Shell Script to install, uninstall ChefDK

operate-chefdk.sh

#!/bin/bash

# =============================================
# Installs and Uninstalls the ChefDK
# =============================================
#
#    -i		Install ChefDK
#    -u		Uninstall ChefDK
#    -c		Verify ChefDK
#    -h		Show Help
#
# ==============================================
# Description:
#
#   Tested and Used in elementary OS, Ubuntu 16.04.
#
#   Tested in BASH shell version 4.3.46
#
#   Not backward comaptible with older bash versions,
#   since the usage of Associate Array in the script,
#   which is added in 4.0 version
#
#   Feel free to Extend, Use, Test in other OS
#   and post it
#
# ==============================================

# Variable Declarations
kernel_supported="linux"
architecture_supported="x86_64"
os_supported=( "debian" "ubuntu" "redhat" "suse" )
declare -A elementary_ubuntu_version=( ["0.1"]="10.10" ["0.2"]="12.04" ["0.3"]="14.04" ["0.4"]="16.04" )
declare -A chefdk_os_translations=( ["ubuntu"]="ubuntu" ["debian"]="debian" ["suse"]="sles" ["rhel"]="el" )
chefdk_url_part1="https://packages.chef.io/files/stable/chefdk/1.5.0/:distro/:version/"
declare -A os_packages=( ["ubuntu"]="deb" ["debian"]="deb" ["suse"]="rpm" ["rhel"]="rpm" )
declare -A chefdk_package_ext=( ["deb"]="chefdk_1.5.0-1_amd64.deb" ["rpm"]="chefdk-1.5.0-1.:distro:version.x86_64.rpm" )

# Function which checks for the root user execution
root_checker() {
  # Checks if the script is ran by the root user
  if [ $EUID -ne 0 ]
  then
    echo -e "\nPlease run as root user!!!!!!!!!!!!!!!!!!!!!!!\n"
    exit 1
  fi
}

# Checks for the kernel support
kernel_checker() {
  kernel_name=`uname -s | tr "[:upper:]" "[:lower:]"`
  if [ ! -z ${kernel_name+x} ]
  then
    if [ $kernel_name != $kernel_supported ]
    then
      echo -e "\nPlease extend the functionality to support your kernel. Current support: linux\n"
      exit 1
    fi
  else
    echo -e "\nPlease extend the functionality to support your kernel. Current support: linux\n"
    exit 1
  fi
  unset kernel_name
}

# Checks for the processor's architecture
architecture_checker() {
  architecture=`uname -p`
  if [ ! -z ${architecture+x} ]
  then
    if [ $architecture != $architecture_supported ]
    then
      echo -e "\nSupports only x86_64 architecture\n"
      exit 1
    fi
  else
    echo -e "\nSupports only x86_64 architecture\n"
    exit 1
  fi
  unset architecture
}

# Gets the distribution and version of the os
distro_checker() {
  if [ -f /etc/lsb-release ]
  then
    distro=`lsb_release -si | tr "[:upper:]" "[:lower:]"`
    version=`lsb_release -sr | egrep -o "[0-9]+.[0-9]+"`
  elif [ -f /etc/redhat-release ]
  then
    distro="rhel"
    version=`cat /etc/redhat-release | sed s/.*release\ // | sed s/\ .*// | cut -d. -f1`
  elif [ -f /etc/SuSE-release ]
  then
    distro="suse"
    version=`cat /etc/SuSE-release | tr "\n" ' ' | sed s/.*=\ // | cut -d. -f1`
  elif [ -f /etc/os-release ]
  then
    distro=`cat /etc/os-release | grep "^ID=" | egrep -o "[a-zA-Z]+$" | tr "[:upper:]" "[:lower:]"`
    version=`cat /etc/os-release | grep "^VERSION_ID=" | egrep -o "[0-9]+(\.[0-9]+)?" | head -1`
  else
    distro=`hostnamectl | grep Operating | cut -d: -f2 | egrep -o "[a-zA-Z]+" | head -1 | tr "[:upper:]" "[:lower:]"`
    version=`hostnamectl | grep Operating | cut -d: -f2 | egrep -o "[0-9]+(\.[0-9]+)?" | head -1`
  fi

  # Calls the functions which maps to base distro
  ubuntu_based_distro_checker
}

# Checks if the distro is based on ubuntu
ubuntu_based_distro_checker() {
  # Condition for Elementary OS
  if [ $distro == "elementary" ]
  then
    distro="ubuntu"
    # Sets the version related to ubuntu
    for key in ${!elementary_ubuntu_version[@]}
    do
      if [ $key == $version ]
      then
        version=${elementary_ubuntu_version[$key]}
        break
      fi
    done
  fi
  unset key
}

