How To Install CodeIgniter on Linux Mint 22

Installing CodeIgniter on Linux Mint 22 opens the door to rapid PHP web development with one of the most popular and lightweight frameworks available today. This comprehensive guide walks you through every step of the installation process, from system preparation to running your first CodeIgniter application.

CodeIgniter stands out as an exceptional PHP framework due to its minimal footprint, clear documentation, and gentle learning curve. The framework follows the Model-View-Controller (MVC) architectural pattern, which promotes organized code structure and maintainability. With its small download size of less than 3MB and straightforward configuration, CodeIgniter enables developers to build robust web applications quickly without the complexity often associated with other frameworks.

Linux Mint 22, based on Ubuntu’s long-term support release, provides an ideal environment for web development. Its stability, user-friendly interface, and excellent package management system make it perfect for both beginners and experienced developers. The operating system comes with essential development tools pre-installed and offers seamless compatibility with PHP frameworks like CodeIgniter.

This tutorial targets developers ranging from beginners to intermediate levels who want to set up a professional CodeIgniter development environment. By following these instructions, you’ll have a fully functional CodeIgniter installation ready for building dynamic web applications within 30-45 minutes.

Table of Contents

System Requirements and Prerequisites

PHP Environment Setup

CodeIgniter 4 requires PHP 7.2 or newer, though PHP 8.1+ is strongly recommended for optimal performance and security. The framework demands several PHP extensions for full functionality:

Essential PHP Extensions:

intl: Provides internationalization support for multi-language applications
mbstring: Handles multibyte string operations for Unicode compatibility
json: Processes JSON data structures used throughout modern web development
mysqlnd or mysqli: Enables database connectivity with MySQL/MariaDB

Recommended PHP Extensions:

curl: Facilitates HTTP client functionality for external API integrations
xml: Processes XML documents and enables SOAP web services
zip: Handles archive operations for file compression and extraction
gd or ImageMagick: Provides image manipulation capabilities for dynamic graphics

Web Server Configuration

Apache HTTP Server 2.4+ serves as the primary web server choice due to its robust feature set and extensive documentation. The server requires mod_rewrite enabled for clean URL functionality. Alternative options include Nginx for high-performance scenarios, LiteSpeed for commercial applications, or PHP’s built-in development server for local testing.

Key Apache requirements include virtual host support for multiple projects and .htaccess file processing for URL rewriting rules. These features enable CodeIgniter’s routing system to function correctly and provide the clean URLs that modern web applications demand.

Database Server Requirements

CodeIgniter supports multiple database systems including MySQL 5.1+, MariaDB, PostgreSQL, SQLite, and Microsoft SQL Server. For Linux Mint 22 installations, MySQL 8.0+ or MariaDB 10.4+ offer the best compatibility and performance. The chosen database system must have appropriate PDO drivers installed to ensure seamless connectivity.

System Prerequisites Checklist

Before beginning the installation process, verify these system requirements:

Operating System: Linux Mint 22 with recent updates installed
User Privileges: Root access or sudo privileges for software installation
Internet Connection: Active connection for downloading packages and dependencies
Disk Space: Minimum 500MB free space for complete installation with room for development
Memory: At least 1GB RAM for comfortable development environment performance

Preparing the Linux Mint 22 Environment

System Updates and Package Management

Start by updating your Linux Mint 22 system to ensure all packages are current and security patches are applied:

sudo apt update
sudo apt upgrade -y

The first command refreshes the package repository information, while the second upgrades all installed packages to their latest versions. Install essential build tools and utilities needed for web development:

sudo apt install curl wget unzip git software-properties-common

These tools provide file downloading capabilities, archive extraction, version control, and repository management functions essential for modern PHP development workflows.

Apache Web Server Installation and Configuration

Install Apache HTTP Server using the package manager:

sudo apt install apache2

Configure Apache service management to ensure automatic startup:

sudo systemctl start apache2
sudo systemctl enable apache2
sudo systemctl status apache2

The status command should display “active (running)” indicating successful installation. Configure the firewall to allow HTTP and HTTPS traffic:

sudo ufw allow 'Apache Full'

Test the Apache installation by opening a web browser and navigating to http://localhost. You should see the Apache2 Ubuntu Default Page confirming successful installation.

