.. _environment-ntp-controller:

Controller node
~~~~~~~~~~~~~~~

Perform these steps on the controller node.

Install and configure components
--------------------------------

1. Install the packages:

   .. only:: ubuntu or debian

      .. code-block:: console

         # apt install chrony

      .. end

   .. endonly

   .. only:: rdo

      .. code-block:: console

         # yum install chrony

      .. end

   .. endonly

   .. only:: obs

      .. code-block:: console

         # zypper install chrony

      .. end

   .. endonly

.. only:: ubuntu or debian

   2. Edit the ``/etc/chrony/chrony.conf`` file and add, change, or remove
      these keys as necessary for your environment:

      .. code-block:: shell

         server NTP_SERVER iburst

      .. end

      Replace ``NTP_SERVER`` with the hostname or IP address of a suitable more
      accurate (lower stratum) NTP server. The configuration supports multiple
      ``server`` keys.

      .. note::

         By default, the controller node synchronizes the time via a pool of
         public servers. However, you can optionally configure alternative
         servers such as those provided by your organization.

   3. To enable other nodes to connect to the chrony daemon on the controller node,
      add this key to the ``/etc/chrony/chrony.conf`` file:

      .. code-block:: shell

         allow 10.0.0.0/24

      .. end

   4. Restart the NTP service:

      .. code-block:: console

         # service chrony restart

      .. end

.. endonly

.. only:: rdo or obs

   2. Edit the ``/etc/chrony.conf`` file and add, change, or remove these
      keys as necessary for your environment:

      .. code-block:: shell

         server NTP_SERVER iburst

      .. end

      Replace ``NTP_SERVER`` with the hostname or IP address of a suitable more
      accurate (lower stratum) NTP server. The configuration supports multiple
      ``server`` keys.

      .. note::

         By default, the controller node synchronizes the time via a pool of
         public servers. However, you can optionally configure alternative
         servers such as those provided by your organization.

   3. To enable other nodes to connect to the chrony daemon on the controller node,
      add this key to the ``/etc/chrony.conf`` file:

      .. code-block:: shell

         allow 10.0.0.0/24

      .. end

      If necessary, replace ``10.0.0.0/24`` with a description of your subnet.

   4. Start the NTP service and configure it to start when the system boots:

      .. code-block:: console

         # systemctl enable chronyd.service
         # systemctl start chronyd.service

      .. end

.. endonly