Warning: mysqli_real_connect(): php_network_getaddresses: getaddrinfo for db failed: Temporary failure in name resolution in /var/www/html/wp-includes/wp-db.php on line 1653

Fatal error: Uncaught mysqli_sql_exception: php_network_getaddresses: getaddrinfo for db failed: Temporary failure in name resolution in /var/www/html/wp-includes/wp-db.php:1653
Stack trace:
#0 /var/www/html/wp-includes/wp-db.php(1653): mysqli_real_connect(Object(mysqli), 'db', 'wordpress', Object(SensitiveParameterValue), NULL, NULL, NULL, 0)
#1 /var/www/html/wp-includes/wp-db.php(632): wpdb->db_connect()
#2 /var/www/html/wp-includes/load.php(527): wpdb->__construct('wordpress', 'q3qgXNPZag-?9vT...', 'wordpress', 'db')
#3 /var/www/html/wp-settings.php(124): require_wp_db()
#4 /var/www/html/wp-config.php(97): require_once('/var/www/html/w...')
#5 /var/www/html/wp-load.php(37): require_once('/var/www/html/w...')
#6 /var/www/html/wp-blog-header.php(13): require_once('/var/www/html/w...')
#7 /var/www/html/index.php(17): require('/var/www/html/w...')
#8 {main}
  thrown in /var/www/html/wp-includes/wp-db.php on line 1653