#!/bin/bash
# Name: report-hostgroups-empty.sh
# Description: Report Host Groups that don't have any members
# Last Modified: 2018-05-31
# Recent Changes:-Initial release
###############################################################################################

##### Customize These Variables #####
# IPA admin user
admin_user="admin"
##### End of Customize Variables #####

#=====================================
# Functions; Main starts after
#=====================================
function show_usage
{
  echo -e "\n==== Report: Empty Host Groups ===="
  echo -e "\nDescription: Report host groups that don't have any members."
  echo -e "\n--Usage--"
  echo -e "./report-hostgroups-empty.sh [OPTIONS]"
  echo -e "\n-OPTIONS-"
  echo -e "-h                    => Display usage."
  echo -e "-v                    => Verbose; extra status output."
  echo -e "\n--Other Requirements--"
  echo -e "-> FreeIPA admin access."
  echo -e
}

#=======================
# Get Script Arguments
#=======================
# Reset POSIX variable in case it has been used previously in this shell
OPTIND=1

# By default, do not output verbose
verbose_mode="no"

while getopts "hv" opt; do
  case "${opt}" in
    h) # -h (help) argument
      show_usage
      exit 0
    ;;
    v) # -v (verbose) argument
      verbose_mode="yes"
    ;;
    *) # invalid argument
      show_usage
      exit 0
    ;;
  esac
done

#===================
# Pre-checks: Make sure we have good options set
#===================
# See if we have a kerberos ticket, if not, prompt login
/usr/bin/klist -s
if [[ $? -ne 0 ]]; then
  echo ">>No kerberos ticket found for (${admin_user}), login as ${admin_user} now:"
  /usr/bin/kinit ${admin_user}
  echo
fi

#===================
# Main starts here
#===================
echo -e "======================================================"
echo -e "####========= Report: Empty Host Groups ==========####"
echo -e "======================================================"
echo
echo -e "This script will report all host groups that don't have any members."
if [[ ${verbose_mode} == "yes" ]]; then
  echo -e "Verbose: Yes"
else
  echo -e "Verbose: No"
fi
echo -e "=>Continue?[y/n]:\c"
read run_script

if [[ ${run_script} != "y" ]]; then
  echo -e "\n>>Will not run the script. Exiting..."
  exit 1
fi

# Get all host groups
echo -e ">> Getting all host groups."
all_hostgroups="$(ipa hostgroup-find --sizelimit=0 | awk '/Host-group/ {print $2}')"

# Initialize lists to nothing
hostgroup_nomembers=""
hostgroup_error=""

echo -e ">> Checking ($(echo ${all_hostgroups} | wc -w)) hostgroups for members\c"
if [[ ${verbose_mode} == "yes" ]]; then
  # Extra newline required if verbose messages (due to \c above)
  echo
fi

# Loop through all hostgroups, add ones with no members to the list
for hostgroup in ${all_hostgroups}; do

  if [[ ${verbose_mode} == "yes" ]]; then
    echo "--> Hostgroup: ${hostgroup}"
  else
    # Not verbose, output a single '.' per hostgroup search
    echo -e ".\c"
  fi

  ipa hostgroup-show ${hostgroup} | grep 'Member hosts' &> /dev/null
  return_code="$?"

  if [[ ${return_code} == "0" ]]; then
    # Members found
    if [[ ${verbose_mode} == "yes" ]]; then
      echo "---Members found."
    else
      # Do nothing ':' (equivalent to Python's 'pass')
      :
    fi

  elif [[ ${return_code} == "1" ]]; then
    # No members found
    if [[ ${verbose_mode} == "yes" ]]; then
      echo "---No members. (${hostgroup})"
    fi
    hostgroup_nomembers+="${hostgroup} "

  else
    # Some other error occurred
    if [[ ${verbose_mode} == "yes" ]]; then
      echo "---Warning: Some other error occurred. (${hostgroup})"
    fi
    hostgroup_error+="${hostgroup} "
  fi
done

if [[ ${verbose_mode} == "no" ]]; then
  # Extra space required if not verbose because of no newlines for '.' status output
  echo -e "[Done]"
fi

echo -e "\n-------------------------------------"
echo -e "---- Host Groups with No Members ----"
echo -e "-------------------------------------"

echo -e "\n>> Host Groups with No Members: $(echo ${hostgroup_nomembers} | wc -w)"
for hostgroup in ${hostgroup_nomembers}; do
  echo -e "${hostgroup}"
done

echo -e "\n>> Host Groups that had some type of grep search error: $(echo ${hostgroup_error} | wc -w)"
for hostgroup in ${hostgroup_error}; do
  echo -e "${hostgroup}"
done

echo -e "\n=========================================="
echo -e "=- Report: Empty Host Groups Completed. -="
echo -e "=========================================="