anchor.diff:      && make -C /usr/src/redis install \
       && rm -r /usr/src/redis
   
  -ENV DOCKER_BUCKET get.docker.com
  -ENV DOCKER_VERSION 1.12.3
  -ENV DOCKER_SHA256 626601deb41d9706ac98da23f673af6c0d4631c4d194a677a9a1a07d7219fa0f
  -
   RUN set -x \
  -        && curl -fSL "https://${DOCKER_BUCKET}/builds/Linux/x86_64/docker-$DOCKER_VERSION.tgz" -o docker.tgz \
  -        && echo "${DOCKER_SHA256} *docker.tgz" | sha256sum -c - \
  -        && tar -zxvf docker.tgz \
  -        && mv docker/* /usr/local/bin/ \
  -        && rmdir docker \
  -        && rm docker.tgz \
  -        && docker -v
  +    && export DOCKER_VERSION=1.12.3 \
  +    && export DOCKER_SHA256=626601deb41d9706ac98da23f673af6c0d4631c4d194a677a9a1a07d7219fa0f \
  +    && apt-get update && apt-get install -y --no-install-recommends wget && rm -rf /var/lib/apt/lists/* \
  +    && wget -O docker.tgz "https://get.docker.com/builds/Linux/x86_64/docker-$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
   
  
positive.code:     && tini -h \
      && apt-get purge -y --auto-remove wget
  
  # gpg keys listed at https://github.com/nodejs/node
  RUN set -ex \
    && for key in \
      9554F04D7259F04124DE6B476D5A82AC7E37093B \
      94AE36675C464D64BAFA68DD7434390BDBE9B9C5 \
      0034A06D9D9B0064CE8ADF6BF1747F4AD2306D93 \
      FD3A5288F042B6850C66B31F09FE44734EB7990E \
      71DCFD284A79C3B38668286BC97EC7A07EDE3FC1 \
      DD8F2338BAE7501E3DD5AC78C273792F7D83545D \
      B9AE9905FFD7803F25714661B63B535A4C206CA9 \
      C4F0DFFF4E8C1A8236409D08E73BC641CC11F4C8 \
    ; do \
      gpg --keyserver ha.pool.sks-keyservers.net --recv-keys "$key"; \
    done
  
  ENV NODE_VERSION 0.12.15
  ENV NPM_VERSION 2.15.9
  
  RUN curl -SLO "https://nodejs.org/dist/v$NODE_VERSION/node-v$NODE_VERSION-linux-x64.tar.gz" \
      && curl -SLO "https://nodejs.org/dist/v$NODE_VERSION/SHASUMS256.txt.asc" \
      && gpg --verify SHASUMS256.txt.asc \
      && grep " node-v$NODE_VERSION-linux-x64.tar.gz\$" SHASUMS256.txt.asc | sha256sum -c - \
      && tar -xzf "node-v$NODE_VERSION-linux-x64.tar.gz" -C /usr/local --strip-components=1 \
      && rm "node-v$NODE_VERSION-linux-x64.tar.gz" SHASUMS256.txt.asc \
      && npm set progress=false \
      && npm install -g "npm@${NPM_VERSION}" \
      && npm cache clear
  
  ENV REDIS_VERSION 3.2.3
  ENV REDIS_DOWNLOAD_URL http://download.redis.io/releases/redis-3.2.3.tar.gz
  ENV REDIS_DOWNLOAD_SHA1 92d6d93ef2efc91e595c8bf578bf72baff397507
  
  RUN set -x \
      && mkdir -p /usr/src/redis \
      && curl -sSL "$REDIS_DOWNLOAD_URL" -o redis.tar.gz \
      && echo "$REDIS_DOWNLOAD_SHA1 *redis.tar.gz" | sha1sum -c - \
      && tar -xzf redis.tar.gz -C /usr/src/redis --strip-components=1 \
      && rm redis.tar.gz \
  
negative.code:     && apt-get purge -y --auto-remove wget
  
  # grab tini for signal processing and zombie killing
  RUN set -x \
      && export TINI_VERSION=0.13.1 \
      && 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/v$TINI_VERSION/tini" \
      && wget -O /usr/local/bin/tini.asc "https://github.com/krallin/tini/releases/download/v$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 \
  