[chef] Re: Consuming a resource/provider from within another provider

[Andrea Campi < >]

On Thu, Apr 12, 2012 at 1:49 AM, James Dawson 
<
 >
 wrote:
> Hi,
>
> I'm trying to extend the 'Feature' resource in the Windows cookbook to also
> support using the Powershell module that is available in Windows 2008 R2.
>
> I was intending on using the Powershell resource/provider to actually
> execute the necessary commands, but am struggling to get this working - I've
> tried various combinations without much success but am new to Ruby so feel
> like I'm stumbling in the dark really.
>
> Here is how I'm trying to use it in my implementation of the 'installed?'
> method:
>
> def installed?
>   poshOutFile = Tempfile.new('feature_smm')
>   @installed ||= begin
>     Chef::Resource::Powershell.new("query feature") do
>       code <<-EOH
>         import-module ServerManager
>         $feature = Get-WindowsFeature 
> "
 "
>         Set-Content -Path "#{poshOutFile.path}"  -Value $feature.Installed
>       EOH
>     end
>
>     !(poshOutFile.nil?) && ((poshOutFile.read).casecmp 'true')
>   end
> end
>
> This particular attempt doesn't throw any errors but nothing actually
> happens, presumably because I'm only only instantiating the resource and not
> actually executing it. Other attempts typically resulted in 'method_missing'

Correct. You need:

resource.run_action(:create)

Note that this is in principle, I haven't taken the time do understand
the details—but you seem to be on right way to figure it out anyway ;)

> As a side question, I didn't see any way to pass information back from the
> invoked Powershell command (standard out doesn't seem to be accessible in
> the same way as with the 'shell_out' provider - or have I missed something
> here too?) so have resorted to using a file to store the result - is this
> the best approach?

You could probably take the guts out of that LWRP, create a helper in
libraries, and use that instead of the resource.
That's the approach I use when I need a return value; YMMV.

Andrea