<def-group>
  <!-- Check that exactly one time synchronization service is active -->
  <definition class="compliance" id="{{{ rule_id }}}" version="1">
  {{{ oval_metadata("Ensure a Single Time Synchronization Service is in Use") }}}
    <criteria>
        <criterion comment="exactly one time synchronization service is active"
            test_ref="test_{{{ rule_id }}}_single_active_timesync"/>
    </criteria>
  </definition>

  <!-- Objects and states to identify active time synchronization services -->
  <linux:systemdunitproperty_object id="obj_{{{ rule_id }}}_timesync_services" version="1"
      comment="All active time synchronization services">
    <linux:unit operation="pattern match">^(chrony|systemd-timesyncd).service$</linux:unit>
    <linux:property>ActiveState</linux:property>
    <filter action="include">ste_{{{ rule_id }}}_timesync_services</filter>
  </linux:systemdunitproperty_object>

  <linux:systemdunitproperty_state id="ste_{{{ rule_id }}}_timesync_services" version="1">
    <linux:value>active</linux:value>
  </linux:systemdunitproperty_state>

  <!-- Count active time synchronization services -->
  <local_variable id="var_{{{ rule_id }}}_timesync_active_count" datatype="int" version="1"
                 comment="Number of currently active time synchronization services">
   <count>
     <regex_capture pattern="^active$">
       <object_component item_field="value" object_ref="obj_{{{ rule_id }}}_timesync_services"/>
     </regex_capture>
   </count>
  </local_variable>

  <!-- Test that count equals one -->
  <ind:variable_test id="test_{{{ rule_id }}}_single_active_timesync" version="1" check="all"
                     comment="Verify exactly one time synchronization service is active">
    <ind:object object_ref="obj_{{{ rule_id }}}_count"/>
    <ind:state state_ref="ste_{{{ rule_id }}}_count"/>
  </ind:variable_test>

  <ind:variable_object id="obj_{{{ rule_id }}}_count" version="1">
    <ind:var_ref>var_{{{ rule_id }}}_timesync_active_count</ind:var_ref>
  </ind:variable_object>

  <ind:variable_state id="ste_{{{ rule_id }}}_count" version="1">
    <ind:value operation="equals" datatype="int">1</ind:value>
  </ind:variable_state>
</def-group>
