Start writing modules for *nix

Write, test, and deploy a module class for an example module.

1. In the pe_getstarted_app directory, create the main class for your module by running pdk new class pe_getstarted_app

   When you create a class with the same name as your module, PDK creates the init.pp file. This file contains the main class of a module, and it's the only class with a file name that's different from the class name. PDK also creates testing directories and templates for the class.

2. Validate your class's code syntax and style by running pdk validate
3. Unit test your class by running pdk test unit
4. Open the init.pp file in your text editor and add the following Puppet code to it. Save the file and exit the editor.

   class pe_getstarted_app (
     $content = "<?php phpinfo() ?>\n",
   ) {
   
      class { 'apache':
        mpm_module => 'prefork',
      }
   
      include apache::mod::php
   
      apache::vhost { 'pe_getstarted_app':
        port     => '80',
        docroot  => '/var/www/pe_getstarted_app',
        priority => '10',
      }
   
      file { '/var/www/pe_getstarted_app/index.php':
        ensure  => file,
        content => $content,
        mode    => '0644',
      }
   
    }

   Additional details about the code in your new class:

   • The class apache is modified to include the mpm_module attribute. This attribute determines which multi-process module is configured and loaded for the Apache (HTTPD) process. In this case, the value is set to 'prefork'.

   • include apache::mod::php indicates that your new class relies on those classes to function correctly. PE understands that your node needs to be classified with these classes and completes that work automatically when you classify your node with the pe_getstarted_app class; in other words, you don’t need to worry about classifying your nodes with Apache and Apache PHP.

   • The priority attribute of '10' ensures that your app has a higher priority on port 80 than the default Apache vhost app.

   • The file /var/pe_getstarted_app/index.php contains whatever is specified in the content attribute. This is the content you see when you launch your app. PE uses the ensure attribute to create that file the first time the class is applied.

Validate and unit test a class in an example module.

1. In the pe_getstarted_app directory, create a .fixtures.yml file. This file installs module dependencies for unit testing.
2. Open the .fixtures.yml file and edit it to include the following code. Save the file and exit the editor.

   fixtures:
     forge_modules:
        apache: "puppetlabs/apache"
        stdlib: "puppetlabs/stdlib"
        concat: "puppetlabs/concat"

3. Change into the spec tests directory by running cd spec/classes.
4. Open the pe_getstarted_app_spec.rb in your text editor and add the following code. Save and exit the file.

   require 'spec_helper'
   
   describe 'pe_getstarted_app', type: :class do
     let(:facts) do
      {
        operatingsystemrelease: '14.04', 
        osfamily: 'Debian',
        operatingsystem: 'Ubuntu',
        lsbdistrelease: 'Trusty',
   
       }
     end
   
     describe 'standard content' do
       it { is_expected.to contain_class('apache').with('mpm_module' => 'prefork') }
     
       it {
         is_expected.to contain_apache__vhost('pe_getstarted_app').with(
           'port' => '80',
         )
       }
     
      it {
       is_expected.to contain_file('/var/www/pe_getstarted_app/index.php').with(
           'ensure'  => 'file',
           'content' => "<?php phpinfo() ?>\n",
           'mode' => '0644'
         )
       }
     end
   
     describe 'custom content' do
       let(:params) do
         { 'content' => "custom\n", }
       end
   
       it {
         is_expected.to contain_file('/var/www/pe_getstarted_app/index.php').with(
           'ensure'  => 'file',
           'content' => "custom\n",
           'mode' => '0644'
         )
       }
     end
   end
   

5. Run pdk validate to check the code style and syntax of your class. 
6. Run pdk test unit to run your unit test against your class.