diff --git a/.gitignore b/.gitignore
index 2c4705b..37b20b1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,3 @@
-config.php
+config*.php*
 vendor/
 twig_cache/
-metrics_cache.json
diff --git a/index.php b/index.php
index 98ec797..aebf766 100644
--- a/index.php
+++ b/index.php
@@ -1,8 +1,16 @@
 <?php
 require 'vendor/autoload.php';
-require 'config.php';
-if(file_exists('metrics_cache.json')) {
-    $oldconfig = json_decode(file_get_contents('metrics_cache.json'), true);
+$configFile = getenv('CONFIG_FILE') ?: 'config.php';
+$cacheFile = $configFile . '.cache.json';
+
+if (file_exists($configFile)) {
+    require ($configFile);
+} else {
+    echo ("Configuration file not found: " . $configFile);
+    exit(1);
+}
+if(file_exists($cacheFile)) {
+    $oldconfig = json_decode(file_get_contents($cacheFile), true);
 } else {
     $oldconfig = [];
 }
@@ -95,7 +103,7 @@ if(php_sapi_name() == 'cli' || $_SERVER["REQUEST_URI"] == '/metrics') {
         }
     }
 
-    file_put_contents('metrics_cache.json', json_encode($config, JSON_PRETTY_PRINT));
+    file_put_contents($cacheFile, json_encode($config, JSON_PRETTY_PRINT));
 
     $loader = new \Twig\Loader\FilesystemLoader('templates');
     $twig = new \Twig\Environment($loader, [