rsync する definitions

chef 的には cookbook_file とかでなんとかするべき

definitions/rsync.rb

class ::Chef
  class Definition
    # rsync files from a host to localhost
    #
    # HOW TO USE:
    #
    # 1)
    #
    #    rsync "#{name}" do
    #      from "#{hostname}:#{from_path}"
    #      to   "#{to_path}"
    #    end
    #    
    #    rsync "#{name}" do
    #      from "#{from_path}"
    #      to   "#{hostname}:#{to_path}"
    #    end
    #
    # 2) notifies must specify `execute` not `rsync`
    #
    #    cookbook_file "/tmp/foo" do
    #      source "tmp/foo"
    #      notifies :run, "execute[#{name}]"
    #    end
    #    
    #    rsync "#{name}" do
    #      from "#{from_path}"
    #      to   "#{hostname}:#{to_path}"
    #    end
    #
    # OPTIONS:
    #
    # * command 
    #   * rsync command with option. Default: /usr/bin/rsync -avzl --exclude=.git --delete -e ssh'
    # * from:
    #   * rsync src.
    # * to:
    #   * rsync dest.
    #
    # Other options are same with `execute` resource.
    # See https://docs.chef.io/resource_execute.html
    #
    # NOTICE:
    #
    # Chef orginally does not support to deploy files from remote hosts via rsync. 
    # That said, rsync way should be removed sooner or later, and using only built-in resouces
    # such as `remote_file`, `cookbook_file`, `template`, `remote_directory`is better. 
    module Rsync
      # default command
      def default_command
        '/usr/bin/rsync -avzl --exclude=.git --delete -e ssh'
      end
      module_function :default_command

      # build rsync command
      #
      # @param [String] command Default is self.default_command
      # @param [String] from
      # @param [String] to
      def build_command(command: nil, from: , to: )
        command ||= self.default_command
        "#{command} #{from} #{to}"
      end
      module_function :build_command
    end
  end
end

opts = {
  :command => ::Chef::Definition::Rsync.default_command,
  :from    => nil,
  :to      => nil,
}

define :rsync, opts do
  raise ArgumentError, "`to` is missing for rsync" unless params[:to]
  name = params[:name]
  from = params[:from] || params[:name] # hostname:/path/to/file
  to   = params[:to]
  from = from.call if from.is_a?(Chef::DelayedEvaluator)
  to   = to.call   if to.is_a?(Chef::DelayedEvaluator)
  rsync = ::Chef::Definition::Rsync.build_command(
    command: params[:command],
    from: from,
    to: to,
  )
  execute_params = params.dup.tap do |params|
    params.delete(:name)
    params.delete(:command)
    params.delete(:from)
    params.delete(:to)
  end
  execute_params[:command] ||= rsync
  # ToDo: find better way to achieve idempotence
  execute_params[:only_if] ||= "test $(#{rsync} -n 2>&1 | wc -l) -gt 4" # assume -v is used
  execute name do
    execute_params.each {|key, val| send(key, *val) }
  end
end