(FACT-852) Support for systemd and systemd_version

[Spredzy]

This commit adds support for systemd and systemd_version facts.

[daenney]

Should this additionally be confined to :systemd => true?

[Spredzy]

@daenney you're right. Fixed.

[puppetcla]

CLA signed by all contributors.

[joshcooper]

I think you just want to do:

setcode do
   ...
   init_process_name == 'systemd'
end

In other words, the value of the fact should be the last value of the setcode block. If you're on a systemd system, then the last value is true due to evaluating result = true, e.g.

irb(main):001:0> result = true
=> true

If you're not on systemd, then the value is actually coming from the if check:

irb(main):002:0> if 1 == 2
irb(main):003:1> end
=> nil

[daenney]

Actually, wouldn't we want this instead?

setcode do
  if Facter::Core::Execution.exec('ps -p 1 -o comm=').eql? 'systemd'
    true
  else
    false
  end
end

[joshcooper]

or just

setcode do
  Facter::Core::Execution.exec('ps -p 1 -o comm=') == 'systemd'
end

[daenney]

Oh good point!

[melissa]

Thanks for the contribution!

However, we likely aren't going to do any more releases from the master branch of facter. This looks like work that should be targeted at Facter 3, our native implementation in C++. @MikaelSmith do you have any input on this?

Backstory: https://groups.google.com/forum/#!msg/puppet-dev/tBqHZB9M308/QqdaldMsJlkJ

[MikaelSmith]

Yes, this will need an additional ticket to cover Facter 3.

[MikaelSmith]

We plan to make that more obvious soon by moving the Facter 3 codebase to facter#master.

[kylog]

Agreed. I'd target this at Facter 3. And yes, the codebase move will make this all more obvious. Coming soon!

For backstory: https://groups.google.com/forum/#!msg/puppet-dev/tBqHZB9M308/QqdaldMsJlkJ

[kylog]

One other thing: I'd add these two facts as a single new structured fact.

[daenney]

How would you name it then though? One is binary, one is data:

systemd { active => true, version => $version }

It feels awkward.

[kylog]

Hmm, well, naming is hard, but:

systemd { active => true, version => 212 }

actually makes sense to me. And then in code you could reference:

systemd[active]
systemd[version]

Although ... would it be worth generalizing it to service_managers or some such? That feels like an awkward name, but would allow sth like:

if service_manager[type] == 'systemd' ....

[daenney]

init_system?

[branan]

Per the existing discussion on this ticket and the concensus in the PR triage discussion meeting, I'm going to close this. New features should be targeted at cfacter as we get ready to release facter 3.

[melissa]

Just an update to this, we moved the CFacter code into the facter/master branch. So this work should be targeted there.