Solution Project ECommerce Application

This guide shows how to build a safe, testable shell script to deploy the KodeKloud e-commerce application on CentOS (7/8). It documents the development approach — start with verified manual commands, then convert them into a small, well-structured script with checks, meaningful output, and idempotent operations. Follow the sequence: firewall → database → database population → web server → application clone & configuration → verification. Why this approach?

Verifying commands manually first avoids surprises when automating.
Small reusable functions make the script easier to test and maintain.
Basic runtime checks make failures easy to detect and debug.

Prerequisites

Requirement	Notes / Example
OS	CentOS 7 or 8 (local VM, cloud VM, or lab environment)
Privileges	An account with `sudo` or run the script as `root`
Network	Network access to install packages and clone the repository
Editor	Any editor (PyCharm, VS Code, Vim, nano)

Ports and components used

Component	Port / File	Purpose
FirewallD	`3306/tcp`, `80/tcp`	Open database & HTTP ports via `firewall-cmd`
MariaDB / MySQL	n/a	Database server for app data
Apache (httpd)	n/a	Serves PHP application
Repository	`https://github.com/kodekloudhub/learning-app-ecommerce.git`	Web app source to clone into `/var/www/html/`

Callout about privileges:

This script performs package installation and service configuration and uses sudo throughout. Run it from an account with sudo privileges or run the script as root.

Initial manual commands Start by copying and running these commands manually on a test VM to confirm behavior before automating:

# Install and configure FirewallD
sudo yum install -y firewalld
sudo service firewalld start
sudo systemctl enable firewalld

# Install and configure MariaDB
sudo yum install -y mariadb-server
sudo service mariadb start
sudo systemctl enable mariadb

# Open MariaDB port in firewall
sudo firewall-cmd --permanent --zone=public --add-port=3306/tcp
sudo firewall-cmd --reload

Development approach (recommended)

Build a minimal working script by grouping the verified manual commands.
Test each logical block in a disposable/test VM to ensure it runs non-interactively.
Improve iteratively:
- Add comments and colored, informative output.
- Add service and firewall checks.
- Verify DB contents and web page content.
- Keep functions small and reusable.
Use safe file modifications (for example, sed with backups) if you need to edit config files.

Database configuration best practices

Use a separate SQL file for creation of DB/users (configure-db.sql) and another for loading data (db-load-script.sql).
Invoke these files non-interactively: sudo mysql < configure-db.sql and sudo mysql < db-load-script.sql.
This guide uses sudo mysql so no password is required (root login). If production uses authentication, parameterize credentials and secure them properly.

Sample SQL used by the script — configure-db.sql

CREATE DATABASE ecomdb;
CREATE USER 'ecomuser'@'localhost' IDENTIFIED BY 'ecompassword';
GRANT ALL PRIVILEGES ON *.* TO 'ecomuser'@'localhost';
FLUSH PRIVILEGES;

— db-load-script.sql

USE ecomdb;
CREATE TABLE products (
  id mediumint(8) unsigned NOT NULL auto_increment,
  Name varchar(255) default NULL,
  Price varchar(255) default NULL,
  ImageUrl varchar(255) default NULL,
  PRIMARY KEY (id)
) AUTO_INCREMENT=1;

INSERT INTO products (Name,Price,ImageUrl) VALUES
  ("Laptop","100","c-1.png"),
  ("Drone","200","c-2.png"),
  ("VR","300","c-3.png"),
  ("Tablet","50","c-5.png"),
  ("Watch","90","c-6.png"),
  ("Phone Covers","20","c-7.png"),
  ("Phone","80","c-8.png"),
  ("Laptop","150","c-4.png");

Web server configuration notes

Install Apache (httpd), PHP, and the PHP MySQL extension (php-mysql on CentOS).
Open port 80 in FirewallD.
Configure Apache to prefer index.php over index.html:
- sudo sed -i 's/index.html/index.php/g' /etc/httpd/conf/httpd.conf
Clone the web app into /var/www/html/ and replace hard-coded database IPs with localhost in index.php.

