(FACT-2689) Add docker fact

CHANGELOG.md

@@ -4,11 +4,11 @@
 
 ### Added
 - \(FACT-2218\) virtual fact for OSX [\#1945](https://github.com/puppetlabs/facter/pull/1945) ([IrimieBogdan](https://github.com/IrimieBogdan))
-- \(FACT-2232\) Add Aix networking facts [\#1937](https://github.com/puppetlabs/facter-ng/pull/1937) ([oanatmaria](https://github.com/oanatmaria))
+- \(FACT-2232\) Add Aix networking facts [\#1937](https://github.com/puppetlabs/facter/pull/1937) ([oanatmaria](https://github.com/oanatmaria))
 
 ### Fixed
-- \(FACT-2676\) fix os identifier for opensuse-leap [\#1944](https://github.com/puppetlabs/facter-ng/pull/1944) ([Filipovici-Andrei](https://github.com/Filipovici-Andrei))
-- FACT-2679 Get DHCP for all interfaces on OSX [\#1940](https://github.com/puppetlabs/facter-ng/pull/1940) ([Filipovici-Andrei](https://github.com/Filipovici-Andrei))
+- \(FACT-2676\) fix os identifier for opensuse-leap [\#1944](https://github.com/puppetlabs/facter/pull/1944) ([Filipovici-Andrei](https://github.com/Filipovici-Andrei))
+- FACT-2679 Get DHCP for all interfaces on OSX [\#1940](https://github.com/puppetlabs/facter/pull/1940) ([Filipovici-Andrei](https://github.com/Filipovici-Andrei))
 
 ## [4.0.28](https://github.com/puppetlabs/facter/tree/4.0.28) (2020-06-25)
 

lib/facts/linux/hypervisors/docker.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+module Facts
+  module Linux
+    module Hypervisors
+      class Docker
+        FACT_NAME = 'hypervisors.docker'
+
+        def call_the_resolver
+          fact_value = check_docker
+          Facter::ResolvedFact.new(FACT_NAME, fact_value)
+        end
+
+        def check_docker
+          info = Facter::Resolvers::DockerLxc.resolve(:hypervisor)
+          info.values.first if info && info.keys.first == :docker
+        end
+      end
+    end
+  end
+end

spec/facter/facts/linux/hypervisors_spec.rb → spec/facter/facts/linux/hypervisors/docker_spec.rb

@@ -1,16 +1,17 @@
 # frozen_string_literal: true
 
-describe Facts::Linux::Hypervisors do
+describe Facts::Linux::Hypervisors::Docker do
   describe '#call_the_resolver' do
-    subject(:fact) { Facts::Linux::Hypervisors.new }
+    subject(:fact) { Facts::Linux::Hypervisors::Docker.new }
 
     before do
       allow(Facter::Resolvers::DockerLxc).to \
         receive(:resolve).with(:hypervisor).and_return(hv)
     end
 
     context 'when resolver returns docker' do
-      let(:hv) { { 'docker' => { 'id' => 'testid' } } }
+      let(:hv) { { docker: { 'id' => 'testid' } } }
+      let(:value) { { 'id' => 'testid' } }
 
       it 'calls Facter::Resolvers::DockerLxc' do
         fact.call_the_resolver
@@ -19,21 +20,16 @@
 
       it 'returns virtual fact' do
         expect(fact.call_the_resolver).to be_an_instance_of(Facter::ResolvedFact).and \
-          have_attributes(name: 'hypervisors', value: hv)
+          have_attributes(name: 'hypervisors.docker', value: value)
       end
     end
 
     context 'when resolver returns lxc' do
-      let(:hv) { { 'lxc' => { 'name' => 'test_name' } } }
-
-      it 'calls Facter::Resolvers::DockerLxc' do
-        fact.call_the_resolver
-        expect(Facter::Resolvers::DockerLxc).to have_received(:resolve).with(:hypervisor)
-      end
+      let(:hv) { { lxc: { 'name' => 'test_name' } } }
 
       it 'returns virtual fact' do
         expect(fact.call_the_resolver).to be_an_instance_of(Facter::ResolvedFact).and \
-          have_attributes(name: 'hypervisors', value: hv)
+          have_attributes(name: 'hypervisors.docker', value: nil)
       end
     end
 
@@ -42,7 +38,17 @@
 
       it 'returns virtual fact as nil' do
         expect(fact.call_the_resolver).to be_an_instance_of(Facter::ResolvedFact).and \
-          have_attributes(name: 'hypervisors', value: hv)
+          have_attributes(name: 'hypervisors.docker', value: hv)
+      end
+    end
+
+    context 'when docker info is empty' do
+      let(:hv) { { docker: {} } }
+      let(:value) { {} }
+
+      it 'returns virtual fact as nil' do
+        expect(fact.call_the_resolver).to be_an_instance_of(Facter::ResolvedFact).and \
+          have_attributes(name: 'hypervisors.docker', value: value)
       end
     end
   end