Ohai plugin_path not being loaded on Windows 10

Question

Following Ron Cowie's guide in his book Customising Chef (O'Reilly) to creating simple Ohai plugin, it appears as though the Ohai plugins_path is not being loaded on my Windows 10 laptop.

Steps are as follows:

1. Create Example1.rb plugin file. I have done so in C:\dev\opscode\ohai\plugins\example1.rb

Ohai.plugin(:Example1) do 1
  provides "awesome_level" 2

  collect_data do 3
    awesome_level 100 4
  end
end

2. Run irb and type following:

PS C:\WINDOWS\system32> irb
irb(main):001:0> require 'ohai'
=> true
irb(main):002:0> Ohai::Config[:plugin_path] = 'C:/Dev/opscode/ohai/plugins'
=> "C:/Dev/opscode/ohai/plugins"
irb(main):003:0> o = Ohai::System.new
=> #<Ohai::System:0x0000000003c339a0 @cli=nil, @plugin_path="", @config={},...

It looks to me as though the @plugin_path is empty and so after running o.all_plugins and then o.attributes_print("awesome_level")

> Results in error: irb(main):019:0> puts
> o.attributes_print("awesome_level") Traceback (most recent call last):
>         3: from C:/opscode/chef-workstation/embedded/bin/irb.cmd:19:in `<main>'
>         2: from (irb):19
>         1: from C:/opscode/chef-workstation/embedded/lib/ruby/gems/2.5.0/gems/ohai-14.8.10/lib/ohai/system.rb:178:in
> `attributes_print' ArgumentError (I cannot find an attribute named
> awesome_level!)

Is it syntax for setting the plugins_path on Windows. I tried double-quotes. Backslashes.

Answer 1

My Chef install is not standard and the default C:\chef\ohai\plugins folder did not exist. If i used cmd line to add a directory to plugin path it worked:

ohai -d 'C:\dev\opscode\ohai\plugins'

This displayed all attributes from all plugins with right at the end my custom plugin

}, "awesome_level": 100

Answer 2

feels to me like you suffer from versioning issue -- to resolve any path and version issues, use bundler and lock your rubygems versions in a Gemfile.

here is an example:

$ bundle init
Writing new Gemfile to /private/var/folders/_2/rg7rz1h56sb2ln5f75gjr7558b1wz3/T/tmp.PPIvZRXi/Gemfile
$ echo "gem 'ohai'" >> Gemfile
$ bundle install --path vendor/gems --jobs 4
...

you mentioned that you are using chef. if you use ohai within chef-client run, then the plugin must be installed on the node that is managed by chef and before ohai is being load up in your recipe.