This image contain php-7.1 based on alpine with xDebug enabled and Composer installed

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 SPL sqlite3 standard tokenizer xdebug xml xmlreader xmlwriter zlib

[Zend Modules] Xdebug