anchor.diff:      TERM=xterm
   
   RUN set -x \
  +# Install prerequisites
   	&& apt-get update \
   	&& DEBIAN_FRONTEND=noninteractive apt-get install --no-install-recommends --no-install-suggests -y \
         apt-transport-https \
  
positive.code:       apt-utils \
        pwgen \
        gnupg && \
  	GPGKEY=A3C4F0F979CAA22CDBA8F512EE8CBC9E886DDD89; \
  	found=''; \
  	for server in \
  
negative.code: 		APT_KEY_DONT_WARN_ON_DANGEROUS_USAGE="True" apt-key adv --keyserver "$server" --keyserver-options timeout=10 --recv-keys "$GPGKEY" && found=yes && break; \
  	done; \
  	test -z "$found" && echo >&2 "error: failed to fetch GPG key $GPGKEY" && exit 1; \
    apt-get remove --purge --auto-remove -y gnupg && apt-get clean && rm -rf /var/lib/apt/lists/* && \
    \
    echo "deb https://deb.torproject.org/torproject.org stretch main"   >  /etc/apt/sources.list.d/tor-apt-sources.list && \
    echo "deb http://deb.torproject.org/torproject.org obfs4proxy main" >> /etc/apt/sources.list.d/tor-apt-sources.list && \
  # Install tor and obfs4proxy & backup torrc
    apt-get update && \
    DEBIAN_FRONTEND=noninteractive apt-get install --no-install-recommends --no-install-suggests -y \
      tor \
      deb.torproject.org-keyring \
      obfs4proxy && \
    mv -v /etc/tor/torrc /etc/tor/torrc.default && \
    apt-get clean && rm -rf /var/lib/apt/lists/*
  
  # Copy Tor configuration file
  COPY ./config/torrc /etc/tor/torrc
  