Key Apache directories to remember:

Document root: /var/www/html/
Configuration files: /etc/apache2/
Available sites: /etc/apache2/sites-available/
Enabled sites: /etc/apache2/sites-enabled/
Log files: /var/log/apache2/

PHP Installation and Essential Extensions

Install PHP along with the Apache module and essential extensions:

sudo apt install php libapache2-mod-php php-cli php-common php-mbstring php-xml php-zip php-curl php-mysql php-intl php-json php-gd

This comprehensive installation includes all necessary components for CodeIgniter development. Verify the PHP installation and version:

php -v

Edit the PHP configuration file to optimize settings for web development:

sudo nano /etc/php/8.3/apache2/php.ini

Critical PHP configuration adjustments:

memory_limit = 256M – Increases available memory for PHP processes
upload_max_filesize = 64M – Allows larger file uploads
post_max_size = 64M – Increases POST request size limits
max_execution_time = 300 – Extends script execution time for development

After making changes, restart Apache to apply the new configuration:

sudo systemctl restart apache2

Database Server Setup and Security

Install MariaDB server, which offers better performance and compatibility with Linux Mint:

sudo apt install mariadb-server mariadb-client

Alternatively, install MySQL if preferred:

sudo apt install mysql-server mysql-client

Start and enable the database service:

sudo systemctl start mariadb
sudo systemctl enable mariadb

Run the security installation script to configure initial database security:

sudo mysql_secure_installation

This interactive script prompts for several security configurations:

Set root password (create a strong password)
Remove anonymous users (recommended: Yes)
Disallow root login remotely (recommended: Yes)
Remove test database (recommended: Yes)
Reload privilege tables (recommended: Yes)

Apache Module Configuration

Enable essential Apache modules for CodeIgniter functionality:

sudo a2enmod rewrite
sudo a2enmod ssl
sudo a2enmod headers

The rewrite module enables clean URLs, SSL provides HTTPS support, and headers allows custom HTTP header manipulation. Restart Apache to activate these modules:

sudo systemctl restart apache2

Verify enabled modules:

apache2ctl -M | grep -E "(rewrite|ssl|headers)"

Installing Composer for Dependency Management

Understanding Composer’s Role

Composer serves as PHP’s de facto dependency manager, revolutionizing how developers handle third-party packages and autoloading. For CodeIgniter installations, Composer manages framework updates, installs additional packages, and provides PSR-4 autoloading capabilities that modern PHP development demands.

Composer Installation Process

Download and install Composer using the official installer script:

curl -sS https://getcomposer.org/installer | php

This command downloads the Composer installer and executes it using PHP. Move the generated composer.phar file to a global location:

sudo mv composer.phar /usr/local/bin/composer
sudo chmod +x /usr/local/bin/composer

Verify the installation:

composer --version

The output should display Composer version information, confirming successful installation.

Alternative Installation Method

Linux Mint users can alternatively install Composer through the package manager:

sudo apt install composer

However, this method may provide an older version. The manual installation ensures you have the latest Composer release with all current features and security updates.

Composer Configuration and Optimization

Configure Composer for optimal performance:

composer config --global process-timeout 2000
composer config --global cache-ttl 86400

These settings increase the process timeout for large installations and optimize cache behavior for better performance during subsequent package installations.

Installing CodeIgniter Using Composer

Project Directory Preparation

Navigate to the web server’s document root:

cd /var/www/html

For development purposes, you might prefer installing in your home directory:

cd ~/development
mkdir codeigniter-projects
cd codeigniter-projects

CodeIgniter Installation Command

Create a new CodeIgniter project using Composer’s create-project command:

composer create-project codeigniter4/appstarter my-codeigniter-app

Replace “my-codeigniter-app” with your preferred project name. This command downloads CodeIgniter 4 and all dependencies, creating a complete project structure ready for development.

For specific version installation:

composer create-project codeigniter4/appstarter:4.3.* my-codeigniter-app

The installation process typically takes 2-5 minutes depending on internet connection speed and system performance.

Project Structure Analysis

After installation, examine the created directory structure:

my-codeigniter-app/
├── app/                    # Application logic (controllers, models, views)
├── public/                 # Web-accessible directory (document root)
├── system/                 # CodeIgniter core files
├── vendor/                 # Composer dependencies
├── writable/              # Cache, logs, uploads
├── .env                   # Environment configuration
├── composer.json          # Dependency configuration
└── spark                  # CLI tool

Key directories explained:

app/: Contains your application code including controllers, models, views, and configuration
public/: Serves as the web server document root containing index.php and assets
system/: Houses CodeIgniter core framework files (rarely modified)
vendor/: Stores Composer-managed dependencies and autoloader
writable/: Provides storage for cache files, logs, and file uploads

File Permissions Configuration

Set appropriate file permissions for web server access:

cd my-codeigniter-app
sudo chown -R www-data:www-data .
sudo chmod -R 755 .
sudo chmod -R 777 writable/

For development environments, more permissive settings work better:

chmod -R 755 .
chmod -R 777 writable/
chmod -R 777 public/uploads/  # If you plan to handle file uploads

Environment Configuration Setup

Copy the environment template and configure it:

cp env .env
nano .env

Essential environment settings:

CI_ENVIRONMENT = development
app.baseURL = 'http://localhost/my-codeigniter-app/public/'

database.default.hostname = localhost
database.default.database = codeigniter_db
database.default.username = ci_user
database.default.password = your_secure_password

The environment file keeps sensitive configuration data separate from your codebase, enabling different settings for development, testing, and production environments.

