[chef] Re: RE: Re: library gem dependencies

[Greg Symons < >]

Libraries are loaded before recipes are compiled, so you can't install 
gems for direct use by libraries. What you can do, though, is install 
the gems using chef_gem the way you normally would, and then have a 
load_dependencies method in your library that requires in all the gems 
you needed (warning, untested code follows):

module Cookbook
   class MyLibrary
   class << self
       def load_dependencies
           require 'my_gem'
       end

       def foo_uses_my_gem bar
           MyLibrary.load_dependencies
           MyGem::do_the_thing_with_the_bar bar
       end
   end
   end
end

And in your recipe you can do this:

chef_gem 'my_gem'
MyLibrary.foo_users_my_gem node[:cookbook][:bar]

Greg
On Tue 05 Mar 2013 04:10:00 AM CST, Philippe Bérard wrote:
> I'm afraid to say that it works in a recipe.
>
> Regards,
>
> -- Philippe Bérard
>
>
> -----Message d'origine-----
> De : Sam Darwin 
> [mailto:
>  
> Envoyé : mardi 5 mars 2013 10:38
> À : 
>
>  ;
>  Philippe Bérard
> Objet : [chef] Re: library gem dependencies
>
> In a libraries file, not a recipe file.
>
> On Tue, Mar 5, 2013 at 11:32 AM, Philippe Bérard
> <
>  >
>  wrote:
> > I don't know if I do it correctly, but here's my answer.
> >
> > Just do it that way :
> > chef_gem 'treetop'
> > require 'treetop'
> >
> > It will be installed at the right time before being loaded by the recipe.
> >
> > Regards,
> >
> > -- Philippe Bérard
> >
> > -----Message d'origine-----
> > De : Sam Darwin 
> > [mailto:
> >  
> > Envoyé : mardi 5 mars 2013 10:29
> > À : 
> >
> >  
> > Objet : [chef] library gem dependencies
> >
> >
> > Let's say a cookbook library requires a gem called treetop (it could
> > be any gem actually), and so it has this line:
> >
> > require 'treetop'
> >
> > I want to get that installed as a pre-requisite, and so I add this
> > code into the default recipe:
> >
> > r = chef_gem "treetop" do
> >    action :nothing
> > end
> > r.run_action(:install)
> >
> > But apparently it won't get called soon enough.    The library has errors
> > about
> > treetop missing.
> >
> > As another attempt, I create a different cookbook called
> > pre-requisites.  I add the code "r = chef_gem "treetop" do"  into the
> > pre-requisites cookbook, and
> > have that as a cookbook dependency.   Nope.   This also doesn't get called
> > soon
> > enough.   treetop is missing.     Installing the treetop gem by hand will
> > fix
> > it.
> >
> > The issue seems to be with a library and not with a recipe file, that
> > is the twist.