DevOps Classroom Series – 04/Dec/2019

Environment File

• In the chef-repo file create folder called as environments
• In the environments create two files called as qa.rb and uat.rb
• qa.rb contents are

name "qa"
description "This is the qa version"
cookbook_versions({
  'envroledemo'=>'= 1.1.0'
})

• uat.rb contents are

name "uat"
description "This is the uat version"
cookbook_versions({
  'envroledemo'=>'= 1.0.0'
})

• Upload environments to chef server using knife environment from file <filename>
• Apply environment to nodes

Attribute Precedence:

• Attributes can be defined in

  • recipe
  • Attributes files
  • role
  • environment

• Each Attribute has type.

  • default
  • force_default
  • normal
  • override
  • force_override

• Chef defines priority for each position in the combination of Place of Attribute definition and Attribute Type

• Refer

Chef Templates

• Templates are used for configuration files.
• Consider this scenario.
• Install apache server. Create a file called as index.html in /var/www/html/index.html with following content

Hello , 
Operating System is <os>
ip address is <ipadress>

• Generate cookbook

chef generate cookbook -b templatedemo

• Now generate a template

chef generate template . index.html

• A new folder called as templates with index.html.erb file gets created.
• In this file add the following content

Hi,
Operating System is <%= node['platform'] %>
Ip address is <%= node['ipaddress'] %>

• In the recipes\default.rb file add the template resource

template 'home/ubuntu/index.html' do
    source 'index.html.erb'
    action :create
end

• upload and test this cookbook in kitchen to find the dynamic values in the index.html on the node.