Embedding LuaRocks in an application

You can use LuaRocks bundled inside your application, for example, to install application-specific extension modules. Packaging those extensions or plugins as rocks reduces maintenance overhead and allows the user to perform updates.

In this scenario, it is not desirable to have the application-specific LuaRocks and any other copy of LuaRocks installed by the user (or other applications!) to interfere with each other. For this reason, the configure script allows hardcoding the location of a configuration file. For example, the compilation process of a package bundling LuaRocks could do something like this:

export PREFIX=$HOME/my-app/
./configure --prefix=$PREFIX --sysconfdir=$PREFIX/luarocks --force-config

The copy of LuaRocks installed in $HOME/my-app/ will ignore customization schemes such as the $LUAROCKS_CONFIG environment variable and will only use $HOME/my-app/luarocks/config-5.x.lua.

An interesting option in those cases is for the application to provide in its configuration file an URL for their own rocks repository, so they can have control over updates to be performed. Continuing the previous example, the config-5.x.lua file could contain something like this:

 rocks_servers = {
    "http://www.example.com/my-app-plugins/rocks/"
 }

This way the bundled copy of LuaRocks will download rocks from your app's plugins and not the https://luarocks.org server (note that the user would still be able to override it explicitly using the --server flag).