How can i inject dependencies to Symfony Console commands?

Since Symfony 4.2 the ContainerAwareCommand is deprecated. Use the DI instead.

namespace App\Command;

use Symfony\Component\Console\Command\Command;
use Doctrine\ORM\EntityManagerInterface;

final class YourCommand extends Command
{
    /**
     * @var EntityManagerInterface
     */
    private $entityManager;

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

        parent::__construct();
    }

    protected function execute(InputInterface $input, OutputInterface $output)
    {
        // YOUR CODE
        $this->entityManager->persist($object1);    
    }
}