Configuring Apache Virtual Host for CodeIgniter

Creating Virtual Host Configuration

Create a new Apache virtual host configuration file:

sudo nano /etc/apache2/sites-available/codeigniter.conf

Add the following virtual host configuration:

<VirtualHost *:80>
    ServerName codeigniter.local
    ServerAlias www.codeigniter.local
    DocumentRoot /var/www/html/my-codeigniter-app/public
    
    <Directory /var/www/html/my-codeigniter-app/public>
        AllowOverride All
        Require all granted
        DirectoryIndex index.php
    </Directory>
    
    <Directory /var/www/html/my-codeigniter-app>
        AllowOverride All
        Require all granted
    </Directory>
    
    ErrorLog ${APACHE_LOG_DIR}/codeigniter_error.log
    CustomLog ${APACHE_LOG_DIR}/codeigniter_access.log combined
</VirtualHost>

Configuration breakdown:

ServerName: Sets the primary domain name for the virtual host
DocumentRoot: Points to CodeIgniter’s public directory (crucial for security)
AllowOverride All: Enables .htaccess file processing for URL rewriting
DirectoryIndex: Specifies index.php as the default file
Error/Access logs: Separate log files for easier debugging

Activating the Virtual Host

Enable the new site configuration:

sudo a2ensite codeigniter.conf

Optionally disable the default Apache site to avoid conflicts:

sudo a2dissite 000-default.conf

Test the Apache configuration for syntax errors:

sudo apache2ctl configtest

If the test returns “Syntax OK,” reload Apache to apply changes:

sudo systemctl reload apache2

Local Domain Configuration

Add the local domain to your hosts file:

sudo nano /etc/hosts

Add this line:

127.0.0.1    codeigniter.local www.codeigniter.local

This configuration allows you to access your CodeIgniter application using a friendly domain name instead of localhost paths.

SSL Configuration for Development (Optional)

For HTTPS development, create a self-signed certificate:

sudo openssl req -x509 -nodes -days 365 -newkey rsa:2048 \
    -keyout /etc/ssl/private/codeigniter.key \
    -out /etc/ssl/certs/codeigniter.crt

Create an SSL virtual host configuration:

<VirtualHost *:443>
    ServerName codeigniter.local
    DocumentRoot /var/www/html/my-codeigniter-app/public
    
    SSLEngine on
    SSLCertificateFile /etc/ssl/certs/codeigniter.crt
    SSLCertificateKeyFile /etc/ssl/private/codeigniter.key
    
    <Directory /var/www/html/my-codeigniter-app/public>
        AllowOverride All
        Require all granted
    </Directory>
</VirtualHost>

Database Setup and Configuration

Creating the Database

Access the MariaDB/MySQL console:

sudo mysql -u root -p

Create a new database for your CodeIgniter application:

CREATE DATABASE codeigniter_db CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

The UTF8MB4 character set provides full Unicode support including emoji and special characters commonly used in modern web applications.

Database User Management

Create a dedicated database user for enhanced security:

CREATE USER 'ci_user'@'localhost' IDENTIFIED BY 'your_secure_password_here';
GRANT ALL PRIVILEGES ON codeigniter_db.* TO 'ci_user'@'localhost';
FLUSH PRIVILEGES;

Test the new user connection:

mysql -u ci_user -p codeigniter_db

CodeIgniter Database Configuration

Update the database configuration in your .env file:

database.default.hostname = localhost
database.default.database = codeigniter_db
database.default.username = ci_user
database.default.password = your_secure_password_here
database.default.DBDriver = MySQLi
database.default.DBPrefix = 
database.default.port = 3306

For production environments, consider using environment-specific configuration files to keep sensitive data secure.

Testing Database Connectivity

Create a simple test to verify database connectivity. Add this temporary route to app/Config/Routes.php:

$routes->get('/dbtest', function() {
    $db = \Config\Database::connect();
    if ($db->connID) {
        return "Database connection successful!";
    } else {
        return "Database connection failed!";
    }
});

Running and Testing Your CodeIgniter Application

Using the Built-in Development Server

CodeIgniter includes a built-in development server perfect for local testing:

cd /var/www/html/my-codeigniter-app
php spark serve

Access your application at http://localhost:8080. For custom port assignment:

php spark serve --port=8081 --host=0.0.0.0

The --host=0.0.0.0 option allows network access, useful for testing on multiple devices.

