx_loadbalancer.sh 54.90.83.129 18.234.230.94:8000 54.175.35.61:8000
############################################################################################################# 

PUBLIC_IP=54.90.83.129
firstWebserver=18.234.230.94:8000
secondWebserver=54.175.35.61:8000

[ -z "${PUBLIC_IP}" ] && echo "Please pass the Public IP of your EC2 instance as the argument to the script" && exit 1

[ -z "${firstWebserver}" ] && echo "Please pass the Public IP together with its port number in this format: 127.0.0.1:8000 as the second argument to the script" && exit 1

[ -z "${secondWebserver}" ] && echo "Please pass the Public IP together with its port number in this format: 127.0.0.1:8000 as the third argument to the script" && exit 1

set -x # debug mode
set -e # exit the script if there is an error
set -o pipefail # exit the script when there is a pipe failure


sudo apt update -y && sudo apt install nginx -y
sudo systemctl status nginx

if [[ $? -eq 0 ]]; then
    sudo touch /etc/nginx/conf.d/loadbalancer.conf

    sudo chmod 777 /etc/nginx/conf.d/loadbalancer.conf
    sudo chmod 777 -R /etc/nginx/

    
    echo " upstream backend_servers {

            # your are to replace the public IP and Port to that of your webservers
            server  "${firstWebserver}"; # public IP and port for webserver 1
            server "${secondWebserver}"; # public IP and port for webserver 2

            }

           server {
            listen 80;
            server_name "${PUBLIC_IP}";

            location / {
                proxy_pass http://backend_servers;   
            }
    } " > /etc/nginx/conf.d/loadbalancer.conf
fi

sudo nginx -t

sudo systemctl restart nginx

load balancer script

  • Assign executable permissions on the file using the command shown below:
sudo chmod +x nginx.sh

chmod nginx.sh

  • Run the shell script using the command shown below:
./nginx.sh

run load balncer script

  • Go to your web browser and paste the following URL to verify the setup:
http://public_ip_address_of_load_balancer:80

http ip load balancer1

http ip load balancer2

Each time you refresh the page, you will see the web page of Web Server 1 and Web Server 2 as shown above.