user and pw as env vars

init.php

@@ -1,4 +1,10 @@
 <?php
+
+$host = 'webgis-db'; // Matches the service name in docker-compose
+$db   = getenv('POSTGRES_DB');
+$user = getenv('POSTGRES_USER');
+$pass = getenv('POSTGRES_PASSWORD');
+
     ob_start();
     session_start();
 
@@ -10,8 +16,8 @@
             PDO::ATTR_EMULATE_PREPARES   => false
         ];
 
-        $dsn = "pgsql:host=localhost;dbname=WebGIS;port=5432";
-        $pdo = new PDO($dsn, 'postgres', '1a2b3c4d5e6f', $opt);
+        $dsn = "pgsql:host=localhost;dbname=$db;port=5432";
+        $pdo = new PDO($dsn, $user, $pass, $opt);
     
     // Error-Message
     } catch(PDOException $e) {