validate_cmd in Puppet: supporting older versions - puppet

Question

I have the following Puppet code:
file { "/etc/sudoers.d/${name}":
content => template('sudo/sudoers.erb'),
owner => 'root',
group => 'root'
mode => '0440',
validate_cmd => '/usr/sbin/visudo -c -f %',
}
However, validate_cmd was only added in Puppet > 3.5, and I have to support some systems running 3.2 and older.
Is there some clever way of monkey-patching this into older versions of Puppet, or should I just resign to using the puppetlabs-stdlib validate_cmd statement?
Which does a similar thing, but won't revert the file if it does not validate correctly (the main benefit of the validate_cmd parameter on a fle).
EDIT: Using Felix's overwrite syntax, I ended up with the following code:
file { "/etc/sudoers.d/${name}":
content => template('sudo/sudoers.erb'),
owner => 'root',
group => 'root',
mode => '0440',
}
if versioncmp($::puppetversion, '3.5') >= 0 {
File["/etc/sudoers.d/${name}"] { validate_cmd => '/usr/sbin/visudo -c -f %' }
}
else {
validate_cmd(template('sudo/sudoers.erb'), '/usr/sbin/visudo -c -f', 'Visudo failed to validate sudoers content')
}
It's a bit fiddly to test in puppet-rspec, I ended up going with this:
if (Puppet.version >= '3.5.0')
context "validating content with puppet #{Puppet.version}" do
let(:params) { { :users => ['joe'] } }
let(:facts) {{ :puppetversion => Puppet.version }}
it { should contain_file('/etc/sudoers.d/worlddomination').with_validate_cmd('/usr/sbin/visudo -c -f %') }
end
else
context "validating content with puppet #{Puppet.version}" do
let(:params) { { :users => ['joe'] } }
let(:facts) {{ :puppetversion => Puppet.version }}
it { should contain_file('/etc/sudoers.d/worlddomination').with_validate_cmd(nil) }
end
end

Answer 1

Your manifest can adjust its behavior to the agent version.
file { "/etc/sudoers.d/${name}":
content => template('sudo/sudoers.erb'),
owner => 'root',
group => 'root'
mode => '0440',
}
if versioncmp($puppetversion, '3.5') >= 0 {
File["/etc/sudoers.d/${name}"] { validate_cmd => '/usr/sbin/visudo -c -f %' }
}
else {
# your workaround here
}
This will work courtesy of the puppetversion fact, of course.
The override syntax File[<name>] { ... } can be used like this because the actual resource declaration specifies no value for the validate_cmd attribute.