A polished, production-aware script Below is a consolidated, improved script that demonstrates:

Shebang and header comments.
Reusable functions for colored output, service checks, firewall checks, DB verification, and content checks.
Clear sequence: firewall → MariaDB → DB creation & load → web server → app clone & config → verification.

Save this as deploy-ecommerce-application.sh, make it executable, and run it in a test VM: chmod +x deploy-ecommerce-application.sh && sudo ./deploy-ecommerce-application.sh

#!/bin/bash
#
# deploy-ecommerce-application.sh
# Automates deployment of the KodeKloud e-commerce application on CentOS.
# Tested on CentOS 7.x virtual machines.
#
set -euo pipefail

###############################
# Print a message in color
# Arguments:
#   $1 - color name (green|red|yellow|nc)
#   $2 - message
###############################
function print_color() {
  local COLOR NC
  NC='\033[0m'
  case "$1" in
    green) COLOR='\033[0;32m' ;;
    red) COLOR='\033[0;31m' ;;
    yellow) COLOR='\033[0;33m' ;;
    nc|*) COLOR="${NC}" ;;
  esac
  echo -e "${COLOR}$2${NC}"
}

###############################
# Check that a systemd service is active
# Arguments:
#   $1 - service name
# Exits with non-zero status if not active.
###############################
function check_service_status() {
  local svc="$1"
  local state
  state=$(systemctl is-active "$svc" 2>/dev/null || echo "unknown")
  if [ "$state" = "active" ]; then
    print_color green "$svc service is active"
  else
    print_color red "$svc service is not active (state: $state)"
    exit 1
  fi
}

###############################
# Check if a firewall port is configured in the public zone (firewalld)
# Arguments:
#   $1 - port number (e.g., 3306 or 80)
# Exits with non-zero status if not configured.
###############################
function check_firewalld_port() {
  local port="$1"
  local ports
  ports=$(sudo firewall-cmd --zone=public --list-ports --permanent || echo "")
  if [[ $ports == *"${port}/tcp"* ]]; then
    print_color green "Firewalld: port ${port}/tcp is configured"
  else
    print_color red "Firewalld: port ${port}/tcp is NOT configured"
    exit 1
  fi
}

###############################
# Check if the database has rows in products table
# Exits with non-zero status if the table is missing or empty.
###############################
function check_db_loaded() {
  local count
  count=$(sudo mysql -e "USE ecomdb; SELECT COUNT(*) FROM products;" 2>/dev/null | awk 'NR==2{print $1}' || echo "0")
  if [[ "$count" =~ ^[0-9]+$ ]] && [ "$count" -gt 0 ]; then
    print_color green "Inventory data loaded into database (products count: $count)"
  else
    print_color red "Inventory data not loaded into database"
    exit 1
  fi
}

###############################
# Check if an item string is present in a web page
# Arguments:
#   $1 - URL or page content (pass content in quotes)
#   $2 - Item string to search
###############################
function check_item() {
  local page_content="$1"
  local item="$2"
  if [[ $page_content == *"$item"* ]]; then
    print_color green "Item '$item' is present on the web page"
  else
    print_color red "Item '$item' is NOT present on the web page"
  fi
}

# ---------------- Database Configuration ----------------
print_color green "Installing and configuring FirewallD..."
sudo yum install -y firewalld
sudo systemctl enable --now firewalld
check_service_status firewalld

print_color green "Installing MariaDB (mariadb-server)..."
sudo yum install -y mariadb-server
sudo systemctl enable --now mariadb
check_service_status mariadb

print_color green "Opening MariaDB port in FirewallD (3306)..."
sudo firewall-cmd --permanent --zone=public --add-port=3306/tcp
sudo firewall-cmd --reload
check_firewalld_port 3306

print_color green "Configuring database and user..."
cat > configure-db.sql <<-EOF
CREATE DATABASE IF NOT EXISTS ecomdb;
CREATE USER IF NOT EXISTS 'ecomuser'@'localhost' IDENTIFIED BY 'ecompassword';
GRANT ALL PRIVILEGES ON *.* TO 'ecomuser'@'localhost';
FLUSH PRIVILEGES;
EOF

sudo mysql < configure-db.sql
print_color green "Database configuration applied."

