anchor.diff:  # Libs -y --no-install-recommends
   RUN apt-get update \
       && apt-get install -y \
  -        curl wget git zip unzip less vim procps lsof tcpdump htop openssl \
  +  curl wget git zip unzip less vim procps lsof tcpdump htop openssl net-tools iputils-ping \
           libz-dev \
           libssl-dev \
           libnghttp2-dev \
  
positive.code:         libfreetype6-dev \
  # Install PHP extensions
      && docker-php-ext-install \
         bcmath gd pdo_mysql mbstring sockets zip sysvmsg sysvsem sysvshm
  
  # Install composer
  Run curl -sS https://getcomposer.org/installer | php \
  
negative.code: # --build-arg timezone=Asia/Shanghai
  ARG timezone
  # app env: prod pre test dev
  ARG app_env=test
  # default use www-data user
  ARG work_user=www-data
  
  # default APP_ENV = test
  ENV APP_ENV=${app_env:-"test"} \
      TIMEZONE=${timezone:-"Asia/Shanghai"} \
      PHPREDIS_VERSION=5.1.0 \
      SWOOLE_VERSION=4.4.17 \
  