Bash example

Nick-Stielaus-MacBook-Pro:chef-repo nstielau$ knife node log nstielau_vagrantup.com
Time                            Recipe                          Action                          Resource Type                   Resource                      
Tue May 10 10:25:20 -0700 2011  nginx::source                   create                          template                        proxy.conf                    
Tue May 10 10:25:20 -0700 2011  nginx::source                   enable                          service                         nginx                         
Tue May 10 09:50:42 -0700 2011  nginx::source                   create                          template                        /etc/init.d/nginx 

example_client.rb

log_level          :info
log_location       STDOUT
node_name          "nstielau_vagrantup.com"
ssl_verify_mode    :verify_none
.....
# Handlers
require "/var/chef/handlers/update_handler"
report_handlers << UpdateHandler.new()
....

knife_log_plugin.rb

require 'chef/knife'
require 'highline'

module Limelight
  class NodeLog < Chef::Knife

    deps do
      require 'chef/search/query'
      require 'chef/knife/search'
    end

    banner "knife node log NODE"

    def h
      @highline ||= HighLine.new
    end

    def run
      unless @node_name = name_args[0]
        ui.error "You need to specify a node"
        exit 1
      end

      searcher = Chef::Search::Query.new
      result = searcher.search(:node, "name:#{@node_name}")

      knife_search = Chef::Knife::Search.new
      node = result.first.first
      if node.nil?
        puts "Could not find a node named #{@node_name}"
        exit 1
      end

      $stdout.sync = true

      if node[:log]
        log_entries = [ h.color('Time', :bold),
                        h.color('Recipe', :bold),
                        h.color('Action', :bold),
                        h.color('Resource Type', :bold),
                        h.color('Resource', :bold) ]
        node[:log].each do |log_entry|
          log_entries << log_entry[:time].to_s
          log_entries << "#{log_entry[:cookbook_name]}::#{log_entry[:recipe_name]}"
          log_entries << log_entry[:action].to_s
          log_entries << log_entry[:resource_type].to_s
          log_entries << log_entry[:resource].to_s
        end
        puts h.list(log_entries, :columns_across, 5)
        puts
      end
    end
  end
end

update_handler.rb

require 'rubygems'
require 'chef/log'

class UpdateHandler < Chef::Handler
  def initialize(options={})
    @max_log_entries = (options[:max_log_entries] || 10).to_i
  end

  def report
    run_status.updated_resources.each do |resource|
      m = "recipe[#{resource.cookbook_name}::#{resource.recipe_name}] ran '#{resource.action}' on #{resource.resource_name} '#{resource.name}'"
      Chef::Log.debug(m)

      # Save entries to node
      node[:log] ||= []
      node[:log].insert(0, {
        :time => Time.now,
        :cookbook_name => resource.cookbook_name,
        :recipe_name => resource.recipe_name,
        :action => resource.action,
        :resource => resource.name,
        :resource_type => resource.resource_name
      })
      node[:log] = node[:log].first(@max_log_entries) if node[:log].length > @max_log_entries
    end
    node.save
  end
end