# Contains all the package manager cache related operations
package_manager_cache() {
  case $distro in
    debian|ubuntu)
      # Updates the apt cache
      apt update
    ;;
  esac
}

# Prepares the ChefDK URL based on the system informations
chefdk_url_preparer() {
  # Gets the package related to the distro
  local package=${os_packages[$distro]}
  # Gets the ChefDK extension related to that package
  local chefdk_url_ext=${chefdk_package_ext[$package]}
  # Translates the os name to chef dk supported name
  local chefdk_os_name=${chefdk_os_translations[$distro]}
  chefdk_url=`echo "${chefdk_url_part1}${chefdk_url_ext}" | sed s/:distro/$chefdk_os_name/g | sed s/:version/$version/g `
}

# Downloads and Installs the ChefDK package
chefdk_installer() {
  local chefdk_package_name="chefdk"
  local package_name="/tmp/chefdk.${os_packages[$distro]}"
  echo -e "\nDownloading ChefDK ....................\n ${chefdk_url} \n\n"
  # Downloads the ChefDK package
  curl -o $package_name $chefdk_url
  # Checks for the Successful download
  if [ $? -ne 0 ]
  then
    echo -e "\nChefDK download failed......\n"
    exit 1
  fi
  # Gets the SHA1 checksum of the package
  sha1_hash=$(curl -I $chefdk_url | grep -i sha1 | cut -d: -f2 | egrep -o "[0-9a-zA-Z]+")
  # Checks for the Successful download
  if [ $? -ne 0 ]
  then
    echo -e "\nChefDK download failed......\n"
    exit 1
  fi
  # Checks the sha1 checksum
  echo $sha1_hash $package_name | sha1sum -c -
  # Checks for the SHA1 hash
  if [ $? -ne 0 ]
  then
    echo -e "\nChefDK download failed......\n"
    exit 1
  fi 
  echo -e "\nInstalling ChefDK ....................\n"
  case ${os_packages[$distro]} in
    deb) dpkg --list | grep -i ${chefdk_package_name}
         # Checks for the availability of chefdk package
         if [ $? -eq 0 ]
         then
           echo -e "\nChefDK is already installed......\n"
           exit 1
         fi
         dpkg -i $package_name
         echo -e "\nChefDK is successfully installed\n"
    ;;
    rpm) rpm -qa | grep -i ${chefdk_package_name}
         # Checks for the availability of chefdk package
         if [ $? -eq 0 ]
         then
           echo -e "\nChefDK is already installed......\n"
           exit 1
         fi
         rpm -ivh $package_name
         echo -e "\nChefDK is successfully installed\n"
    ;;
    *)  echo -e "\nYour Operating system is not Supported!!!\n"
        exit 1
    ;;
  esac
}

# Checks for the availability of ChefDK package
chefdk_availability_checker() {
  local chefdk_package_name="chefdk"
  case ${os_packages[$distro]} in
    deb) dpkg --list | grep -i ${chefdk_package_name} > /dev/null
         # Checks for the availability of chefdk package
         if [ $? -eq 0 ]
         then
           echo -e "\nChefDK is already installed......\n"
           exit 1
         fi
    ;;
    rpm) rpm -qa | grep -i ${chefdk_package_name} > /dev/null
         # Checks for the availability of chefdk package
         if [ $? -eq 0 ]
         then
           echo -e "\nChefDK is already installed......\n"
           exit 1
         fi
    ;;
    *)  echo -e "\nYour Operating system is not Supported!!!\n"
        exit 1
    ;;
  esac
}

# Checks whether ChefDK installed successfully or not
chefdk_installation_checker() {
  # Verifies Chef
  chef verify 2>/dev/null
  if [ $? -eq 0 ]
  then
    echo -e "\nChefDK is installed successfully!!!!!!!!!!!!!!!\n"
  else
    echo -e "\nChefDK is not installed or configured properly......\n"
    exit 1
  fi
}

