How to write Reusable Recipes?

Here are some good practices to write reusable recipes.

1. Be as Minimal as Possible

To maximize reusability, make your recipe as minimal as possible.
The functional scope should be clearly defined. And it should have the fewest dependencies.

2. Name it correctly

Try to follow this convention.


As an example, puppet-apache-mod-jk-latest indicates the recipe is based on Puppet and that it manages the last version of Apache with mod_jk.

3. Coherence

Use the same name for the Maven artifact ID, the module name and the Git repository (if you use Git).

4. Do not add a Descriptor

Unlike complete applications, recipes do not need an application descriptor.
This is always true, unless your recipe contains more than one graph files right under the graph directory.

5. Exported Variables must be used in Recipes

If a component exports a variable, then it should be used in its recipe.
Indeed, exported variables can be overridden by instances and sub-components. If it is overridden, then the recipe should use the value set by the user. Otherwise, inconsistency may occur.

As an example, if you have a component called Apache and that it exports a port variable, then the recipe should update the Apache configuration if a user chooses another port than the default one.