Chef-Client Supermarket cookbook

• Using this cookbook from supermarket
  • Convergence can be changed
  • Scheduled jobs can be created
  • Chef-Client log locations can be changed.

Changing default convergance of a node to 2 hours.

• search for chef-client cookbook in Chef Supermarket. Refer Here
• Create a cookbook called as changecovnergence.
• Add depends 'chef-client', '~> 11.4.0' to metadata.rb
• Execute berks install
• create a attribute file called as default using chef generate attribute . default
• In the attributes/default.rb add the following line

default['chef_client']['interval'] = 7200

• In recipes/default.rb add the following line

include_recipe 'chef-client::default'

• Now upload this cookbook to chef server using berks upload and add this recipe to run_list of any node will change convergence from 30 minutes to 2 hours.

Scenario:

• The Servers look as shown below
• How do you design this deployment using chef
• Create 3 cookbooks
  • Mysql
  • tomcat
  • IIS Server
• use kitchen to verify cookbooks are working
• upload the cookbooks to chef server
• Ensure all the 8 servers are bootstrapped.
• Change the run_list of each server and add the necessary recipe or recipe list

Pain points

• Bootstrapping multiple servers
• Changing run list of every server

Change in scenario.

• Lets assume you are asked to install git on every node.
• For this we need to change the run list of every node.

Lets try to minimize efforts in Changing run_lists

• Chef has a concept called as role.

• Role is nothing but list of recipes.

• We create 3 roles

  • mysql-role => mysql::default
  • tomcat-role => tomcat::default
  • iis-role => iis::default

• In all the server where i need mysql to be installed in run_list i will add mysql-role

• In all the server where i need tomcat to be installed in run_list i will add tomcat-role

• In all the server where i need iis to be installed in run_list i will add iis-role

• If i need to add git to every node, there is no need to change run_list just edit the roles.

  • mysql-role => mysql::default, git::default
  • tomcat-role => tomcat::default, git::default
  • iis-role => iis::default, git::default

• Its always a best practice to have roles like

  • db-role
  • app-role
  • web-role