[Puppet Users] Re: Adding a parameter to a custom Puppet type/provider

Hi Stefan,

On Wed, Dec 7, 2011 at 4:01 AM, Stefan Schulte
wrote:
Recently Nick L and I "discovered" that parameter validation does not
occur on the master (in 2.7.x) yet many people believe this to be
true. Specifically the munge and validate methods for parameters and
properties are not called on the puppet master. However, the type &
provider code is loaded, so for example, requiring a windows gem at
the top level would prevent the master (not running windows) from
being able to compile catalogs.

Did puppet actually used to invoke the validate method on the master,
e.g. before 2.6? Or is that just how people thought/think it should
work?

Josh

In 0.24.8 there were Puppet parameters "typecheck" and "paramcheck" defined
in defaults.rb, both initialized to true, and documented to control
"Whether to validate types during parsing" and "Whether to validate
parameters during parsing", respectively. These do not appear to actually
have been used in that version, however. Without digging through the code,
I'm not certain whether that means parse-time type and parameter checking
were always on or always off.

To the extent that validation is a function of the type, as opposed to the
selected provider, I would expect it to be performed by the master. I can
see some reasons why it might make sense for the agent to perform such
type-level validations again, but not to excuse the master from doing them.

I find it surprising that the master loads providers. On the other hand,
it should be *possible* for Puppet (any face) to load any installed
provider, including those that are not applicable to the host on which it
is running. I take this as part of Puppet's contract with providers, thus
the responsibility of the provider author. On the flip side, it is (should
be) Puppet's responsibility to check provider applicability after loading,
and to avoid using inapplicable providers for any purpose.


John