I want to replace configuration file contents using Propellor, but some configuration files are long so I want to keep them outside config.hs and without having to use quotation. I came up with this:

```
{-# LANGUAGE TemplateHaskell #-}
module Utility.Embed where

import Language.Haskell.TH
import qualified Data.FileEmbed as FE

sourceFile :: FilePath -> Q Exp
sourceFile path = return . AppE (VarE 'lines) =<< FE.embedStringFile path
```

Which can be used like this:

```
standardSystem :: HostName -> Host
standardSystem hn = host hn
                    & Apt.installed ["heimdal-clients"]
                    & "/etc/krb5.conf" `File.hasContent`
                          $(sourceFile "files/etc/krb5.conf")
```

What do you think, is this the right approach or should I just read source files with the IO monad?
