install elasticsearch and kibana 6.5.1 on ubuntu

elk.sh

#!/bin/bash

#ONE LINE
#sudo wget -Nnv 'https://gist.githubusercontent.com/nsherron90/5afd897f881257cc282f4b35c622e826/raw/2072030410ea3d7956823e199ae4ef25b87079f9/elk.sh' && bash elk.sh && rm -f elk.sh

# Checking whether user has enough permission to run this script
sudo -n true
if [ $? -ne 0 ]
    then
        echo "This script requires user to have passwordless sudo access"
        exit
fi

dependency_check_deb() {
java -version
if [ $? -ne 0 ]
    then
        # Installing Java 8 if it's not installed
        sudo apt-get install openjdk-8-jre-headless -y
    # Checking if java installed is less than version 7. If yes, installing Java 7. As logstash & Elasticsearch require Java 7 or later.
    elif [ "`java -version 2> /tmp/version && awk '/version/ { gsub(/"/, "", $NF); print ( $NF < 1.8 ) ? "YES" : "NO" }' /tmp/version`" == "YES" ]
        then
            sudo apt-get install openjdk-8-jre-headless -y
fi
}

debian_elk() {
    # resynchronize the package index files from their sources.
    sudo apt-get update
    # Downloading debian package of elasticsearch
    wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-6.5.1.deb
    # Install debian package of elasticsearch
    sudo dpkg -i elasticsearch-6.5.1.deb
    # install kibana
    sudo apt-get install apt-transport-https
    wget https://artifacts.elastic.co/downloads/kibana/kibana-6.5.1-amd64.deb
    sudo dpkg -i kibana-6.5.1-amd64.deb
    # Starting The Services
    sudo systemctl restart elasticsearch
    sudo systemctl enable elasticsearch
    sudo systemctl restart kibana
    sudo systemctl enable kibana
}



# Installing ELK Stack
if [ "$(grep -Ei 'debian|buntu|mint' /etc/*release)" ]
    then
        echo " It's a Debian based system"
        dependency_check_deb
        debian_elk
        
        
elif [ "$(grep -Ei 'fedora|redhat|centos' /etc/*release)" ]
    then
        echo "It's a RedHat based system."
        dependency_check_rpm
        rpm_elk
else
    echo "This script doesn't support ELK installation on this OS."
fi