2.1.8 Ensure that the --make-iptables-util-chains argument is set to true

Information

Allow Kubelet to manage iptables.

Rationale:

Kubelets can automatically manage the required changes to iptables based on how you choose your networking options for the pods. It is recommended to let kubelets manage the changes to iptables. This ensures that the iptables configuration remains in sync with pods networking configuration. Manually configuring iptables with dynamic pod network configuration changes might hamper the communication between pods/containers and to the outside world. You might have iptables rules too restrictive or too open.

Solution

Edit the kubelet service file '/etc/systemd/system/kubelet.service.d/10-kubeadm.conf' on each worker node and remove the '--make-iptables-util-chains' argument from the 'KUBELET_SYSTEM_PODS_ARGS' variable.

Based on your system, restart the 'kubelet' service. For example:

systemctl daemon-reload
systemctl restart kubelet.service

Impact:

Kubelet would manage the iptables on the system and keep it in sync. If you are using any other iptables management solution, then there might be some conflicts.

See Also

https://workbench.cisecurity.org/files/2125

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-7(5), CSCv6|9

Plugin: Unix

Control ID: 46213d8a156937a51009ebc8e8d36777c23dd05112325204789b98eeeb8938a2