Creating new Knife plugins

Sometimes, you will be dealing with unique situations and need to create your own knife plugin. In this section, we will review how that is accomplished.

The basic plugin file format

A custom knife plugin begins by creating a new plugin ruby file. The plugin file has to have a specific format. That format, in its simplest form, looks like this:

require 'chef/knife'

module ModuleName
  class SubclassName < Chef::Knife

  deps do
    require 'chef/dependency'
  end

  banner 'knife subcommand argument VALUE (options)'

  option :name_of_option,
    :short => "-l VALUE",
    :long => "--long-option-name VALUE",
    :description => "The description for the option.",
    :proc => Proc.new { code_to_run }
    :boolean => true | false
    :default => default_value

  def run
  end
end

The essential sections of this file are:

• The required chef/knife directive provides the calls all knife plugins inherit from

• ModuleName is the name space for our plugin

• ...