Running Your App

A CodeIgniter 4 app can be run in a number of different ways: hosted on a web server, using virtualization, or using CodeIgniter’s command line tool for testing. This section addresses how to use each technique, and explains some of the pros and cons of them.

Important

You should always be careful about the case of filenames. Many developers develop on case-insensitive file systems on Windows or macOS. However, most server environments use case-sensitive file systems. If the file name case is incorrect, code that works locally will not work on the server.

If you’re new to CodeIgniter, please read the Getting Started section of the User Guide to begin learning how to build dynamic PHP applications. Enjoy!

Initial Configuration 

Configure for Your Site URIs 

Open the app/Config/App.php file with a text editor.

$baseURL
Set your base URL to $baseURL. If you need more flexibility, the baseURL may be set within the .env file as app.baseURL = 'http://example.com/'. Always use a trailing slash on your base URL!

Note

If you don’t set the baseURL correctly, in development mode, the debug toolbar may not load properly and web pages may take considerably longer to display.
$indexPage
If you don’t want to include index.php in your site URIs, set $indexPage to ''. The setting will be used when the framework generates your site URIs.

Note

You may need to configure your web server to access your site with a URL that does not contain index.php. See CodeIgniter URLs.

Configure Database Connection Settings 

If you intend to use a database, open the app/Config/Database.php file with a text editor and set your database settings. Alternately, these could be set in your .env file.

Set to Development Mode 

If it is not on the production server, set CI_ENVIRONMENT to development in .env file to take advantage of the debugging tools provided. See Setting Development Mode for the detail.

Important

In production environments, you should disable error display and any other development-only functionality. In CodeIgniter, this can be done by setting the environment to “production”. By default, the application will run using the “production” environment. See also The ENVIRONMENT Constant.

Set Writable Folder Permission 

If you will be running your site using a web server (e.g., Apache or nginx), you will need to modify the permissions for the writable folder inside your project, so that it is writable by the user or account used by your web server.

Local Development Server 

CodeIgniter 4 comes with a local development server, leveraging PHP’s built-in web server with CodeIgniter routing. You can launch it, with the following command line in the main directory:

php spark serve

This will launch the server and you can now view your application in your browser at http://localhost:8080.

Note

The built-in development server should only be used on local development machines. It should NEVER be used on a production server.

If you need to run the site on a host other than simply localhost, you’ll first need to add the host to your hosts file. The exact location of the file varies in each of the main operating systems, though all unix-type systems (including macOS) will typically keep the file at /etc/hosts.

The local development server can be customized with three command line options:

You can use the --host CLI option to specify a different host to run the application at:
php spark serve --host example.dev
By default, the server runs on port 8080 but you might have more than one site running, or already have another application using that port. You can use the --port CLI option to specify a different one:
php spark serve --port 8081
You can also specify a specific version of PHP to use, with the --php CLI option, with its value set to the path of the PHP executable you want to use:
php spark serve --php /usr/bin/php7.6.5.4

Hosting with Apache 

A CodeIgniter4 webapp is normally hosted on a web server. Apache HTTP Server is the “standard” platform, and assumed in much of our documentation.

Apache is bundled with many platforms, but can also be downloaded in a bundle with a database engine and PHP from Bitnami.

Configure Main Config File 

Enabling mod_rewrite 

The “mod_rewrite” module enables URLs without “index.php” in them, and is assumed in our user guide.

Make sure that the rewrite module is enabled (uncommented) in the main configuration file, e.g., apache2/conf/httpd.conf:

LoadModule rewrite_module modules/mod_rewrite.so

Setting Document Root 

Also make sure that the default document root’s <Directory> element enables this too, in the AllowOverride setting:

<Directory "/opt/lamp/apache2/htdocs">
    Options Indexes FollowSymLinks
    AllowOverride All
    Require all granted
</Directory>

Hosting with VirtualHost 

We recommend using “virtual hosting” to run your apps. You can set up different aliases for each of the apps you work on,

Enabling vhost_alias_module 

Make sure that the virtual hosting module is enabled (uncommented) in the main configuration file, e.g., apache2/conf/httpd.conf:

LoadModule vhost_alias_module modules/mod_vhost_alias.so

Adding Host Alias 

Add a host alias in your “hosts” file, typically /etc/hosts on unix-type platforms, or c:WindowsSystem32driversetchosts on Windows.

Add a line to the file. This could be myproject.local or myproject.test, for instance:

127.0.0.1 myproject.local

Setting VirtualHost 

Add a <VirtualHost> element for your webapp inside the virtual hosting configuration, e.g., apache2/conf/extra/httpd-vhost.conf:

<VirtualHost *:80>
    DocumentRoot "/opt/lamp/apache2/myproject/public"
    ServerName   myproject.local
    ErrorLog     "logs/myproject-error_log"
    CustomLog    "logs/myproject-access_log" common

    <Directory "/opt/lamp/apache2/myproject/public">
        AllowOverride All
        Require all granted
    </Directory>
</VirtualHost>

The above configuration assumes the project folder is located as follows:

apache2/
   ├── myproject/      (Project Folder)
   │      └── public/  (DocumentRoot for myproject.local)
   └── htdocs/

Restart Apache.

