Dockerでのcomposerのインストールエラーの対処

発生したエラー

$ docker-compose up -d
 ...
ERROR: Service 'web' failed to build: The command '/bin/sh -c php composer-setup.php' returned a non-zero code: 1

修正前のDockerFile

# install composer
RUN php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"
RUN php -r "if (hash_file('sha384', 'composer-setup.php') === 'e5325b19b381bfd88ce90a5ddb7823406b2a38cff6bb704b0acc289a09c8128d4a8ce2bbafcd1fcbdc38666422fe2806') { echo 'Installer verified'; } else { echo 'Installer corrupt'; unlink('composer-setup.php'); } echo PHP_EOL;"
RUN php composer-setup.php
RUN php -r "unlink('composer-setup.php');"

修正後のDockerFile

# install composer
COPY --from=composer:latest /usr/bin/composer /usr/bin/composer