On Illumos LX, make Facter::Resolvers::Containers return nil, so Fact…

…er::Util::Facts::Posix::VirtualDetector#check_illumos_lx is executed

lib/facter/resolvers/containers.rb

@@ -49,6 +49,8 @@ def read_environ(fact_name)
             vm = 'podman'
           when 'crio'
             vm = 'crio'
+          when 'zone'
+            return nil
           when 'systemd-nspawn'
             vm = 'systemd_nspawn'
             info = { 'id' => Facter::Util::FileHelper.safe_read('/etc/machine-id', nil).strip }

spec/facter/resolvers/containers_spec.rb

@@ -78,6 +78,16 @@
     end
   end
 
+  context 'when hypervisor is illumos' do
+    let(:cgroup_output) { nil }
+    let(:environ_output) { ['container=zone'] }
+
+    it 'return nil' do
+      expect(containers_resolver.resolve(:vm)).to eq(nil)
+      expect(containers_resolver.resolve(:hypervisor)).to eq(nil)
+    end
+  end
+
   context 'when hypervisor is neighter lxc nor docker' do
     let(:cgroup_output) { load_fixture('cgroup_file').read }
     let(:environ_output) { ['PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin'] }