How to enforce group in lmod lua

enforce_group.lua

-- Function to check if a user is in a given group
-- Hardcoded to allow group root. Can also add sudo
-- if needed and any other group to always allow
local function enforce_group(group)
    local user = subprocess("whoami")
    local command = "id -nG " .. user
    local result = subprocess(command)
    if result:find("root") then return end
    if not result:find(group) then
       LmodError("Access to this module is denied.")
    end
end

-- Usage
enforce_group("a_group_to_enforce")