Add os.release facts on FreeBSD (#485)

* (maint) Add os.release facts on FreeBSD
* (maint) Improve freebsd-version failure management

This program is always supposed to be found and return the expected
output on FreeBSD but make sure it runs successfully, catpure stderr in
case it becomes used at some point, and do not raise exceptions if the
resolver fails.

* (maint) Improve failing fact resolution
If the resolver fails to gather the fact, return an empty resolved fact
instead of an empty array.

lib/facts/freebsd/os/release.rb

@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+module Facts
+  module Freebsd
+    module Os
+      class Release
+        FACT_NAME = 'os.release'
+        ALIASES = %w[operatingsystemmajrelease operatingsystemrelease].freeze
+
+        def call_the_resolver
+          installed_userland = Facter::Resolvers::Freebsd::FreebsdVersion.resolve(:installed_userland)
+
+          return Facter::ResolvedFact.new(FACT_NAME, nil) if !installed_userland || installed_userland.empty?
+
+          value = build_release_hash_from_version(installed_userland)
+
+          [Facter::ResolvedFact.new(FACT_NAME, value),
+           Facter::ResolvedFact.new(ALIASES.first, value[:major], :legacy),
+           Facter::ResolvedFact.new(ALIASES.last, installed_userland, :legacy)]
+        end
+
+        private
+
+        def build_release_hash_from_version(version_string)
+          version, branch_value = version_string.split('-', 2)
+          major_value, minor_value = version.split('.')
+          patchlevel_value = branch_value.split('-p')[1]
+
+          value = {
+            full: version_string,
+            major: major_value,
+            branch: branch_value
+          }
+
+          value[:minor] = minor_value if minor_value
+          value[:patchlevel] = patchlevel_value if patchlevel_value
+
+          value
+        end
+      end
+    end
+  end
+end

lib/framework/detector/os_detector.rb

@@ -24,6 +24,8 @@ def detect
                    :macosx
                  when /linux/
                    detect_distro
+                 when /freebsd/
+                   :freebsd
                  when /bsd/
                    :bsd
                  when /solaris/

lib/resolvers/freebsd/freebsd_version_resolver.rb

@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+module Facter
+  module Resolvers
+    module Freebsd
+      class FreebsdVersion < BaseResolver
+        @semaphore = Mutex.new
+        @fact_list ||= {}
+
+        class << self
+          private
+
+          def post_resolve(fact_name)
+            @fact_list.fetch(fact_name) { freebsd_version_system_call(fact_name) }
+          end
+
+          def freebsd_version_system_call(fact_name)
+            output, _stderr, status = Open3.capture3('/bin/freebsd-version -kru')
+            return nil unless status.success?
+
+            build_fact_list(output)
+
+            @fact_list[fact_name]
+          rescue Errno::ENOENT
+            nil
+          end
+
+          def build_fact_list(output)
+            freebsd_version_results = output.split("\n")
+
+            @fact_list[:installed_kernel]   = freebsd_version_results[0].strip
+            @fact_list[:running_kernel]     = freebsd_version_results[1].strip
+            @fact_list[:installed_userland] = freebsd_version_results[2].strip
+          end
+        end
+      end
+    end
+  end
+end

os_hierarchy.json

@@ -24,7 +24,11 @@
   },
   {
     "Solaris": [
-      "Bsd"
+      {
+        "Bsd": [
+          "Freebsd"
+        ]
+      }
     ]
   },
   "Macosx",

