Add shared-network configuration

manifests/init.pp

@@ -46,6 +46,7 @@
   Hash[String, Hash] $hosts = {},
   Variant[Array[String], Optional[String]] $includes = undef,
   String $config_comment = 'dhcpd.conf',
+  Optional[String] $shared_network = undef,
 ) inherits dhcp::params {
   # In case people set interface instead of interfaces work around
   # that. If they set both, use interfaces and the user is a unwise
@@ -157,6 +158,19 @@
     order   => '01',
   }
 
+  if $shared_network {
+    concat::fragment { 'dhcp.conf+69_shared':
+      target  => "${dhcp_dir}/dhcpd.conf",
+      content => "shared-network ${shared_network} {\n",
+      order   => '69',
+    }
+    concat::fragment { 'dhcp.conf+71_shared':
+      target  => "${dhcp_dir}/dhcpd.conf",
+      content => "}\n",
+      order   => '71',
+    }
+  }
+
   create_resources('dhcp::subnet', $subnets)
   create_resources('dhcp::pool', $pools)
   create_resources('dhcp::host', $hosts)

spec/acceptance/shared_spec.rb

@@ -0,0 +1,31 @@
+require 'spec_helper_acceptance'
+
+describe 'Simple installation' do
+  interface = 'eth0'
+  config_file = fact('os.family') == 'Archlinux' ? '/etc/dhcpd.conf' : '/etc/dhcp/dhcpd.conf'
+
+  it_behaves_like 'an idempotent resource' do
+    let(:manifest) do
+      <<-EOS
+      $interface = $facts['networking']['interfaces']['#{interface}']
+
+      class { 'dhcp':
+        interfaces     => ['#{interface}'],
+        shared_network => 'shared',
+      }
+
+      dhcp::pool { "default subnet":
+        network => $interface['network'],
+        mask    => $interface['netmask'],
+      }
+      EOS
+    end
+  end
+
+  it_behaves_like 'a DHCP server'
+
+  describe file(config_file) do
+    it { is_expected.to be_file }
+    its(:content) { should match %r{shared-network shared} }
+  end
+end

spec/classes/init_spec.rb

@@ -534,6 +534,20 @@
           it { is_expected.to compile.and_raise_error(%r{dnsupdateserver or nameservers parameter is required to enable ddns}) }
         end
       end
+
+      describe "with shared_network" do
+          let(:params) { super().merge(shared_network: "shared") }
+
+          let(:expected_content) do
+            <<~CONTENT
+              shared-network shared {
+            CONTENT
+          end
+
+          it do
+            is_expected.to contain_concat__fragment('dhcp.conf+69_shared').with_content(expected_content)
+          end
+      end
     end
   end
 end