Docker 安装Composer
1. 下载
curl -sS https://getcomposer.org/installer | php
或者
https://mirrors.aliyun.com/composer/composer.phar
2. 设置到全局
mv composer.phar /usr/local/bin/composer
3. 配置国内镜像
composer config -g repo.packagist composer https://mirrors.aliyun.com/composer/
4. 测试
composer