resolved packages in rego policy directory, filters based on a regex input

get_rego_namespaces.bash

# get_rego_namespaces
# ====================
#
# Summary: Resolves the package names in your rego policies against a regex lookup
#
# Usage: get_rego_namespaces ${regex}
#
# Options:
#   <regex>     Regex pattern matching package name
# Globals:
#   none
# Returns:
#   string - list of --namespaces {which-matched-regex}
get_rego_namespaces() {
  local regex="${1:-.*}"
  declare -a namespaces

  # shellcheck disable=SC2038
  for file in $(find policy/* -name "*.rego" -type f | xargs); do
    read -r line < "${file}"

    local current="$(echo ${line/package/} | xargs)"
    if [[ "${current}" =~ ${regex} ]]; then
      if [[ ! "${namespaces[*]}" =~ ${current} ]]; then
        namespaces+=("--namespace ${current}")
      fi
    fi
  done

  echo "${namespaces[*]}"
}