anchor.diff:      ; do \
         gpg --keyserver ha.pool.sks-keyservers.net --recv-keys "$key"; \
       done \
  -    && apt-get update && apt-get install -y --no-install-recommends wget && rm -rf /var/lib/apt/lists/* \
  +    && apt-get update && apt-get install -y --no-install-recommends gnupg gnupg2 wget && rm -rf /var/lib/apt/lists/* \
       && wget --no-verbose "https://nodejs.org/dist/v$NODE_VERSION/node-v$NODE_VERSION-linux-x64.tar.gz" \
       && wget --no-verbose "https://nodejs.org/dist/v$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 -r "$GNUPGHOME" "node-v$NODE_VERSION-linux-x64.tar.gz" SHASUMS256.txt.asc \
  -    && apt-get purge -y --auto-remove wget \
  +    && apt-get purge -y --auto-remove gnupg gnupg2 wget \
       && npm install -g yarn@$YARN_VERSION \
       && npm cache clear --force
   
  
positive.code:     && rm -r "$GNUPGHOME" /usr/local/bin/tini.asc \
      && chmod +x /usr/local/bin/tini \
      && tini -h \
      && apt-get purge -y --auto-remove wget
  
  # gpg keys listed at https://github.com/nodejs/node
  RUN set -x \
  
negative.code:     && rm -r "$GNUPGHOME" /usr/local/bin/gosu.asc \
      && chmod +x /usr/local/bin/gosu \
      && gosu nobody true \
      && apt-get purge -y --auto-remove gnupg gnupg2 wget
  
  # grab tini for signal processing and zombie killing
  RUN set -x \
      && export TINI_VERSION=0.15.0 \
      && apt-get update && apt-get install -y --no-install-recommends gnupg gnupg2 wget && rm -rf /var/lib/apt/lists/* \
      && wget --no-verbose -O /usr/local/bin/tini "https://github.com/krallin/tini/releases/download/v$TINI_VERSION/tini" \
      && wget --no-verbose -O /usr/local/bin/tini.asc "https://github.com/krallin/tini/releases/download/v$TINI_VERSION/tini.asc" \
      && export GNUPGHOME="$(mktemp -d)" \
  