Fatal error: Uncaught PDOException: PDO::__construct(): php_network_getaddresses: getaddrinfo for db failed: Temporary failure in name resolution in /var/www/html/flashcard-system/conexion.php:3 Stack trace: #0 /var/www/html/flashcard-system/conexion.php(3): PDO->__construct('mysql:host=db; ...', 'root', 'password') #1 /var/www/html/flashcard-system/index.php(26): include('/var/www/html/f...') #2 {main} Next PDOException: SQLSTATE[HY000] [2002] php_network_getaddresses: getaddrinfo for db failed: Temporary failure in name resolution in /var/www/html/flashcard-system/conexion.php:3 Stack trace: #0 /var/www/html/flashcard-system/conexion.php(3): PDO->__construct('mysql:host=db; ...', 'root', 'password') #1 /var/www/html/flashcard-system/index.php(26): include('/var/www/html/f...') #2 {main} thrown in /var/www/html/flashcard-system/conexion.php on line 3