null created by darelvc - https://repl.it/JqDH/12

JqDH-12.rb

require 'json'

a = { "system": {"cpu": {"softirq": {"pct": 0}, "idle": {"pct": 0.992}, "steal": {"pct": 0}, "cores": 1, "system": { "pct": 0.0003 }, "iowait": { "pct": 0.007 }, "irq": { "pct": 0 }, "user": { "pct": 0.0007 }, "nice": { "pct": 0 } }} }

parsed = a.to_json

json_parsed = JSON.parse(parsed)

global_key = json_parsed.keys()

json_parsed[global_key[0]].each do |key, value|
  
  second_key = key
  # puts second_key
  value.each do |k, v|
    if v.is_a?(Hash)
      v.each do |z, x|
        puts "#{global_key[0]}.#{second_key}.#{k}.#{z} #{x}"
      end
    else
      puts "#{global_key[0]}.#{second_key}.#{k} #{v}"
    end
  end
end