Read external DB config from Dotenv environment

contao/dca/tl_calendar_events.php

@@ -145,7 +145,7 @@ $dca['fields']['export'] = [
 
 $dca['fields']['evlks_access'] = [
     'label'     => &$GLOBALS['TL_LANG']['tl_calendar_events']['evlks_access'],
-    'exclude'   => false,
+    'exclude'   => true,
     'inputType' => 'select',
     'options'   => [
         1 => 'Veranstaltung in Gebaerdensprache bzw. Gebaerdendolmetscher ist anwesend',

src/Model/ExternalLocationModel.php

@@ -6,6 +6,13 @@ use PDO;
 
 class ExternalLocationModel
 {
+    private static function readEnv(string $key): string
+    {
+        $value = $_SERVER[$key] ?? $_ENV[$key] ?? getenv($key);
+
+        return is_string($value) ? trim($value) : '';
+    }
+
     /**
      * Erstellt die PDO-Verbindung zur externen Datenbank.
      *
@@ -13,9 +20,9 @@ class ExternalLocationModel
      */
     private static function getConnection()
     {
-        $dsn = getenv('KS_NOSSENERLAND_EXTERNAL_DB_DSN') ?: '';
+        $dsn = self::readEnv('KS_NOSSENERLAND_EXTERNAL_DB_DSN');
-        $user = getenv('KS_NOSSENERLAND_EXTERNAL_DB_USER') ?: '';
+        $user = self::readEnv('KS_NOSSENERLAND_EXTERNAL_DB_USER');
-        $password = getenv('KS_NOSSENERLAND_EXTERNAL_DB_PASSWORD') ?: '';
+        $password = self::readEnv('KS_NOSSENERLAND_EXTERNAL_DB_PASSWORD');
 
         if ('' === $dsn || '' === $user) {
             throw new \PDOException('Missing external DB env vars for location lookup.');