Question

Can someone explain to me why would this work :

node 'puppetagent'{
    $my_role="proxmoxnode"
    include role_proxmoxnode
}

class role_proxmoxnode {
    include sshdconf
}

And this won’t :

node 'puppetagent'{
    include role_proxmoxnode
}

class role_proxmoxnode {
    $my_role="proxmoxnode"
    include sshdconf
}

By “Work” I mean that the sshd_config.erb file set by sshdconf module will find the $my_role=”proxmoxnode” as expected. By “won’t work”, I mean the template complaining with “Could not find value for ‘my_role'”
I use puppet 3.0.

I followed the doc in http://projects.puppetlabs.com/projects/1/wiki/Infrastructure_Design_Guidelines about roles.

Thanks

Answer 1

In Puppet 3.0. unqualified variables are looked up in 4 places:

1. Local scope
2. Inherited from a base class
3. Node-level
4. Top scope

Local scope, by the way, would apply to variables defined in the class, not in classes which simply include it.

So, in your first example, we go looking:

1. Is it local? No.
2. Is it in a base class? No.
3. Is it in the node? yes. We stop.

In the second example…

1. Is it local? No.
2. Is it in a base class? No.
3. Is it in the node? No.
4. Is it in top scope? No. Fail.

Clear?