Advanced Modulefile using lua syntax

example_modulefile.lua

--[[
## Modulefile in lua syntax
## Author: Samir Amin

## Read about Lmod
## https://lmod.readthedocs.io/en/latest/015_writing_modules.html
## https://lmod.readthedocs.io/en/latest/050_lua_modulefiles.html
## https://lmod.readthedocs.io/en/latest/020_advanced.html
--]]

--################################ INTERNAL VARS #################################
--Module Name and Version are parsed by Lmod from dir/version string in module path
local pkgName = myModuleName()
local version = myModuleVersion()
local pkgNameVer = myModuleFullName()

local approot = "/projects/verhaak-lab/amins/sumnerenv_os7/opt/apps"
local appbase = "java/jdk"
local pkgdir = pathJoin(approot,appbase,version)
local pkgbin = pathJoin(pkgdir,"bin")

local lib1 = pathJoin(pkgdir,"lib")
local lib2 = pathJoin(pkgdir,"lib/server")
local java_ldpath = lib1 .. ":" .. lib2

local default_java_home = os.getenv("JAVA_HOME")
local default_java_ldpath = os.getenv("JAVA_LD_LIBRARY_PATH")

--################################# MODULE INFO ##################################
whatis("Name: ".. pkgName)
whatis("Version: " .. version)

--################################## ENV SETUP ###################################
prepend_path("PATH", pkgbin)
prepend_path("JAVA_LD_LIBRARY_PATH", java_ldpath)
pushenv("JAVA_HOME", pkgdir)

--################################# MODULE LOAD ##################################
help(
"Loads " .. pkgNameVer .. '\nCheck env change, if any by\nmodule show ' .. pkgNameVer
)

if (mode() == "load") then
  LmodMessage("## INFO ##\nLoading " .. pkgName .. version .. "from " .. pkgdir)
  LmodMessage("\n## WARN ##\nChanged some default JAVA vars\nJAVA_HOME from " .. default_java_home .. " to " .. pkgdir .. "\nJAVA_LD_LIBRARY_PATH from " .. default_java_ldpath .. " to " .. java_ldpath)
end

if (mode() == "unload") then
  LmodMessage("## INFO ##\nUnloading " .. pkgName .. version .. "from " .. pkgdir)
  LmodMessage("\n## WARN ##\nResetting JAVA vars to defaults\nJAVA_HOME from " .. pkgdir .. " to " .. default_java_home .. "\nJAVA_LD_LIBRARY_PATH from " .. java_ldpath .. " to " .. default_java_ldpath)
end

--## END ##