Add support for extra settings in composer.json for docker-compose.yml

src/Handler.php

@@ -117,6 +117,11 @@ class Handler {
       if (!$fs->exists($file)) {
         $twig_loader->setTemplate($template, file_get_contents($pluginRoot . '/templates/' . $template . '.twig'));
         $rendered = $twig->render($template, $options);
+        if (!empty($def['add2yaml']) && isset($options[$template])) {
+          $yaml = Yaml::parse($rendered);
+          $yaml  = array_merge_recursive($yaml, $options[$template]);
+          $rendered = Yaml::dump($yaml, 9, 2);
+        }
         file_put_contents($file, $rendered);
       }
       if (isset($def['link']) && ($def['link'] != $settingsPath)) {
@@ -200,6 +205,7 @@ class Handler {
       ],
       'docker-compose.yml' => [
         'dest' => $projectRoot,
+        'add2yaml' => TRUE,
       ],
       'aliases.drushrc.php' => [
         'dest' => $projectRoot . '/drush',