Could not find class, and yet it is there

Solution 1:

So... this is a bit embarrassing, but...

Environments.

Right there in my /etc/puppet.conf file is this:

[master]
  manifest=$confdir/manifests/site.pp
  modulepath=$confdir/environments/$environment/modules:$confdir/modules

After throwing strace at it to figure out where it was hunting for files, I noticed something. It was looking for custommod under /etc/puppet/environments/production/modules, and since there was a directory there (empty), it did not then go check /etc/puppet/modules. Apparently when importing a module it checks for directory-presence, rather than file-presence (init.pp).

Remove that empty directory, things start working.

Run the puppet agent using a different environment, things start working.

Moral of the story:

Puppet Environment paths do not act like bash $PATH.

Solution 2:

I ran into this same problem, but had a different fix

If you generate a puppet module like so:

puppet module generate foo-example_module

It will create a module named example_module with the foo name space. All the manifests will be inside a directory called foo-example_module

The name of the class defined in the init.pp needs to be the same as the folder name.

Simple fix:

mv foo-example_module example_module

If you run puppet-lint, it will warn with the following message:

ERROR: example_module not in autoload module layout on line 42

If using a Puppetfile with r10k or librarian-puppet, you also may need to remove the name space so that the files are placed without the 'foo' prefix in your modules directory.

before:

mod 'foo-example_module',
    :git => [email protected]:foo/example_module'

after:

mod 'example_module',
    :git => [email protected]:foo/example_module'

Solution 3:

Another problem that might happen is when your module have an invalid metadata.json file.

Make sure the metadata.json file have all the required fields (see https://docs.puppet.com/puppet/latest/reference/modules_metadata.html#allowed-keys-in-metadatajson )