redmine-bundle/src/DependencyInjection/Configuration.php

<?php declare(strict_types=1);

namespace Magdev\RedmineBundle\DependencyInjection;

use Symfony\Component\Config\Definition\Builder\TreeBuilder;
use Symfony\Component\Config\Definition\ConfigurationInterface;

/**
 * @author Marco Grätsch <magdev3.0@gmail.com>
 */
final class Configuration implements ConfigurationInterface
{
    public function getConfigTreeBuilder(): TreeBuilder
    {
        $treeBuilder = new TreeBuilder('magdev_redmine');
        $rootNode = $treeBuilder->getRootNode();
        $rootNode->fixXmlConfig('connections')
            ->children()
                ->arrayNode('connections')
                    ->useAttributeAsKey('name')
                    ->normalizeKeys(false)
                    ->arrayPrototype()
                        ->children()
                            ->scalarNode('url')
                                ->isRequired()
                                ->info('The URL of your Redmine instance')
                            ->end()
                            ->scalarNode('apikey')
                                ->isRequired()
                                ->info('Your Redmine API-Key')
                            ->end()
                        ->end()
                    ->end()
                ->end()
                ->scalarNode('default_connection')->end()
        ;

        return $treeBuilder;
    }
}