spec/facter/facts/freebsd/os/release_spec.rb

@@ -0,0 +1,71 @@
+# frozen_string_literal: true
+
+describe Facts::Freebsd::Os::Release do
+  describe '#call_the_resolver' do
+    subject(:fact) { Facts::Freebsd::Os::Release.new }
+
+    before do
+      allow(Facter::Resolvers::Freebsd::FreebsdVersion).to receive(:resolve).with(:installed_userland).and_return(value)
+    end
+
+    context 'when FreeBSD RELEASE' do
+      let(:value) { '12.1-RELEASE-p3' }
+
+      it 'calls Facter::Resolvers::Freebsd::FreebsdVersion' do
+        fact.call_the_resolver
+        expect(Facter::Resolvers::Freebsd::FreebsdVersion).to have_received(:resolve).with(:installed_userland)
+      end
+
+      it 'returns release fact' do
+        expect(fact.call_the_resolver).to be_an_instance_of(Array).and \
+          contain_exactly(an_object_having_attributes(name: 'os.release', value: { 'full' => value,
+                                                                                   'major' => '12',
+                                                                                   'minor' => '1',
+                                                                                   'branch' => 'RELEASE-p3',
+                                                                                   'patchlevel' => '3' }),
+                          an_object_having_attributes(name: 'operatingsystemmajrelease', value: '12',
+                                                      type: :legacy),
+                          an_object_having_attributes(name: 'operatingsystemrelease', value: value, type: :legacy))
+      end
+    end
+
+    context 'when FreeBSD STABLE' do
+      let(:value) { '12.1-STABLE' }
+
+      it 'calls Facter::Resolvers::Freebsd::FreebsdVersion' do
+        fact.call_the_resolver
+        expect(Facter::Resolvers::Freebsd::FreebsdVersion).to have_received(:resolve).with(:installed_userland)
+      end
+
+      it 'returns release fact' do
+        expect(fact.call_the_resolver).to be_an_instance_of(Array).and \
+          contain_exactly(an_object_having_attributes(name: 'os.release', value: { 'full' => value,
+                                                                                   'major' => '12',
+                                                                                   'minor' => '1',
+                                                                                   'branch' => 'STABLE' }),
+                          an_object_having_attributes(name: 'operatingsystemmajrelease', value: '12',
+                                                      type: :legacy),
+                          an_object_having_attributes(name: 'operatingsystemrelease', value: value, type: :legacy))
+      end
+    end
+
+    context 'when FreeBSD CURRENT' do
+      let(:value) { '13-CURRENT' }
+
+      it 'calls Facter::Resolvers::Freebsd::FreebsdVersion' do
+        fact.call_the_resolver
+        expect(Facter::Resolvers::Freebsd::FreebsdVersion).to have_received(:resolve).with(:installed_userland)
+      end
+
+      it 'returns release fact' do
+        expect(fact.call_the_resolver).to be_an_instance_of(Array).and \
+          contain_exactly(an_object_having_attributes(name: 'os.release', value: { 'full' => value,
+                                                                                   'major' => '13',
+                                                                                   'branch' => 'CURRENT' }),
+                          an_object_having_attributes(name: 'operatingsystemmajrelease', value: '13',
+                                                      type: :legacy),
+                          an_object_having_attributes(name: 'operatingsystemrelease', value: value, type: :legacy))
+      end
+    end
+  end
+end

spec/facter/resolvers/freebsd/freebsd_version_resolver_spec.rb

@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+describe Facter::Resolvers::Freebsd::FreebsdVersion do
+  before do
+    status = instance_double('Process::Status')
+    allow(status).to receive(:success?).and_return(true)
+    allow(Open3).to receive(:capture3)
+      .with('/bin/freebsd-version -kru')
+      .and_return(['13.0-CURRENT
+        12.1-RELEASE-p3
+        12.0-STABLE', nil, status])
+  end
+
+  it 'returns installed kernel' do
+    result = Facter::Resolvers::Freebsd::FreebsdVersion.resolve(:installed_kernel)
+
+    expect(result).to eq('13.0-CURRENT')
+  end
+
+  it 'returns running kernel' do
+    result = Facter::Resolvers::Freebsd::FreebsdVersion.resolve(:running_kernel)
+
+    expect(result).to eq('12.1-RELEASE-p3')
+  end
+
+  it 'returns installed userland' do
+    result = Facter::Resolvers::Freebsd::FreebsdVersion.resolve(:installed_userland)
+
+    expect(result).to eq('12.0-STABLE')
+  end
+end