以下のdockerfileをdocker-compse経由でcakephp3の開発環境を作成しています。

cakephp3のplugin(muffin/trash, ceeram/cakephp-blame)を
composer requireでインストールしようとしているのですが、
なぜか/vendor配下にインストールされてしまいます。

解決方法がわからず、アドバイスいただけないでしょうか?


docker-compose.yml

version: '3.3'
volumes:
  mysql.db.volume:
services:
  mysql.db:
    restart: always
    image: mysql:5.7.19
    container_name: mysql.db
    command: mysqld --character-set-server=utf8 --collation-server=utf8_unicode_ci
    volumes:
      - mysql.db.volume:/var/lib/mysql
    environment:
      MYSQL_DATABASE: 'hoge_db'
      MYSQL_USER : 'hoge'
      MYSQL_PASSWORD: 'hoge'
      MYSQL_ROOT_PASSWORD: 'password'
      TZ: "Asia/Tokyo"
    ports:
      - '33306:3306'

  cakephp.web:
    container_name: cakephp.web
    build: ./docker-image
    privileged: true
    ports:
      - '8001:80'
      - '2223:22'
    depends_on:
      - mysql.db
    links:
      - mysql.db

Dockerfile

FROM centos:7

#time setting
RUN \cp -fp /usr/share/zoneinfo/Japan /etc/localtime

#prepare
RUN yum install -y unzip

# Add yum repositories. (epel and remi)
RUN rpm -Uvh http://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm && \
    rpm -Uvh http://rpms.famillecollet.com/enterprise/remi-release-7.rpm
RUN yum install -y epel-release
RUN yum update -y epel-release

#php7 install
#RUN yum install -y --enablerepo=remi-php71,epel php php-cli php-common php-devel php-fpm php-gd php-gmp php-intl php-mbstring php-mcrypt php-mysql php-opcache php-pdo php-pear-MDB2-Driver-mysqli php-pecl-memcached php-pecl-msgpack php-pecl-xdebug php-phpunit-PHPUnit php-xml
RUN yum install -y --enablerepo=remi-php71,epel php php-cli php-common php-devel php-fpm php-gd php-gmp php-intl php-mbstring php-mcrypt php-mysql php-opcache php-pdo php-pecl-memcached php-pecl-msgpack php-pecl-xdebug php-phpunit-PHPUnit php-xml

#composer install
RUN curl -sS https://getcomposer.org/installer | php
RUN mv composer.phar /usr/local/bin/composer

#git install
RUN yum install -y git

#cakephp install
RUN cd /var
RUN composer create-project --prefer-dist -n cakephp/app /var/web_app
RUN ln -s /var/phm_app/webroot /var/www/html/phm
#COPY var/cakephp/webroot/.htaccess /var/phm_app/webroot/.htaccess

#plugin install
RUN cd /var/web_app
RUN composer require muffin/trash
RUN composer require ceeram/cakephp-blame

#httpd install
RUN yum install -y httpd
RUN yum install -y httpd-devel
#COPY etc/httpd/conf.d/phm.conf /etc/httpd/conf.d/phm.conf

#ssh install
RUN yum install -y openssh-server
RUN passwd -d root
#COPY etc/sshd_config /etc/ssh/sshd_config

#service service entry
RUN systemctl enable httpd
RUN systemctl enable sshd

#post processing
VOLUME ["/var/www/html"]
CMD ["/sbin/init"]

Dockerfileの #plugin install の部分で、cdした先の/var/web_app/vendor下にインストールされず、(ルート)/vendor配下にインストールされます。