Puppet 2.7 Cookbook

Drawing dependency graphs

Dependencies can get complicated quickly, and it's easy to end up with a circular dependency (where A depends on B which depends on A) which will cause Puppet to complain and stop work. Fortunately, Puppet's --graph option makes it easy to generate a diagram of your resources and the dependencies between them, which can be a big help in fixing such problems.

Getting ready…

Install the graphviz package to view the diagram files as shown in the following code snippet:

# apt-get install graphviz

How to do it…

1. Create the file /etc/puppet/modules/admin/manifests/ntp.pp with the following code containing a circular dependency:

   class admin::ntp {
       package { "ntp":
         ensure => installed,
         require => File["/etc/ntp.conf"], } service { "ntp": ...