Chef: include_recipe only_if or not_if

06-10-2013 | Remy van Elst


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Chef supports including other recipes in cookbooks, for example, I can include the MySQL recipe from a PHP recipe. However, this is not a normal resource but a normal method. Therefore it ignores anything passed to it, including onlyif or notif. This tutorial shows you how to include or not include a recipe based on a variable, comparable with notif or onlyif.

Lets say you have a default recipe for all your nodes. It is a simple cookbook which includes other recipes via include_recipe. It sets standard configuration like users, ssh settings, mail settings and other stuff you want a server to have.

But what if you want to deploy a mailserver, which has other config than is included in your default recipe, but do want all the other stuff from the recipe? Probably you would change your recipe to something like:

include_recipe "postfix::server" do
  only_if node["defaults"]["postfix_server"] = true
end

This won't work. As said above, include_recipe is not a normal resource (like template or user) but a method. Therefore it ignores anything passed to it, including onlyif or notif.

The solution is quite simple, it fall back to using normal Ruby.

Note, there probably are more elegant solutions for this, but I find this to work quite well.

Instead of the above, try adding this to your cookbook:

this_node_is_postfix_server = node["defaults"]["postfix_server"] unless node["defaults"]["postfix_server"].nil?
include_recipe "postfix::server" if this_node_is_postfix_server

As you can see, regular Ruby fixes this problem.


Tags: chef  deployment  devops  not_if  only_if  ruby  tutorials