[chef-dev] Re: Re: Ohai Ruby plugin: system ruby vs. running ruby?

[Jesse Nelson < >]

I see the need to differentiate the chef ruby (using rbconf) to figure
out what chef is running under. assuming you may need this for
developing some in-recipe things. I.e. i want to detect ruby 1.8 or
1.9 in my recipe. I know we can do that other ways in the recipe but
node['ruby"]["chef"]["version"]  makes sense to me.

I think pulling all other rubies is also good. For the times when i
want to unsure some other script code or framework will work.
node["ruby"]["system"]["jruby"]

I also see that you would want to detect the available rubies under
rvm.  node["ruby"]["rvm"]  for similar reasons.




On Wed, Aug 31, 2011 at 1:03 PM, Daniel DeLeo 
<
 >
 wrote:
> On Wednesday, August 31, 2011 at 12:59 PM, Brad Knowles wrote:
>> On Aug 31, 2011, at 2:52 PM, Daniel DeLeo wrote:
>>
>> > So, if your ohai attributes for languages/ruby are empty, what breaks?
>>
>> In my case, everything related to Chef. The system-provided version of 
>> ruby & rubygems is old enough that it will not work with anything related 
>> to Chef, and yet there are other parts of the system that are dependent on 
>> that older version being installed and being installed in the 
>> system-standard place. And they probably also do stupid things like 
>> assuming that the path is always set up correctly so if they just shell 
>> out to "ruby" it will pick up the right system-provided version.
>>
>>
>> So, I can't upgrade the system-provided version of ruby & ruby-gems, but I 
>> have to have the newer version of ruby & ruby-gems in order to get Chef & 
>> ohai to work.
>>
>> Both code bases want to assume that there is one and only one installation 
>> of ruby on the system, and it is necessarily the version that they need.
>>
>> That's a majorly, heinously, bad assumption.
>>
>>
>> You can't go back and fix all the legacy code that wants to make that 
>> one-and-only-one assumption, but you can at least ensure that all the new 
>> code will always be able to find the right version that it actually needs, 
>> without breaking or otherwise causing any disturbance for any of the older 
>> code.
>>
>> So, if you're going to program in Ruby, and you're going to build a system 
>> that requires newer version of the code than what we can get with a 
>> system-standard install, then the requirement falls onto you to make sure 
>> that you make things work properly. Don't break my existing production 
>> systems with your new code, and don't make me jump through hoops to get 
>> two incompatible versions installed.
>>
>> --
>> Brad Knowles 
>> <
 
>>  
>> (mailto:
 )>
> The change that I'm talking about is only related to how ohai collects data 
> about what ruby you have installed on the system. In Chef you can access 
> this data as node[:languages][:ruby]. Are you currently depending on this 
> data to return information about the system ruby?
>
> --
> Dan DeLeo
>
>