#!/bin/bash

# usage: curl https://raw.githubusercontent.com/SunnyBingoMe/install-hadoop/master/setup-hadoop | bash
# Note: if wanted, create_hadoop_user will ask for a new pwd for the user: ${HDUSER}.
# Note: to start-dfs.sh, we need to `su ${HDUSER}` first.

HDUSER=ubuntu # change to your desired username

# Function for asking to proceed
confirm () {
  read -r -p "${1:-Are you sure? [y/N]} " response
  case $response in
    [yY][eE][sS]|[yY])
      true
      ;;
     *)
      false
      ;;
  esac
}

function update_apt_repo  {
  sudo add-apt-repository ppa:webupd8team/java
  sudo apt-get update 
}

function install_java {
  sudo apt-get install -y oracle-java8-installer
  sudo apt-get install -y oracle-java8-set-default
}

function install_open_java {
  sudo apt-get update && \
  sudo apt-get install -y openjdk-8-jdk && \
  sudo ln -s /usr/lib/jvm/java-8-openjdk-amd64 /opt/jdk && \
  echo "JAVA_HOME='/opt/jdk'" | sudo tee -a /etc/environment && \
  source /etc/environment && \
  echo $JAVA_HOME
}

function create_hadoop_user {
  sudo useradd -m ${HDUSER}
  sudo adduser ${HDUSER} sudo
  sudo chsh -s /bin/bash ${HDUSER}
  #sudo passwd ${HDUSER}
}

function install_hadoop {
  sudo mkdir -p /usr/local/hadoop/
  cd /usr/local/hadoop
  sudo curl http://archive.apache.org/dist/hadoop/common/hadoop-2.7.2/hadoop-2.7.2.tar.gz | sudo tar xz 
  sudo chown -R ${HDUSER}:${HDUSER} /usr/local/hadoop
}

function setup_profile {
  local file=/etc/profile.d/hadoop-init.sh
  local tempfile=/tmp/hadoop_setup_sdfds.sh
  sudo mkdir -p /tmp/hadoop
  sudo chown -R ${HDUSER}:${HDUSER} /tmp/hadoop
  export HADOOP_HOME=/usr/local/hadoop/hadoop-2.7.2
  export PATH=$PATH:$HADOOP_HOME/bin:$HADOOP_HOME/sbin
  cat >> $tempfile  <<EOT
export HADOOP_HOME=/usr/local/hadoop/hadoop-2.7.2
export PATH=\$PATH:\$HADOOP_HOME/bin:\$HADOOP_HOME/sbin
EOT
  tempfile=/tmp/hadoop_setup_sdfds.sh
  chmod +x $tempfile
  sudo chown root $tempfile
  sudo mv $tempfile $file
}

function setup_core_xml {
  export HADOOP_HOME=/usr/local/hadoop/hadoop-2.7.2
  local tmpfile=/tmp/hadoop_fafsa.xml
  local file=$HADOOP_HOME/etc/hadoop/core-site.xml
  sudo rm -rf $file
  cat >> $tmpfile <<EOF
<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<configuration>
<property>
    <name>hadoop.tmp.dir</name>
    <value>/tmp/hadooop</value>
    <description>optional, temporary directories.</description>
</property>
<property>
    <name>fs.default.name</name>
    <value>hdfs://localhost:9000</value>
    <description>A URI whose scheme and authority determine the FileSystem implementation. </description>
</property>
</configuration>
EOF
  tmpfile=/tmp/hadoop_fafsa.xml
  sudo chown root $tmpfile
  sudo mv $tmpfile $file
}

function setup_mapred_xml {
  export HADOOP_HOME=/usr/local/hadoop/hadoop-2.7.2
  local tmpfile=/tmp/hadoop_mapred.xml
  local file=$HADOOP_HOME/etc/hadoop/mapred-site.xml
  sudo rm -rf $file
  cat >> $tmpfile <<EOT
<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<configuration>
<property>
  <name>mapred.job.tracker</name>
  <value>localhost:54311</value>
  <description>The tracker of MapReduce</description>
</property>
</configuration>
EOT
  tmpfile=/tmp/hadoop_mapred.xml
  sudo chown root $tmpfile
  sudo mv $tmpfile $file
}

function setup_hdfs_xml {
  export HADOOP_HOME=/usr/local/hadoop/hadoop-2.7.2
  local tmpfile=/tmp/hadoop_hdfs.xml
  local file=$HADOOP_HOME/etc/hadoop/hdfs-site.xml
  sudo rm -rf $file
  cat >> $tmpfile <<EOF
<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<configuration>
<property>
  <name>dfs.replication</name>
  <value>1</value>
  <description>Number of replication of hdfs</description>
</property>
</configuration>
EOF
  tmpfile=/tmp/hadoop_hdfs.xml
  sudo chown root $tmpfile
  sudo mv $tmpfile $file
}

function setup_environment {
  export HADOOP_HOME=/usr/local/hadoop/hadoop-2.7.2
  sudo sed -i -- 's/JAVA_HOME=\${JAVA_HOME}/JAVA_HOME=\$(readlink -f \/usr\/bin\/java | sed "s:bin\/java::")/' $HADOOP_HOME/etc/hadoop/hadoop-env.sh
  setup_profile
  setup_core_xml
  setup_mapred_xml
  setup_hdfs_xml
  sudo chown -R ${HDUSER}:${HDUSER} $HADOOP_HOME
}

if [ ! $HDUSER == $USER ]; then 
	create_hadoop_user
	install_open_java
	install_hadoop
	echo "================== WARNING ! =================="
	echo "Installer '$USER' is NOT hadoop user '$HDUSER', plz run 'setup_environment' as the hadoop user '$HDUSER' after this script."
	echo "================== WARNING ! =================="
else
	install_open_java
	install_hadoop
	setup_environment
fi