(FACT-852) Support for systemd and systemd_version

This commit adds support for systemd and systemd_version facts.

lib/facter/systemd.rb

@@ -0,0 +1,39 @@
+# Fact: systemd
+#
+# Purpose: 
+#   Determine whether SystemD is the init system on the node
+#
+# Resolution:
+#   Check the name of the process 1 (ps -p 1)
+#
+# Caveats:
+#
+
+# Fact: systemd-version
+#
+# Purpose: 
+#   Determine the version of systemd installed
+#
+# Resolution:
+#  Check the output of systemctl --version
+#
+# Caveats:
+#
+
+Facter.add(:systemd) do
+  confine :kernel => :linux
+  setcode do
+    result = false
+    init_process_name = Facter::Core::Execution.exec('ps -p 1 -o comm=')
+    if init_process_name.eql? 'systemd'
+      result = true
+    end
+  end
+end
+
+Facter.add(:systemd_version) do
+  confine :systemd => true
+  setcode do
+    version = Facter::Core::Execution.exec("systemctl --version | grep 'systemd' | awk '{ print $2 }'")
+  end
+end

schema/facter.json

@@ -181,6 +181,8 @@
         "swapsize" : { "type": "string" },
         "swapsize_mb" : { "type": "string" },
         "system32" : { "type": "string" },
+        "systemd" : { "type": "boolean" },
+        "systemd_version" : { "type": "string" },
         "system_uptime" : { "type": "object",
           "properties" : {
             "seconds" : { "type": "integer" },