Yii 2 Framework Deployment and Usage Guide

Prerequisites

Runtime Requirements

PHP: Minimum version 7.4, recommended version 8.x
Web Server: Apache, Nginx, or any web server with PHP support
Database: MySQL, PostgreSQL, SQLite, or any database supported by PDO

Development Tools

Composer: For dependency management
Git: For version control
Command Line Interface: For running commands and scripts

Optional Dependencies

PHP Extensions: PDO, mbstring, intl, gd, curl, and others depending on your application needs
Cache Backend: Redis, Memcached, or other caching systems for improved performance

Installation

1. Clone the Repository

git clone https://github.com/yiisoft/yii2.git
cd yii2

2. Install Dependencies

composer install

3. Create Application

Yii 2 provides different application templates. Choose one based on your needs:

Basic Application Template:

composer create-project yiisoft/yii2-app-basic basic

Advanced Application Template:

composer create-project yiisoft/yii2-app-advanced advanced

4. Initialize Application

cd basic
php init

Select 0 for development environment or 1 for production environment.

Configuration

Environment Variables

Create a .env file in your application root with the following configuration:

YII_DEBUG=true
YII_ENV=dev
DB_DSN=mysql:host=localhost;dbname=yii2basic
DB_USERNAME=root
DB_PASSWORD=

Database Configuration

Edit config/db.php to configure your database connection:

return [
    'class' => 'yii\db\Connection',
    'dsn' => 'mysql:host=localhost;dbname=yii2basic',
    'username' => 'root',
    'password' => '',
    'charset' => 'utf8',
];

Web Server Configuration

Apache: Enable mod_rewrite and create a .htaccess file in the web directory.

Nginx: Use the following configuration:

server {
    listen 80;
    server_name your-domain.com;
    root /path/to/basic/web;
    index index.php;

    location / {
        try_files $uri $uri/ /index.php?$query_string;
    }

    location ~ \.php$ {
        fastcgi_pass unix:/var/run/php/php8.0-fpm.sock;
        fastcgi_index index.php;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        include fastcgi_params;
    }
}

Build & Run

Development Mode

# Start development server
php yii serve

# Or use built-in PHP server
php -S localhost:8080 -t web/

Production Mode

# Set environment to production
php init --env=Production --overwrite=All

# Optimize Composer autoloader
composer dump-autoload --optimize

# Clear cache
php yii cache/flush-all

Running Migrations

# Apply all migrations
php yii migrate

# Apply specific migration
php yii migrate --migrationPath=@yii/rbac/migrations

Deployment

Platform Recommendations

Shared Hosting: Most shared hosting providers support PHP and MySQL. Upload files via FTP and configure database through hosting control panel.

VPS/Dedicated Server: Install PHP, web server, and database manually. Use process managers like PM2 for production.

Cloud Platforms:

AWS: Deploy on EC2 with RDS for database
DigitalOcean: Use LAMP/LEMP one-click apps
Heroku: Use PHP buildpack
Platform.sh: Native PHP support

Deployment Steps

Prepare Application

composer install --no-dev --optimize-autoloader
php init --env=Production --overwrite=All

Set Permissions

chmod 755 runtime web/assets
chmod 644 web/index.php

Configure Web Server Point web server document root to web/ directory.
Database Setup
```
php yii migrate/up --interactive=0
```
Enable HTTPS Use Let's Encrypt or your cloud provider's SSL certificates.

Troubleshooting

Common Issues

1. "Class not found" Errors

Ensure Composer autoloader is properly generated: composer dump-autoload
Check namespace declarations in your classes

2. Database Connection Issues

Verify database credentials in config/db.php
Ensure database server is running
Check if PDO extension is enabled

3. 404 Errors

Verify web server configuration points to web/ directory
Check .htaccess file for Apache
Ensure URL rewriting is enabled

4. Permission Issues

# Fix runtime directory permissions
chmod 777 runtime
chmod 777 web/assets

5. Memory Limit Exceeded

# Increase PHP memory limit
php -d memory_limit=-1 yii command

Debug Mode

Enable debug mode in config/web.php:

$config = [
    'id' => 'basic',
    'basePath' => dirname(__DIR__),
    'bootstrap' => ['log'],
    'components' => [
        'debug' => [
            'class' => 'yii\debug\Module',
            'allowedIPs' => ['127.0.0.1', '::1', '192.168.0.*'],
        ],
    ],
];

Logging

Check application logs in runtime/logs/ directory for detailed error information.

Performance Issues

Enable caching: Redis or Memcached
Optimize database queries
Use Gzip compression
Enable opcode caching (OPcache)

Security Considerations

Change default admin credentials
Set proper file permissions
Use HTTPS in production
Keep dependencies updated
Implement proper input validation and output encoding

How to Deploy & Use yiisoft/yii2