Testing 

With the above configuration, your webapp would be accessed with the URL http://myproject.local/ in your browser.

Apache needs to be restarted whenever you change its configuration.

Hosting with Subfolder 

If you want a baseURL like http://localhost/myproject/ with a subfolder, there are three ways.

Making Symlink 

Place your project folder as follows, where htdocs is the Apache document root:

├── myproject/ (project folder)
│      └── public/
└── htdocs/

Navigate to the htdocs folder and create a symbolic link as follows:

cd htdocs/
ln -s ../myproject/public/ myproject

Using Alias 

Place your project folder as follows, where htdocs is the Apache document root:

├── myproject/ (project folder)
│      └── public/
└── htdocs/

Add the following in the main configuration file, e.g., apache2/conf/httpd.conf:

Alias /myproject /opt/lamp/apache2/myproject/public
<Directory "/opt/lamp/apache2/myproject/public">
    AllowOverride All
    Require all granted
</Directory>

Restart Apache.

Adding .htaccess 

The last resort is to add .htaccess to the project root.

It is not recommended that you place the project folder in the document root. However, if you have no other choice, like on a shared server, you can use this.

Place your project folder as follows, where htdocs is the Apache document root, and create the .htaccess file:

└── htdocs/
    └── myproject/ (project folder)
        ├── .htaccess
        └── public/

And edit .htaccess as follows:

<IfModule mod_rewrite.c>
    RewriteEngine On
    RewriteRule ^(.*)$ public/$1 [L]
</IfModule>

<FilesMatch "^\.">
    Require all denied
    Satisfy All
</FilesMatch>

Hosting with mod_userdir (Shared Hosts)

A common practice in shared hosting environments is to use the Apache module “mod_userdir” to enable per-user Virtual Hosts automatically. Additional configuration is required to allow CodeIgniter4 to be run from these per-user directories.

The following assumes that the server is already configured for mod_userdir. A guide to enabling this module is available in the Apache documentation.

Because CodeIgniter4 expects the server to find the framework front controller at public/index.php by default, you must specify this location as an alternative to search for the request (even if CodeIgniter4 is installed within the per-user web directory).

The default user web directory ~/public_html is specified by the UserDir directive, typically in apache2/mods-available/userdir.conf or apache2/conf/extra/httpd-userdir.conf:

UserDir public_html

So you will need to configure Apache to look for CodeIgniter’s public directory first before trying to serve the default:

UserDir "public_html/public" "public_html"

Be sure to specify options and permissions for the CodeIgniter public directory as well. A userdir.conf might look like:

<IfModule mod_userdir.c>
    UserDir "public_html/public" "public_html"
    UserDir disabled root

    <Directory /home/*/public_html>
        AllowOverride All
        Options MultiViews Indexes FollowSymLinks
        <Limit GET POST OPTIONS>
            # Apache <= 2.2:
            # Order allow,deny
            # Allow from all

            # Apache >= 2.4:
            Require all granted
        </Limit>
        <LimitExcept GET POST OPTIONS>
            # Apache <= 2.2:
            # Order deny,allow
            # Deny from all

            # Apache >= 2.4:
            Require all denied
        </LimitExcept>
    </Directory>

    <Directory /home/*/public_html/public>
        AllowOverride All
        Options MultiViews Indexes FollowSymLinks
        <Limit GET POST OPTIONS>
            # Apache <= 2.2:
            # Order allow,deny
            # Allow from all

            # Apache >= 2.4:
            Require all granted
        </Limit>
        <LimitExcept GET POST OPTIONS>
            # Apache <= 2.2:
            # Order deny,allow
            # Deny from all

            # Apache >= 2.4:
            Require all denied
        </LimitExcept>
    </Directory>
</IfModule>

Removing the index.php 

See CodeIgniter URLs.

Setting Environment 

See Handling Multiple Environments.

Hosting with nginx 

nginx is the second most widely used HTTP server for web hosting. Here you can find an example configuration using PHP 8.1 FPM (unix sockets) under Ubuntu Server.

default.conf 

This configuration enables URLs without “index.php” in them and using CodeIgniter’s “404 - File Not Found” for URLs ending with “.php”.

server {
    listen 80;
    listen [::]:80;

    server_name example.com;

    root  /var/www/example.com/public;
    index index.php index.html index.htm;

    location / {
        try_files $uri $uri/ /index.php$is_args$args;
    }

    location ~ \.php$ {
        include snippets/fastcgi-php.conf;

        # With php-fpm:
        fastcgi_pass unix:/run/php/php8.1-fpm.sock;
        # With php-cgi:
        # fastcgi_pass 127.0.0.1:9000;
    }

    error_page 404 /index.php;

    # deny access to hidden files such as .htaccess
    location ~ /\. {
        deny all;
    }
}

Setting Environment 

See Handling Multiple Environments.

Bootstrapping the App 

In some scenarios you will want to load the framework without actually running the whole application. This is particularly useful for unit testing your project, but may also be handy for using third-party tools to analyze and modify your code. The framework comes with a separate bootstrap script specifically for this scenario: system/Test/bootstrap.php.

Most of the paths to your project are defined during the bootstrap process. You may use pre-defined constants to override these, but when using the defaults be sure that your paths align with the expected directory structure for your installation method.