Add os.release facts on FreeBSD

[smortex]

This PR provide support for Facter 3.x os.release facts on FreeBSD to Facter 4:

Before:

romain@zappy ~/Projects/facter-ng % bundle exec bin/facter os        
cat: /etc/release: No such file or directory
[2020-04-29 18:51:23.841325 ] ERROR Facter::Resolvers::SolarisRelease - Could not build release fact because of missing or empty file /etc/release 
cat: /etc/release: No such file or directory
[2020-04-29 18:51:23.842256 ] ERROR Facter::Resolvers::SolarisRelease - Could not build release fact because of missing or empty file /etc/release 
cat: /etc/release: No such file or directory
[2020-04-29 18:51:23.843051 ] ERROR Facter::Resolvers::SolarisRelease - Could not build release fact because of missing or empty file /etc/release 
{
  architecture => "amd64",
  family => "FreeBSD",
  hardware => "amd64",
  name => "FreeBSD",
  release => {
    full => null,
    major => null,
    minor => null
  }
}

After:

romain@zappy ~/Projects/facter-ng % bundle exec bin/facter os      
{
  architecture => "amd64",
  family => "FreeBSD",
  hardware => "amd64",
  name => "FreeBSD",
  release => {
    branch => "RELEASE-p4",
    full => "12.1-RELEASE-p4",
    major => "12",
    minor => "1",
    patchlevel => "4"
  }
}

Compare to:

romain@zappy ~/Projects/facter-ng % facter os
{
  architecture => "amd64",
  family => "FreeBSD",
  hardware => "amd64",
  name => "FreeBSD",
  release => {
    branch => "RELEASE-p4",
    full => "12.1-RELEASE-p4",
    major => "12",
    minor => "1",
    patchlevel => "4"
  }
}

[puppetlabs-jenkins]

Can one of the admins verify this patch?

[smortex]

FreeBSD is definitively a descendant of BSD, yet BSD is not a decedent of Solaris (amusingly, early version of Sun OS (which became Solaris at some point) was based on BSD).

For now, this is convenient because Solaris facts and resolvers provide ZFS related facts which are working on FreeBSD, however, ZFS on Linux is a thing and some refactoring will be necessary at some point. Don't know how / where to log this so that it can be tracked…

[smortex]

And maybe it is as simple as renaming the Solaris ZFS resolver to make it obvious it is not Solaris specific and use similar facts for FreeBSD, Solaris and maybe Linux to gather these facts… So basically the same code facts multiple times, but maybe it's not a problem?

[BogdanIrimie]

@smortex I talked with @oanatmaria and maybe we can have something like

...
  {
    "Unix": [
      "Solaris",
      {
        "Bsd": [
          "Freebsd"
        ]
      }

    ]
  },
...

Both Solaris and Bsd will inherit from Unix. This is based on the diagram from https://upload.wikimedia.org/wikipedia/commons/7/77/Unix_history-simple.svg

[oanatmaria]

.strip will raise NoMethodError if output is empty string or if freebsd_version_results[0/1/2] is nil

[smortex]

freebsd-version -kru is expected to return exactly 3 lines (each flag produce a line), so I do not thing this is a problem for us here. Yet, some FreeBSD forks might be detected as "FreeBSD" while not providing freebsd-update, so it's worth being sure that the command succeeded.

[igalic]

HardenedBSD doesn't.

[smortex]

@igalic did you have the opportunity to try it on HardenedBSD? I need to allocate some time to dig in this project…

[igalic]

unfortunately, my current priority
canonical/cloud-init#363 is a few yak stacks away from testing HardenedBSD

[BogdanIrimie]

Great job with this PR @smortex and @oanatmaria !