anchor.diff:  
   # install dev tools
   RUN set -x \
  -    && apt-get update && apt-get install -y \
  +    && apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y \
       curl tar sudo openssh-server openssh-client rsync unzip krb5-user
   
   # Kerberos client
  
positive.code: #
  # Creates multi-node, kerberized Hadoop cluster on Docker
  
  FROM sequenceiq/pam:ubuntu-14.04
  
  RUN set -x \
      && addgroup hadoop \
  
negative.code:     && ssh-keygen -q -N "" -t rsa -f /etc/ssh/ssh_host_rsa_key \
      && ssh-keygen -q -N "" -t rsa -f /root/.ssh/id_rsa \
      && cp /root/.ssh/id_rsa.pub /root/.ssh/authorized_keys
  
  RUN sed -i 's/^#crypto.policy=unlimited/crypto.policy=unlimited/' $JAVA_HOME/jre/lib/security/java.security
  
  