How to override puppet class arguments in child node?

Question

I'm attempting to accomplish something like the below:

node 'basenode' {
    class {
        'puppet' :
         disable => false,
    }
}
node 'child' inherits 'basenode' {
class {
        'puppet' :
         disable => true,
    }
}

This gives me:

err: Could not retrieve catalog from remote server: Error 400 on SERVER: Duplicate definition: Class[Puppet] is already defined

How can I override this setting for this single node, and still have a parameterised class?

Answer 1

Turns out this is a known issue: https://projects.puppetlabs.com/issues/5517

Answer 2

It's generally not good design to do node inheritance like this. Create abstract "roles" layer in a different file at /etc/puppet/manifests/roles.pp. And then pass parameters to those classes instead.

site.pp

import "roles.pp"
import "nodes.pp"

nodes.pp

node 'webserver1' {
    class{"role::webserver":}
}

node 'webserver2' {
    class{"role::webserver":
        do_stuff => false,
    }
}

node 'db' {
    class{"role::db":}
}

roles.pp

class role($do_stuff) {
    class{'foo': do_stuff => $do_stuff,}
}

class role::webserver($do_stuff=true) {
    class{'role':
        do_stuff => $do_stuff,
    }

    class{'apache':
        other_stuff => 'foo',
    }
}

class role::webserver($do_stuff=true) {
    class{'role': do_stuff => $do_stuff,}
    class{'apache': other_stuff => 'foo',}
}

class role::db($do_stuff=true) {
    class{'role': do_stuff => $do_stuff,}
    class{'postgres': other_stuff => 'foo',}
}