Using .env File in CodeIgniter 3

Learn how to use the .env file in CodeIgniter 3 to securely manage your environment variables and improve your application’s configuration structure.

Using environment variables via a .env file is a common best practice to keep sensitive configuration (like database credentials or any other secret or api keys) out of your codebase. .env file support is not provided in CodeIgniter 3 out of the box, but you can easily integrate it using the vlucas/phpdotenv library.

This guide will show you how to add .env file support in a CodeIgniter 3 application using the vlucas/phpdotenv library with Composer autoload enabled.

Prerequisites

Ensure your CodeIgniter project has Composer enabled by checking the following in application/config/config.php:

$config['composer_autoload'] = TRUE;

Step-by-Step Setup

The following are the steps to implement .env file support.

Step 1. Install vlucas/phpdotenv via Composer

In Codeigniter 3, composer.json is not available at the project root, but inside the application directory. So, to install any composer library, you have to first navigate to the application directory.

cd application/
composer require vlucas/phpdotenv

It will install the core files to add support for .env files.

Step 2. Create the .env File

At the root of your project (same level as index.php), create a file named .env with database configuration variables as a content:

DB_HOST=localhost
DB_USERNAME=root
DB_PASSWORD=secret
DB_NAME=my_database

3. Load the .env in index.php

Open your index.php file and add the following code before the line that bootstraps CodeIgniter:

require_once __DIR__ . '/vendor/autoload.php';

$dotenv = Dotenv\Dotenv::createImmutable(__DIR__);
$dotenv->load();

Add the above code in index.php file before the following line:

require_once BASEPATH.'core/CodeIgniter.php';

For older versions (PHP < 7.1 or Dotenv v2):

$dotenv = new Dotenv\Dotenv(__DIR__);
$dotenv->load();

This will load the .env file variables using the phpdotenv library. Now, all the variables used in .env file can be used in any code of the project.

4. Use Environment Variables in database.php

We defined the database configuration variables inside the .env file. To use these variables, open application/config/database.php and update the code as follows:

$db['default'] = array(
    'hostname' => getenv('DB_HOST'),
    'username' => getenv('DB_USERNAME'),
    'password' => getenv('DB_PASSWORD'),
    'database' => getenv('DB_NAME'),
    'dbdriver' => 'mysqli',
    'db_debug' => (ENVIRONMENT !== 'production'),
    // ... other settings
);

Note: In some cases, getenv function may not work. Use $_ENV as an alternative.

Secutiry Tip

Never commit your .env file to version control. Add it to .gitignore

Conclusion

Now your CodeIgniter 3 app can securely use environment variables just like modern frameworks. This keeps your config clean, safe, and easy to manage across environments.

How to Integrate Sentry with CodeIgniter 3

Learn how to integrate Sentry error tracking with CodeIgniter 3 to monitor and debug PHP application issues in real-time.

Sentry is a powerful error-tracking tool that helps you monitor and fix crashes in real-time. In this post, we’ll walk through how to integrate Sentry with a CodeIgniter 3 application and log all errors to sentry.

Prerequisites

Before you begin, make sure you have:

  • A Sentry account with a created project.
  • A working CodeIgniter 3 setup.
  • PHP 7.2+ (recommended).
  • Composer installed.

Step 1: Install Sentry SDK via Composer

Open your terminal and run:

composer require sentry/sentry

If you haven’t initialized Composer yet in your CI3 project, run composer init first.

Step 2: Enable and Configure Hooks

To enable hook in CodeIgniter 3, Edit your application/config/config.php and update the 'enable_hooks' variable to TRUE if it is FALSE.

$config['enable_hooks'] = TRUE;

Now, register the sentry hook into the application/config/hooks.php file:

$hook['pre_system'][] = array(
    'class'    => '',
    'function' => 'init_sentry', // Function to be called
    'filename' => 'sentry.php', // Filename of the hook
    'filepath' => 'hooks'
);

As mentioned in the hook file, create application/hooks/sentry.php and add the following code:

use Sentry\ClientBuilder;
use Sentry\State\Hub;

function init_sentry()
{
    require_once APPPATH . '../vendor/autoload.php';

    \Sentry\init([
        'dsn' => 'https://your-dsn@sentry.io/project-id',
        'environment' => ENVIRONMENT,
        'error_types' => E_ALL & ~E_NOTICE, // Adjust as needed
    ]);
}

Replace 'https://your-dsn@sentry.io/project-id' with your actual Sentry DSN.

Step 3: Capture Errors or Messages

Now, you can log errors to sentry using multiple ways as follows,

Manually Capture Exceptions

try {
    // Your code here
} catch (Exception $e) {
    \Sentry\captureException($e);
}

Manually Capture Messages

\Sentry\captureMessage('Something happened!', \Sentry\Severity::warning());

Step 4: Automatically Capture Uncaught Exceptions

You can log all uncaught exceptions by extending the CI Exception class.

Create a new exception file at application/core/MY_Exceptions.php and add the following content in it:

class MY_Exceptions extends CI_Exceptions
{
    public function show_exception($exception)
    {
        if (class_exists('\Sentry\State\Hub')) {
            \Sentry\captureException($exception);
        }

        return parent::show_exception($exception);
    }
}

This will overwrite the codeigniter exception to log errors in sentry.

Step 5: Test the Integration

To test the integration, add the following code to generate the fake exception:

throw new Exception("Testing Sentry in CI3");

You should see this exception appear in your Sentry dashboard almost immediately.

Pro Tips

  • Use .env files or config variables to store your DSN securely.
  • Configure environments like development, production, staging in the environment key of the config.
  • You can even capture user context (like logged-in user ID or email) with Sentry.

Conclusion

With this setup, your CodeIgniter 3 project is now integrated with Sentry for powerful real-time error tracking. From catching uncaught exceptions to manually logging messages, Sentry gives you the tools you need to debug faster and ship more reliably.

Have questions or need help capturing user context? Drop a comment below!