3.2.6 Network Time Service Requirements

As a clustering environment, Kubernetes requires that system time is synchronized across each node within the cluster. Typically, this can be achieved by installing and configuring an NTP daemon on each node. You can do this in the following way:

  1. Install the ntp package, if it is not already installed:

    # yum install ntp
  2. Edit the NTP configuration in /etc/ntp.conf. Your requirements may vary. If you are using DHCP to configure the networking for each node, it is possible to configure NTP servers automatically. If you have not got a locally configured NTP service that your systems can sync to, and your systems have Internet access, you can configure them to use the public pool.ntp.org service. See https://www.ntppool.org/.

  3. Ensure that NTP is enabled to restart at boot and that it is started before you proceed with your Kubernetes installation. For example:

    # systemctl start ntpd
    # systemctl enable ntpd

Note that systems running on Oracle Cloud Infrastructure are configured to use the chronyd time service by default, so there is no requirement to add or configure NTP if you are installing into an Oracle Cloud Infrastructure environment.

For information on configuring a Network Time Service, see Oracle® Linux 7: Administrator's Guide.