Eval and Converge a Single Chef Recipe

gistfile1.rb

#!/usr/bin/env ruby

recipe_path = ARGV[0]

if recipe_path.nil?
  STDERR.puts "usage: chef-apply RECIPE_FILE"
  exit 1
end

recipe_path = File.expand_path(recipe_path)

if !File.exist?(recipe_path)
  STDERR.puts "No file #{recipe_path}"
  exit 1
end

require 'rubygems'
require 'chef/client'
require 'chef/providers'
require 'chef/resources'

Chef::Log.level = :info

class Chef::Client
  attr_reader :events
end

# expedient.
Chef::Config[:solo] = true
client = Chef::Client.new
client.run_ohai
client.build_node

run_context = if client.events.nil?
  Chef::RunContext.new(client.node, {})
else
  Chef::RunContext.new(client.node, {}, client.events)
end

recipe = Chef::Recipe.new("(chef-apply cookbook)", "(chef-apply recipe)", run_context)
recipe.from_file(recipe_path)

runner = Chef::Runner.new(run_context)
runner.converge

In Chef 11.18.12 I also needed to call client.load_node before client.build_node. I think that will be the case for newer chefs too, according to what chef-shell does to create a solo session, e.g. https://github.com/chef/chef/blob/master/lib/chef/shell/shell_session.rb#L183