Network Time Protocol

$ sudo dnf install chrony

$ oc debug node/$NODE_NAME

sh-4.4#

# chroot /host

$ sudo systemctl is-active chronyd

active

$ oc debug node/$NODE_NAME

sh-4.4#

# chroot /host

$ sudo systemctl is-active ntpd

active

---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 75-master-ntpd-enable
spec:
  config:
    ignition:
      version: 3.1.0
    systemd:
      units:
      - name: ntpd.service
        enabled: true

This will enable the ntpd service in all the nodes labeled with the "master" role.

Note that this needs to be done for each MachineConfigPool

For more information on how to configure nodes with the Machine Config Operator see the relevant documentation.

maxpoll 

server

pool

Note that if the remediation shipping with this content is being used, the MachineConfig shipped does not include reference NTP servers to point to. It is up to the admin to set these which will vary depending on the cluster's requirements.

The aforementioned remediation does include the directory /etc/chrony.d which would allow the creation of configuration files to set these servers.

pool 2.rhel.pool.ntp.org iburst

server 0.rhel.pool.ntp.org minpoll 4 maxpoll 10
server 1.rhel.pool.ntp.org minpoll 4 maxpoll 10
server 2.rhel.pool.ntp.org minpoll 4 maxpoll 10
server 3.rhel.pool.ntp.org minpoll 4 maxpoll 10

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 75-master-chrony-servers
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,pool%202.rhel.pool.ntp.org%20iburst%0A%0Aserver%200.rhel.pool.ntp.org%20minpoll%204%20maxpoll%2010%0Aserver%201.rhel.pool.ntp.org%20minpoll%204%20maxpoll%2010%0Aserver%202.rhel.pool.ntp.org%20minpoll%204%20maxpoll%2010%0Aserver%203.rhel.pool.ntp.org%20minpoll%204%20maxpoll%2010
        mode: 0600
        path: /etc/chrony.d/10-rhel-pool-and-servers.conf
        overwrite: true

MachineConfigPool

• if the system is configured to use the chronyd as the NTP daemon (the default), edit the file /etc/chrony.conf as follows,
• if the system is configured to use the ntpd as the NTP daemon, edit the file /etc/ntp.conf as documented below.

server ntpserver

Note that if the remediation shipping with this content is being used, the MachineConfig shipped does not include reference NTP servers to point to. It is up to the admin to set these which will vary depending on the cluster's requirements.

The aforementioned remediation does include the directory /etc/chrony.d which would allow the creation of configuration files to set these servers.

pool 2.rhel.pool.ntp.org iburst

server 0.rhel.pool.ntp.org minpoll 4 maxpoll 10
server 1.rhel.pool.ntp.org minpoll 4 maxpoll 10
server 2.rhel.pool.ntp.org minpoll 4 maxpoll 10
server 3.rhel.pool.ntp.org minpoll 4 maxpoll 10

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 75-master-chrony-servers
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,pool%202.rhel.pool.ntp.org%20iburst%0A%0Aserver%200.rhel.pool.ntp.org%20minpoll%204%20maxpoll%2010%0Aserver%201.rhel.pool.ntp.org%20minpoll%204%20maxpoll%2010%0Aserver%202.rhel.pool.ntp.org%20minpoll%204%20maxpoll%2010%0Aserver%203.rhel.pool.ntp.org%20minpoll%204%20maxpoll%2010
        mode: 0600
        path: /etc/chrony.d/10-rhel-pool-and-servers.conf
        overwrite: true

MachineConfigPool

• if the system is configured to use the chronyd as the NTP daemon (the default), edit the file /etc/chrony.conf as follows,
• if the system is configured to use the ntpd as the NTP daemon, edit the file /etc/ntp.conf as documented below.

server ntpserver

Note that if the remediation shipping with this content is being used, the MachineConfig shipped does not include reference NTP servers to point to. It is up to the admin to set these which will vary depending on the cluster's requirements.

The aforementioned remediation does include the directory /etc/chrony.d which would allow the creation of configuration files to set these servers.

pool 2.rhel.pool.ntp.org iburst

server 0.rhel.pool.ntp.org minpoll 4 maxpoll 10
server 1.rhel.pool.ntp.org minpoll 4 maxpoll 10
server 2.rhel.pool.ntp.org minpoll 4 maxpoll 10
server 3.rhel.pool.ntp.org minpoll 4 maxpoll 10

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 75-master-chrony-servers
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,pool%202.rhel.pool.ntp.org%20iburst%0A%0Aserver%200.rhel.pool.ntp.org%20minpoll%204%20maxpoll%2010%0Aserver%201.rhel.pool.ntp.org%20minpoll%204%20maxpoll%2010%0Aserver%202.rhel.pool.ntp.org%20minpoll%204%20maxpoll%2010%0Aserver%203.rhel.pool.ntp.org%20minpoll%204%20maxpoll%2010
        mode: 0600
        path: /etc/chrony.d/10-rhel-pool-and-servers.conf
        overwrite: true

MachineConfigPool

server <remote-server>

server ntpserver

server ntpserver