# Uninstalls the ChefDK package
chefdk_uninstaller() {
  local chefdk_package_name="chefdk"
  echo -e "\nUninstalling ChefDK ....................\n"
  case ${os_packages[$distro]} in
    deb) dpkg --list | grep -i ${chefdk_package_name} > /dev/null
         # Checks for the availability of chefdk package
         if [ $? -ne 0 ]
         then
           echo -e "\nChefDK not found......\n"
           exit 1
         fi
         dpkg -r ${chefdk_package_name}
         echo -e "\nChefDK is successfully uninstalled\n"
    ;;
    rpm) rpm -qa | grep -i ${chefdk_package_name} > /dev/null
         # Checks for the availability of chefdk package
         if [ $? -ne 0 ]
         then
           echo -e "\nChefDK not found......\n"
           exit 1
         fi
         rpm -evv ${chefdk_package_name}
         echo -e "\nChefDK is successfully uninstalled\n"
    ;;
    *)  echo -e "\nYour Operating system is not Supported!!!\n"
        exit 1
    ;;
  esac
}

# Installs CURL utility
curl_installer() {
  echo -e "\nInstalling CURL ....................\n"
  case $distro in
    debian|ubuntu) apt install -y curl
         echo -e "\nCURL is successfully installed\n"
    ;;
    rhel) yum -y install curl
         echo -e "\nCURL is successfully installed\n"
    ;;
    suse) zypper --non-interactive install curl
         echo -e "\nCURL is successfully installed\n"
    ;;
    *)  echo -e "\nYour Operating system is not Supported!!!\n"
        exit 1
    ;;
  esac
}

# Parses the Input options
input_options_parser() {
  # Available Input options
  declare -A input_options=( ["-i"]="install" ["-u"]="uninstall" ["-c"]="check" )
  local input_options_pattern="<-i><-u><-c>"
  local input_options_help_pattern="<-h>"
  # sets the help test
  read -r -d '' help_text <<EndOfHelp
    \n
    \t  -i \t Install ChefDK \n
    \t  -u \t Uninstall ChefDK \n
    \t  -c \t Verify ChefDK \n
    \t  -h \t Show Help \n
    \n
EndOfHelp
  # Error options output
  local error_options_text="\n\tUse -h for help\n"
  # Error options flag
  local error_options_flag=0
  # Help options flag
  local help_options_flag=0
  local options_set_flag=0

  # Checks for the number of options
  if [ $# -eq 0 ]
  then
    error_options_flag=1
   else
    # Loops through the Input Options
    for option in $@
    do
      # Prepares the pattern from the input options
      option_pattern=$( echo "<${option}>" | sed "s/\-/\\\\-/g" )
      # Checks for the help option
      echo $input_options_help_pattern | grep $option_pattern >/dev/null
      if [ $? -eq 0 ]
      then
        help_options_flag=1
        break
      fi
      # Checks for the other options
      echo $input_options_pattern | grep $option_pattern >/dev/null
      if [ $? -ne 0 ]
      then
        error_options_flag=1
      else
        if [ $options_set_flag -eq 0 ]
        then
          chefdk_operation=${input_options[$option]}
          options_set_flag=1
        else
          error_options_flag=1
        fi
      fi
    done
  fi

  # Prints the help text
  if [ $help_options_flag -eq 1 ]
  then
    echo -e $help_text
    exit 0
  fi
  # Prints the Error text
  if [ $error_options_flag -eq 1 ]
  then
    echo -e $error_options_text
    exit 1
  fi

  unset help_text
  unset input_options
}

# Gets all the details related to system
system_details() {
  # Checks for the processor architecture
  architecture_checker
  # Checks for the kernel support
  kernel_checker
  # Checks the distro and its version
  distro_checker
}

# Install some necessary tools
utilities_installer() {
  # Functionalities related to Package Manager
  package_manager_cache
  # Installs CURL
  curl_installer
}

# Operations related to ChefDK
chefdk_stuffs() {
  case $chefdk_operation in
    install)
      # Checks for the availability of ChefDK package
      chefdk_availability_checker
      # Installs necessary utilities
      utilities_installer
      # Functionalities related to Package Manager
      package_manager_cache
      # Prepares the url for downloading ChefDk
      chefdk_url_preparer
      # Installs ChefDK
      chefdk_installer
      # Verfies ChefDK installation
      chefdk_installation_checker
    ;;
    uninstall)
      # Uninstalls the ChefDK package
      chefdk_uninstaller
    ;;
    check)
      # Verifies the ChefDK
      chefdk_installation_checker
    ;;
    *)
      echo -e "\nInvalid option!!!!!!!\n"
      exit 1
    ;;
  esac
}

# Main execution context
main() {
  # Parses the input options
  input_options_parser $@
  # Checks for the execution by root user
  root_checker
  # Gets the System related details
  system_details
  # ChefDK related stuffs execution
  chefdk_stuffs
}

# Calls the main function
main $@

# Exits with code 0 - success
exit 0