anchor.diff:      && rm -rf /var/lib/apt/lists/*
   
   # grab gosu for easy step-down from root
  -ENV GOSU_VERSION 1.9
   RUN set -x \
  +    && export GOSU_VERSION=1.10 \
       && apt-get update && apt-get install -y --no-install-recommends wget && rm -rf /var/lib/apt/lists/* \
       && wget -O /usr/local/bin/gosu "https://github.com/tianon/gosu/releases/download/$GOSU_VERSION/gosu-$(dpkg --print-architecture)" \
       && wget -O /usr/local/bin/gosu.asc "https://github.com/tianon/gosu/releases/download/$GOSU_VERSION/gosu-$(dpkg --print-architecture).asc" \
  
positive.code:     && apt-get purge -y --auto-remove wget
  
  # grab tini for signal processing and zombie killing
  ENV TINI_VERSION v0.9.0
  RUN set -x \
      && apt-get update && apt-get install -y --no-install-recommends wget && rm -rf /var/lib/apt/lists/* \
      && wget -O /usr/local/bin/tini "https://github.com/krallin/tini/releases/download/$TINI_VERSION/tini" \
      && wget -O /usr/local/bin/tini.asc "https://github.com/krallin/tini/releases/download/$TINI_VERSION/tini.asc" \
      && export GNUPGHOME="$(mktemp -d)" \
      && gpg --keyserver ha.pool.sks-keyservers.net --recv-keys 6380DC428747F6C393FEACA59A84159D7001A4E5 \
      && gpg --batch --verify /usr/local/bin/tini.asc /usr/local/bin/tini \
  
negative.code:     && make -C /usr/src/redis install \
      && rm -r /usr/src/redis
  
  RUN set -x \
      && export DOCKER_VERSION=1.12.3 \
      && export DOCKER_SHA256=626601deb41d9706ac98da23f673af6c0d4631c4d194a677a9a1a07d7219fa0f \
      && apt-get update && apt-get install -y --no-install-recommends wget && rm -rf /var/lib/apt/lists/* \
      && wget -O docker.tgz "https://get.docker.com/builds/Linux/x86_64/docker-$DOCKER_VERSION.tgz" \
      && echo "${DOCKER_SHA256} *docker.tgz" | sha256sum -c - \
      && tar -zxvf docker.tgz \
      && mv docker/* /usr/local/bin/ \
      && rmdir docker \
      && rm docker.tgz \
      && docker -v \
      && apt-get purge -y --auto-remove wget
  
  ENV DOCKER_HOST tcp://docker:2375
  
  