Another issue that can often hit you as your Puppet code base ages is unused code in your codebase. But, there's a tool out there in the wild we can use to keep on top of this issue.

puppet-ghostbuster essentially compares what is actually being used (stored in PuppetDB) to what you think you are using (in your code base directory). This give you the opportunity to slash and burn anything that's really unused. This is great from the point of view of software maintainability. A smaller code base is simply cheaper to maintain!

Let's quickly run through using this Ruby gem.

Make the following settings in your environment variables:

• HIERA_YAML_PATH: The location of the hiera.yaml file. It defaults to /etc/puppetlabs/code/hiera.yaml.
• PUPPETDB_URL: The URL or the PuppetDB. It defaults to http://puppetdb:8080.
• PUPPETDB_CACERT_FILE: Your site's CA certificate.
• PUPPETDB_CERT_FILE: A SSL certificate signed by your site's Puppet CA.
• PUPPETDB_KEY_FILE: The private key for that certificate.

Run the command as follows:

$ find . -type f -exec puppet-lint --only-checks ghostbuster_classes,ghostbuster_defines,ghostbuster_facts,ghostbuster_files,ghostbuster_functions,ghostbuster_hiera_files,ghostbuster_templates,ghostbuster_types {} +

You can add to and remove from the comma-delimited items to check for unused classes, defined types, facts, files, functions, Hiera files, templates, and types.