Apache Virtual Host Testing

If you configured a virtual host, access your application using:

http://codeigniter.local

You should see the CodeIgniter welcome page displaying version information and environment status.

Install CodeIgniter on Linux Mint 22

Verification Checklist

Confirm these elements work correctly:

Welcome page loads: Displays CodeIgniter 4 branding and version
Clean URLs function: Routes work without index.php in the URL
Database connectivity: No database-related errors in logs
File permissions: Writable directories accept new files
Error reporting: Detailed errors appear in development mode

Creating Your First Controller

Generate a test controller to verify functionality:

php spark make:controller TestController

Edit app/Controllers/TestController.php:

<?php

namespace App\Controllers;

class TestController extends BaseController
{
    public function index()
    {
        return view('test_view', ['message' => 'CodeIgniter is working perfectly!']);
    }
}

Create the corresponding view at app/Views/test_view.php:

<!DOCTYPE html>
<html>
<head>
    <title>CodeIgniter Test</title>
</head>
<body>
    <h1><?= $message ?></h1>
    <p>Your CodeIgniter installation is successful!</p>
</body>
</html>

Add a route in app/Config/Routes.php:

$routes->get('/test', 'TestController::index');

Visit http://codeigniter.local/test to see your custom page.

Troubleshooting Common Installation Issues

Apache Configuration Problems

500 Internal Server Error Solutions:

Check .htaccess file: Ensure the public/.htaccess file exists and contains proper rewrite rules
Verify mod_rewrite: Confirm the module is enabled with apache2ctl -M | grep rewrite
File permissions: Verify correct ownership and permissions on all directories
Apache error logs: Check /var/log/apache2/error.log for specific error messages

Database Connection Issues

Common database problems and solutions:

Authentication failures: Verify username and password in .env file
Service status: Ensure MariaDB/MySQL is running with systemctl status mariadb
Port conflicts: Check if the database is listening on the correct port (3306)
Host restrictions: Verify the database user has proper host permissions

PHP Extension Problems

Missing extension errors:

# Check installed PHP extensions
php -m

# Install missing extensions
sudo apt install php-extension-name

# Restart Apache after installation
sudo systemctl restart apache2

Composer and Memory Issues

Composer memory exhaustion solutions:

# Temporarily increase PHP memory limit
php -d memory_limit=512M /usr/local/bin/composer install

# Permanent solution in php.ini
memory_limit = 512M

File Permission Troubleshooting

Systematic permission fixing:

# Reset all permissions
sudo chown -R www-data:www-data /var/www/html/my-codeigniter-app
find /var/www/html/my-codeigniter-app -type d -exec chmod 755 {} \;
find /var/www/html/my-codeigniter-app -type f -exec chmod 644 {} \;
chmod -R 777 /var/www/html/my-codeigniter-app/writable

Best Practices and Security Recommendations

Production Security Measures

Essential security configurations:

Environment mode: Change CI_ENVIRONMENT to production in .env
Debug mode: Disable detailed error reporting for public applications
File permissions: Use restrictive permissions (755 for directories, 644 for files)
Database security: Use strong passwords and limited user privileges
HTTPS implementation: Install and configure SSL certificates for encrypted connections

Performance Optimization Strategies

OPcache configuration in /etc/php/8.1/apache2/php.ini:

opcache.enable=1
opcache.memory_consumption=256
opcache.interned_strings_buffer=16
opcache.max_accelerated_files=10000
opcache.revalidate_freq=2

CodeIgniter caching configuration in app/Config/Cache.php:

public string $handler = 'file';  // or 'redis', 'memcached'
public int $ttl = 60;
public string $prefix = 'myapp_';

Development Workflow Enhancements

Useful Spark commands for development:

# Generate models, controllers, migrations
php spark make:model UserModel
php spark make:controller UserController
php spark make:migration CreateUsersTable

# Database operations
php spark migrate
php spark db:seed UserSeeder

# Clear application cache
php spark cache:clear

Backup and Version Control

Git repository initialization:

cd /var/www/html/my-codeigniter-app
git init
git add .
git commit -m "Initial CodeIgniter installation"

Database backup script:

#!/bin/bash
mysqldump -u ci_user -p codeigniter_db > backup_$(date +%Y%m%d_%H%M%S).sql

Congratulations! You have successfully installed CodeIgniter. Thanks for using this tutorial to install the latest version of CodeIgniter PHP framework on the Linux Mint 22 system. For additional help or useful information, we recommend you check the official CodeIgniter website.

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