This image contain php-7.0 based on alpine with xDebug enabled and Composer installed

PHP 7.0.32 (fpm-fcgi) (built: Nov 16 2018 07:04:33)
Copyright (c) 1997-2017 The PHP Group
Zend Engine v3.0.0, Copyright (c) 1998-2017 Zend Technologies
    with Xdebug v2.6.1, Copyright (c) 2002-2018, by Derick Rethans

Also it has the following modules:

[PHP Modules] Core ctype curl date dom fileinfo filter ftp hash iconv json libxml mbstring mcrypt mysqlnd openssl pcre PDO pdo_mysql pdo_sqlite Phar posix readline redis Reflection session SimpleXML soap sodium SPL sqlite3 standard tokenizer xdebug xml xmlreader xmlwriter zlib

[Zend Modules] Xdebug