Chef 简明教程

Chef - ChefSpec

Test Driven Development (TDD) 是一种在编写任何实际的食谱代码之前编写单元测试的方法。测试应该是真实的，并且应该验证食谱的作用。由于没有开发食谱，它实际上应该会失败。一旦食谱开发完成，测试就应该通过。

Test Driven Development (TDD) is a way to write unit test before writing any actual recipe code. The test should be real and should validate what a recipe does. It should actually fail as there was no recipe developed. Once the recipe is developed, the test should pass.

ChefSpec 是建立在流行的 RSpec 框架之上的，它提供针对 Chef 食谱进行测试的定制语法。

ChefSpec is built on the popular RSpec framework and offers a tailored syntax for testing Chef recipe.

Creating ChefSpec

Step 1 − 创建包含 chefSpec gem 的 gem 文件。

Step 1 − Create a gem file containing the chefSpec gem.

vipin@laptop:~/chef-repo $ subl Gemfile
source 'https://rubygems.org'
gem 'chefspec'

Step 2 − 安装 gem。

Step 2 − Install the gem.

vipin@laptop:~/chef-repo $ bundler install
Fetching gem metadata from https://rubygems.org/
...TRUNCATED OUTPUT...
Installing chefspec (1.3.1)
Using bundler (1.3.5)
Your bundle is complete!

Step 3 − 创建一个 spec 目录。

Step 3 − Create a spec directory.

vipin@laptop:~/chef-repo $ mkdir cookbooks/<Cookbook Name>/spec

Step 4 − 创建 Spec

Step 4 − Create a Spec

vipin@laptop:~/chef-repo $ subl
cookbooks/my_cookbook/spec/default_spec.rb
require 'chefspec'
describe 'my_cookbook::default' do
   let(:chef_run) {
      ChefSpec::ChefRunner.new(
         platform:'ubuntu', version:'12.04'
      ).converge(described_recipe)
   }

   it 'creates a greetings file, containing the platform
   name' do
      expect(chef_run).to
      create_file_with_content('/tmp/greeting.txt','Hello! ubuntu!')
   end
end

Step 5 − 验证 ChefSpec。

Step 5 − Validate ChefSpec.

vipin@laptop:~/chef-repo $ rspec cookbooks/<Cookbook Name>/spec/default_spec.rb
F
Failures:
1) <CookBook Name> ::default creates a greetings file, containing the platform name
Failure/Error: expect(chef_run.converge(described_recipe)).to
create_file_with_content('/tmp/greeting.txt','Hello! ubuntu!')
File content:
does not match expected:
Hello! ubuntu!
# ./cookbooks/my_cookbook/spec/default_spec.rb:11:in `block
(2 levels) in <top (required)>'
Finished in 0.11152 seconds
1 example, 1 failure

Failed examples:
rspec ./cookbooks/my_cookbook/spec/default_spec.rb:10 # my_
cookbook::default creates a greetings file, containing the
platform name

Step 6 − 编辑 Cookbooks 默认配方。

Step 6 − Edit Cookbooks default recipe.

vipin@laptop:~/chef-repo $ subl cookbooks/<Cookbook Name>/recipes/default.rb
template '/tmp/greeting.txt' do
   variables greeting: 'Hello!'
end

Step 7 − 创建模板文件。

Step 7 − Create a template file.

vipin@laptop:~/chef-repo $ subl cookbooks/< Cookbook Name>/recipes/default.rb
<%= @greeting %> <%= node['platform'] %>!

Step 8 − 再次运行 rspec。

Step 8 − Run the rspec again.

vipin@laptop:~/chef-repo $ rspec cookbooks/<Cookbook Name>/spec/default_spec.rb
.
Finished in 0.10142 seconds
1 example, 0 failures

How It Works

为了使其生效，我们需要首先为 RSpec 设置针对 Chef 使用的基础设施。然后我们需要使用 ChefSpec Ruby gem，并且 Cookbook 需要一个目录（名为 spec），所有测试都将保存其中。

In order to make it work, we need to first set up the base infrastructure for using RSpec with Chef. Then we need to ChefSpec Ruby gem and the cookbook needs a directory called spec where all the tests will be saved.