Ruby Hash Not Populating-CodePudding

I am working in Chef, trying to create/populate a ruby hash with networking device information, as populated by nmcli. I think the code is correct, as VS Code isn't complaining, and it seems to run just fine in chef-shell -z but I'm not able to query the Ruby Hash as I would expect, and I'm really starting to lose my mind.

Fresh eyes and any expert help here are appreciated, thank you!

interfaces = Hash.new
#DEVICE,TYPE
dev = Mixlib::ShellOut.new("nmcli -terse -field device,type device").run_command.stdout.split(/\n/)
dev.each do |output|
  if "#{output.split(":")[1]}" == 'ethernet'
    interfaces["ethernet" => "#{output.split(":")[0]}"]
  elsif "#{output.split(":")[1]}" == 'wifi'
    interfaces["wifi" => "#{output.split(":")[0]}"]
  else
    Chef::Log.debug("Interface #{output.split(":")} is not supported")
  end
end
chef (17.6.18)>  
 => ["wlp61s0:wifi", "enp0s31f6:ethernet", "lo:loopback"] 
node[interfaces] #nil
node[:interfaces] #nil
node['interfaces'] #nil
node["interfaces"] #nil

When I attempt to edit the code, as suggested by BroiSatse

This line interfaces["wifi" => "#{output.split(":")[0]}"] returns the value stored in the hash under the key {"wifi" => "#>{output.split(":")[0]}"}. It does not perform any assignment and most > likely returns nil.

What you need is:

interfaces["wifi"] ="#{output.split(":")[0]}"

So I tried that, but I still get a nil response from the Hash. Here is the Chef output/error:

chef (17.6.18)> interfaces = Hash.new
chef > #DEVICE,TYPE
chef (17.6.18)> dev = Mixlib::ShellOut.new("nmcli -terse -field device,type device").run_command.stdout.split(/\n/)
 => ["wlp61s0:wifi", "enp0s31f6:ethernet", "lo:loopback"] 
chef > dev.each do |output|
chef >   if "#{output.split(":")[1]}" == 'ethernet'
chef >     interfaces["ethernet"] = "#{output.split(":")[0]}"
chef >   elsif "#{output.split(":")[1]}" == 'wifi'
chef >     interfaces["wifi"] = "#{output.split(":")[0]}"
chef >   else
chef >     Chef::Log.debug("Interface #{output.split(":")} is not supported")
chef >   end
chef (17.6.18)> end
 => ["wlp61s0:wifi", "enp0s31f6:ethernet", "lo:loopback"] 
chef (17.6.18)> node[interfaces] #nil
 => nil 
chef (17.6.18)> node[:interfaces][:ethernet] #nil
(irb):95:in `<main>': undefined method `[]' for nil:NilClass (NoMethodError)
    from /opt/chef/embedded/lib/ruby/gems/3.0.0/gems/chef-17.6.18/lib/chef/shell.rb:93:in `block in start'
    from /opt/chef/embedded/lib/ruby/gems/3.0.0/gems/chef-17.6.18/lib/chef/shell.rb:92:in `catch'
    from /opt/chef/embedded/lib/ruby/gems/3.0.0/gems/chef-17.6.18/lib/chef/shell.rb:92:in `start'
    from /opt/chef/embedded/lib/ruby/gems/3.0.0/gems/chef-bin-17.6.18/bin/chef-shell:31:in `<top (required)>'
    from /usr/bin/chef-shell:158:in `load'
    from /usr/bin/chef-shell:158:in `<main>'
chef (17.6.18)> node['interfaces'] #nil
chef (17.6.18)> node["interfaces"] #nil
 => nil 
chef (17.6.18)>

UPDATE: Monday May 2, 2022 12:08 PST

When I do this command I can see that there is data in the Hash ... but all attempts to actually query the data fail ... I don't know what I'm doing wrong:

chef (17.6.18)> puts "#{interfaces}"
{"wifi"=>"wlp61s0", "ethernet"=>"enp0s31f6"}
 => nil 
chef (17.6.18)>

CodePudding user response：

Just call

interfaces["ethernet"]

interfaces["wifi"]

interfaces = {}

dev =
  Mixlib::ShellOut.new("nmcli -terse -field device,type device").
    run_command.
    stdout.
    lines(chomp: true)

dev.each do |output|
  device, type_device = output.split(":")

  case type_device
  when "ethernet", "wifi"
    interfaces[type_device] = device
  else
    Chef::Log.debug("Interface #{output} is not supported")
  end
end

Note: there will be just one key wifi and ethernet. So if you have more devices, just last value will be used

CodePudding user response：

The following line of code returns the value stored in the hsh under the key {"wifi" => "#{output.split(":")[0]}"}. It does not perform any assignment and most likely returns nil.

interfaces["wifi" => "#{output.split(":")[0]}"]

What you need is:

interfaces["wifi"] = "#{output.split(":")[0]}"