Ansible module to list groups in inventory.

#!/bin/bash
#5 minutes Ansible module to list groups in inventory :D
#You can see outupt of script like "JSON Pretty Print" outside Ansible by using:
#./listgroups | python -m json.tool

inventory_file=$(awk '/^hostfile/{print $3}' /etc/ansible/ansible.cfg)
groups_array=($(awk 'BEGIN {ORS=" "}; /^\[/{gsub("[\[\]]",""); print}' $inventory_file))

init_array_for_json () {
for group in ${groups_array[@]}; do
  printf "\"$group\",";
done
}

printf "{\"Inventory Groups\": [$(init_array_for_json)]}" | sed 's/,]/]/g'