Gracefully handle FileNotFoundError exceptions

jail2ban/__init__.py

@@ -139,6 +139,14 @@ def create_app():
         app.logger.fatal(error)
         return jsonify({'error': str(error)}), 500
 
+    @app.errorhandler(FileNotFoundError)
+    def filenotfound_err(error):
+        '''
+        Show a json parsable error if the value is illegal
+        '''
+        app.logger.fatal(error)
+        return jsonify({'error': str(error)}), 500
+
     @auth.error_handler
     def auth_error():
         app.logger.error('Access Denied')

tests/test_flush.py

@@ -52,3 +52,19 @@ def test_wrong_method(client, mocker):
                           headers={"Authorization": "Basic " + valid_credentials})
 
     assert response.status_code == 405
+
+
+def test_filenotfound(app, mocker):
+
+    app.config.update({
+        "AUTHFILE": '../tests/nonexistent-users-test.txt'
+    })
+
+    client = app.test_client()
+
+    valid_credentials = base64.b64encode(b"test.example.com:testpassword").decode("utf-8")
+    name = 'nonexistent'
+    response = client.get(f"/flush/{name}",
+                          headers={"Authorization": "Basic " + valid_credentials})
+
+    assert response.status_code == 500