print_color green "Loading inventory data into database..."
cat > db-load-script.sql <<-EOF
USE ecomdb;
CREATE TABLE IF NOT EXISTS products (
  id mediumint(8) unsigned NOT NULL auto_increment,
  Name varchar(255) default NULL,
  Price varchar(255) default NULL,
  ImageUrl varchar(255) default NULL,
  PRIMARY KEY (id)
) AUTO_INCREMENT=1;

INSERT INTO products (Name,Price,ImageUrl) VALUES
  ("Laptop","100","c-1.png"),
  ("Drone","200","c-2.png"),
  ("VR","300","c-3.png"),
  ("Tablet","50","c-5.png"),
  ("Watch","90","c-6.png"),
  ("Phone Covers","20","c-7.png"),
  ("Phone","80","c-8.png"),
  ("Laptop","150","c-4.png");
EOF

sudo mysql < db-load-script.sql
check_db_loaded

print_color green "---------------- Setup Database Server - Finished ----------------"

# ---------------- Web Server Configuration ----------------
print_color green "Installing Apache (httpd), PHP and dependencies..."
sudo yum install -y httpd php php-mysql
print_color green "Opening HTTP port in FirewallD (80)..."
sudo firewall-cmd --permanent --zone=public --add-port=80/tcp
sudo firewall-cmd --reload
check_firewalld_port 80

print_color green "Configuring Apache to prefer index.php..."
sudo sed -i 's/index.html/index.php/g' /etc/httpd/conf/httpd.conf

print_color green "Starting and enabling httpd..."
sudo systemctl enable --now httpd
check_service_status httpd

print_color green "Installing git and cloning web application repository..."
sudo yum install -y git
# Clone into /var/www/html/; use sudo because permissions may require it
sudo rm -rf /var/www/html/*        # ensure a clean directory (careful!)
sudo git clone https://github.com/kodekloudhub/learning-app-ecommerce.git /var/www/html/

print_color green "Replacing hard-coded DB IP with localhost in index.php..."
sudo sed -i 's/172.20.1.101/localhost/g' /var/www/html/index.php

print_color green "All set. Verifying web application content..."

# Verify web application content
web_page=$(curl -s http://localhost || true)

# Check presence of common items using a loop
for item in "Laptop" "Drone" "VR" "Phone"; do
  check_item "$web_page" "$item"
done

print_color green "Deployment finished successfully."

Verification checklist

Services active: firewalld, mariadb, httpd
Firewall ports permanent: 3306/tcp, 80/tcp
Database exists and products table populated (script checks count)
App files present in /var/www/html/
Web page contains expected item names (script checks with curl)

Testing and teardown suggestions

Revert VM snapshots between runs for quick testing.
Alternatively, create a teardown script to:
- stop services: sudo systemctl stop httpd mariadb firewalld
- remove installed packages (e.g., sudo yum remove -y httpd mariadb-server git php)
- remove app files: sudo rm -rf /var/www/html/*
- restore changed config files from backups you create before editing them
If using an ephemeral test environment, snapshots are simpler and safer.

Additional improvements to consider

Add a log file for stdout/stderr (redirect to /var/log/deploy-ecommerce.log).
Add retries for transient failures (yum repos, network timeouts).
Parameterize script variables: DB name, user, password, repo URL, and target directory.
Use a configuration management tool (Ansible, Puppet, Chef) for production deployments and drift management.
Secure credentials with a vault or environment variables rather than embedding sensitive values.

Links and references

Tip: Keep scripts modular (small reusable functions) and add clear messages and checks so failures are visible and easy to debug.

Course Introduction

Flow Control

Shebang

Project - E-Commerce Application

Conclusion

Shell Script Introduction

Solution Project ECommerce Application

Watch Video