composer "Failed to decode zlib stream"

 dockerFile 中安装composer....

RUN curl -s -f -L -o /tmp/installer.php https://raw.githubusercontent.com/composer/getcomposer.org/da290238de6d63faace0343efbdd5aa9354332c5/web/installer \
 && php -r " \
    \$signature = '669656bab3166a7aff8a7506b8cb2d1c292f042046c5a994c43155c0be6190fa0355160742ab2e1c88d40d5be660b410'; \
    \$hash = hash('SHA384', file_get_contents('/tmp/installer.php')); \
    if (!hash_equals(\$signature, \$hash)) { \
        unlink('/tmp/installer.php'); \
        echo 'Integrity check failed, installer is either corrupt or worse.' . PHP_EOL; \
        exit(1); \
    }" \
 && php /tmp/installer.php --no-ansi --install-dir=/usr/bin --filename=composer --version=${COMPOSER_VERSION} \
 && composer --ansi --version --no-interaction \
 && composer config -g repo.packagist composer https://packagist.phpcomposer.com \
 && rm -rf /tmp/* /tmp/.htaccess

执行到 

php /tmp/installer.php

报 "Failed to decode zlib stream" 

原因是：网络连接的问题 请使用代理～

参考：https://github.com/composer/composer/issues/4619