Dependency checks

[andytinycat]

This is an initial attempt at installing required package "depends" and "build_depends" with Puppet. Using Puppet's provider to do this means the hard work is done for us by the Puppet folks - no OS/platform detection required, which keeps things nice and simple.
Notes:

• It can't handle the version comparison forms (<<, >>, <=, >=) because Puppet can't handle them; we skip them and print a warning message.
• Handling an "or" string (packages separated with a pipe) isn't possible because we can't assume what the user wants, so we skip them and print a warning message.

[bernd]

This is nice! I was actually thinking about doing the same some days ago and started playing with puppet. (see https://gist.github.com/bernd/5028220) But your code looks simpler.

I was thinking about a separate command line action to install the dependencies because installing packages needs to be done as root and I usually build with an unprivileged user. fpm-cook can just run puppet if it's running as user root. If it's running as an unprivileged user it could show something like "Please run sudo fpm-cook install-deps to install ..."

What do you think?

[andytinycat]

Yeah, that's a good point. I normally build as root in a Vagrant VM (heresy, I know) so the thought didn't cross my mind.

Should be a trivial change; I'll hack on it tonight and ping you when it's done.

[andytinycat]

Better late than never.

This adds an extra command, "install-deps", that will attempt to install the dependencies with Puppet if run as root; if not, it complains.

In a build, if you're running as root, it'll try to install the dependencies; if not, it'll die and ask you to run install-deps with sudo.

How's this look to you?

[bernd]

Great, thank you! 👍