conditional within define in puppet - puppet

Question

Running Puppet 3.8
I have two defines:
define desktop::vinstall () {
package { $title:
ensure => installed,
allow_virtual => true,
configfiles => keep,
}
}
and
define desktop::vinstallwseeds () {
package { $title:
ensure => installed,
allow_virtual => true,
configfiles => keep,
require => File["/var/cache/debconf/pkg-${title}.seeds"],
responsefile => "/var/cache/debconf/pkg-${title}.seeds",
}
file { "/var/cache/debconf/pkg-${title}.seeds":
source => "puppet:///modules/desktop/pkg-${title}.seeds",
ensure => present,
}
}
Would like to turn these into one define statement with an optional boolean argument, something like:
define desktop::vinstallopt ( $queryresponse = 'false', ) {
package { $title:
ensure => installed,
allow_virtual => true,
configfiles => keep,
if $queryresponse == 'true' {
require => File["/var/cache/debconf/pkg-${title}.seeds"],
responsefile => "/var/cache/debconf/pkg-${title}.seeds",
}
}
file { "/var/cache/debconf/pkg-${title}.seeds":
source => "puppet:///modules/desktop/pkg-${title}.seeds",
ensure => present,
}
}
and then instantiate it with statements like this one in init.pp:
#desktop::vinstallopt { 'gdebi': queryresponse => 'false', }
But doing so gives an error:
Error: Could not retrieve catalog from remote server: Error 400 on SERVER: Puppet::Parser::AST::Resource failed with argument error ArgumentError: Invalid resource type desktop::vinstallopt at /etc/puppet/modules/desktop/manifests/init.pp:40 on node machine.prvt.net
where line 40 has the syntax above. I'm a newbie with puppet, so my apologies if this turns out the be a simple syntax question. I've tried to find a way to make this work from the PuppetLabs documentation and from other puppet users, so far without luck.

Answer 1

You are trying to embed an if block inside a resource declaration. Alas, this is not possible. The block must be global or in a regular block (e.g., class body, define body, lambda body).
In this case, you want to "amend" the package resource, so to speak. I like to use the following construct for this purpose:
package { $title:
ensure => installed,
allow_virtual => true,
configfiles => keep,
}
if $queryresponse {
Package[$title] {
require => File["/var/cache/debconf/pkg-${title}.seeds"],
responsefile => "/var/cache/debconf/pkg-${title}.seeds",
}
}
Please note that this override syntax is only allowed in this scope because the require and responsefile attributes don't have any value assigned originally.