vagrant provision keeps reinstalling CPAN packages

[apennebaker]

Perl::Critic installs successfully on a fresh box with vagrant up. Then, every vagrant provision after that installs Perl::Critic again and again.

Source:

https://github.com/mcandre/mcandre-ubuntu

[alvagante]

The check for the presence of a module is done with perldoc -l :
$cpan_command_check = $ensure ? {
present => "perldoc -l ${name}",
absent => "perldoc -l ${name} || true",
}
so that specic module might not provide proper docs.
If you have better ways to verify if a perl module is installed let me know.

[apennebaker]

Good point, I'm not sure what to do in that case.

App::Ack mainly installs a binary, ack. But I'm not sure we could generalize this.

[alvagante]

What can easily be done is to add a parameter to the define that allows customization of the command to use to check for a module existence.
The default can keep on using perldoc, but in edge cases the user may provide a custom command, whatever it might be

[apennebaker]

Yeah! onlyif => "/usr/bin/test ! -f <file>" works well for Execs. Could Perl modules get this attribute as well?

[andrewblack]

Ubuntu doesn't (in my experience) install perldoc by default

$ perldoc -l perldoc
You need to install the perl-doc package to use this program.

[alvagante]

True, the perl class manages its installation (on Ubuntu).
I'm not a perl guru, and this is what I found online as a way to check, more or less reliably, for the precence of a module, if there are better methods please let me know.
In any case it makes sense to add an option to let users specify custom check commands, for cope with edge cases. I can do it when I find time (not likely in the near future), relevant PRs are welcomed.

[apennebaker]

Should Class['Perl'] require Package['perl-doc'] before attempting to install Perl modules?