Manage multiple types of logs in Symfony

Here’s the complete implementation that allows you to select a logger dynamically based on the APP_LOGGER_TYPE environment variable. This includes the logger interface, logger implementations, user service, user controller, and the service configuration in services.yaml.

1. Logger Interface

File: src/Service/Logger/LoggerInterface.php

namespace App\Service\Logger;

interface LoggerInterface
{
    public function log(string $message): void;
}

2. File Logger Implementation

File: src/Service/Logger/FileLogger.php

namespace App\Service\Logger;

class FileLogger implements LoggerInterface
{
    private string $logFile;

    public function __construct(string $logFile = 'app.log')
    {
        $this->logFile = $logFile;
    }

    public function log(string $message): void
    {
        file_put_contents($this->logFile, $message . PHP_EOL, FILE_APPEND);
    }
}

3. Database Logger Implementation

File: src/Service/Logger/DatabaseLogger.php

namespace App\Service\Logger;

use Doctrine\ORM\EntityManagerInterface;
use App\Entity\LogEntry;

class DatabaseLogger implements LoggerInterface
{
    private EntityManagerInterface $entityManager;

    public function __construct(EntityManagerInterface $entityManager)
    {
        $this->entityManager = $entityManager;
    }

    public function log(string $message): void
    {
        $logEntry = new LogEntry();
        $logEntry->setMessage($message);
        $logEntry->setCreatedAt(new \DateTime());

        $this->entityManager->persist($logEntry);
        $this->entityManager->flush();
    }
}

4. Email Logger Implementation (Optional)

File: src/Service/Logger/EmailLogger.php

namespace App\Service\Logger;

class EmailLogger implements LoggerInterface
{
    public function log(string $message): void
    {
        // Implement email logging logic here
        // e.g., sending an email with the log message
        mail('admin@example.com', 'Log Entry', $message);
    }
}

5. User Service

File: src/Service/UserService.php

namespace App\Service;

use App\Service\Logger\LoggerInterface;

class UserService
{
    private LoggerInterface $logger;

    public function __construct(LoggerInterface $logger)
    {
        $this->logger = $logger;
    }

    public function createUser(string $username): void
    {
        $this->logger->log("User $username created.");
    }
}

6. User Controller

File: src/Controller/UserController.php

namespace App\Controller;

use App\Service\UserService;
use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\HttpFoundation\Response;

class UserController extends AbstractController
{
    private UserService $userService;

    public function __construct(UserService $userService)
    {
        $this->userService = $userService;
    }

    public function create(): Response
    {
        $this->userService->createUser('JohnDoe'); // Uses the injected logger
        return new Response('User created and logged.');
    }
}

7. Entity Class for Log Entry (Optional)

File: src/Entity/LogEntry.php

namespace App\Entity;

use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\Entity()
 */
class LogEntry
{
    /**
     * @ORM\Id
     * @ORM\GeneratedValue
     * @ORM\Column(type="integer")
     */
    private int $id;

    /**
     * @ORM\Column(type="string")
     */
    private string $message;

    /**
     * @ORM\Column(type="datetime")
     */
    private \DateTime $createdAt;

    public function setMessage(string $message): void
    {
        $this->message = $message;
    }

    public function setCreatedAt(\DateTime $createdAt): void
    {
        $this->createdAt = $createdAt;
    }
}

8. Configure Services in services.yaml

File: config/services.yaml

parameters:
    log_file: 'app.log'  # Default log file location

services:
    # Conditional service based on APP_LOGGER_TYPE
    App\Service\Logger\LoggerInterface: '@=service("App\Service\Logger\\" . ucfirst(getenv("APP_LOGGER_TYPE")) . "Logger")'

    App\Service\Logger\DatabaseLogger:
        arguments:
            $entityManager: '@doctrine.orm.entity_manager'

    App\Service\Logger\FileLogger:
        arguments:
            $logFile: '%log_file%'  # Use the default log file from parameters

    App\Service\Logger\EmailLogger: ~ # Add EmailLogger service if necessary

    App\Service\UserService:
        arguments:
            $logger: '@=service("App\Service\Logger\\" . ucfirst(getenv("APP_LOGGER_TYPE")) . "Logger")'

9. Update Your .env File

Set the desired default logger in your .env file:

File: .env

APP_LOGGER_TYPE=file  # or database, or email

Summary

With this setup:

• You can easily switch between different logging mechanisms by simply changing the value of APP_LOGGER_TYPE in your .env file.
• The services.yaml configuration dynamically selects the appropriate logger implementation based on the environment variable, enabling you to use different logging strategies without modifying the service or application logic.