anchor.diff:  ONBUILD COPY hadoop/conf/ ${HADOOP_CONF_DIR}/
   ONBUILD COPY dags/ ${AIRFLOW_DAG}
   
  -
   COPY install_spark_packages.py ${AIRFLOW_HOME}/install_spark_packages.py
   ONBUILD RUN gosu "${USER}" python install_spark_packages.py
   
  
positive.code: # Install gosu
  ARG GOSU_VERSION=1.10
  RUN set -x \
      && apt-get update && apt-get install -y --no-install-recommends ca-certificates 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" \
      && export GNUPGHOME="$(mktemp -d)" \
  
negative.code: # Setup airflow
  RUN set -ex \
      && apt-get update \
      && apt-get install --no-install-recommends -y vim-tiny libsasl2-dev libffi-dev \
      && rm -rf /var/lib/apt/lists/* \
      && pip install --no-cache-dir "apache-airflow[devel_hadoop, crypto]==1.8.1" psycopg2
  
  