# Base image: Debian-12 (slim)
FROM debian:12-slim

# Update local package index, upgrade packages and install required packages. 
RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
	openjdk-17-jdk \
	net-tools \
	curl \
	gnupg \
  netcat-openbsd \
	&& rm -rf /var/lib/apt/lists/*
      
# Set Java env (currently using Java 17)
ENV JAVA_HOME=/usr/lib/jvm/java-17-openjdk-amd64/

# Download Hadoop Keys
RUN curl -O https://dist.apache.org/repos/dist/release/hadoop/common/KEYS

# Import keys
RUN gpg --import KEYS

# Set hadoop version & URL (currently using Hadoop 3.4.1)
ENV HADOOP_VERSION=3.4.1
ENV HADOOP_URL=https://www.apache.org/dist/hadoop/common/hadoop-$HADOOP_VERSION/hadoop-$HADOOP_VERSION.tar.gz

# Download hadoop and signature, verify with gpg, extract hadoop-ver.tar.hz into /opt and remove hadoop-ver.tar.gz
RUN set -x \
	&& curl -fSL "$HADOOP_URL" -o /tmp/hadoop.tar.gz \
	&& curl -fSL "$HADOOP_URL.asc" -o /tmp/hadoop.tar.gz.asc \
	&& gpg --verify /tmp/hadoop.tar.gz.asc \
	&& tar -xvf /tmp/hadoop.tar.gz -C /opt/ \
	&& rm /tmp/hadoop.tar.gz*

# Establish symobolic link in /etc/hadoop for /opt/hadoop-$HADOOP_VERSION/etc/hadoop
RUN ln -s /opt/hadoop-$HADOOP_VERSION/etc/hadoop /etc/hadoop

# Make logs dir and data dir
RUN mkdir -p /opt/hadoop-$HADOOP_VERSION/logs /hadoop-data /hadoop /hadoop/dfs /hadoop/yarn /hadoop/dfs/data /hadoop/dfs/name

# Set env
ENV HADOOP_HOME=/opt/hadoop-$HADOOP_VERSION
ENV HADOOP_CONF_DIR=/etc/hadoop
ENV HADOOP_OPTS="--add-opens java.base/java.lang=ALL-UNNAMED"
ENV MULTIHOMED_NETWORK=1
ENV USER=hdoop
ENV PATH $HADOOP_HOME/bin/:$PATH

# Ensure required config files exist
# RUN mkdir -p /etc/hadoop && \
#     echo "<configuration></configuration>" > /etc/hadoop/core-site.xml && \
#     echo "<configuration></configuration>" > /etc/hadoop/hdfs-site.xml && \
#     echo "<configuration></configuration>" > /etc/hadoop/yarn-site.xml && \
#     echo "<configuration></configuration>" > /etc/hadoop/mapred-site.xml && \
#     echo "<configuration></configuration>" > /etc/hadoop/httpfs-site.xml && \
#     echo "<configuration></configuration>" > /etc/hadoop/kms-site.xml

# Create non-root user
RUN useradd -m -s /bin/bash hdoop

# Copy entrypoint.sh to container
ADD entrypoint.sh /entrypoint.sh

# Set ownership for Hadoop dirs
RUN chown -R hdoop:hdoop /opt/hadoop-$HADOOP_VERSION /etc/hadoop /hadoop-data /hadoop

# Make entrypoint.sh executable
RUN chmod a+x /entrypoint.sh

USER hdoop

# Specify entrypoint
ENTRYPOINT ["/entrypoint.sh"]