This page explains how to configure the kubelet's cgroup driver to match the container runtime cgroup driver for kubeadm clusters. Before you begin You should be familiar with the Kubernetes container runtime requirements. Configuring the container runtime cgroup driver The Container runtimes page explains that the systemd driver is recommended for kubeadm based setups instead of the kubelet's default cgroupfs driver, because kubeadm manages the kubelet as a systemd service.

In a Kubernetes cluster, a node can be shut down in a planned graceful way or unexpectedly because of reasons such as a power outage or something else external. A node shutdown could lead to workload failure if the node is not drained before the shutdown. A node shutdown can be either graceful or non-graceful. Graceful node shutdown The kubelet attempts to detect node system shutdown and terminates pods running on the node.

Define a range of valid memory resource limits for a namespace, so that every new Pod in that namespace falls within the range you configure.

Node affinity is a property of Pods that attracts them to a set of nodes (either as a preference or a hard requirement). Taints are the opposite -- they allow a node to repel a set of pods. Tolerations are applied to pods. Tolerations allow the scheduler to schedule pods with matching taints. Tolerations allow scheduling but don't guarantee scheduling: the scheduler also evaluates other parameters as part of its function.

Namespaces can be labeled to enforce the Pod Security Standards. The three policies privileged, baseline and restricted broadly cover the security spectrum and are implemented by the Pod Security admission controller. Before you begin Pod Security Admission was available by default in Kubernetes v1.23, as a beta. From version 1.25 onwards, Pod Security Admission is generally available. To check the version, enter kubectl version. Requiring the baseline Pod Security Standard with namespace labels This manifest defines a Namespace my-baseline-namespace that:

This page shows how to use a Volume to communicate between two Containers running in the same Pod. See also how to allow processes to communicate by sharing process namespace between containers. Before you begin You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. It is recommended to run this tutorial on a cluster with at least two nodes that are not acting as control plane hosts.

Kubernetes core components such as the API server, scheduler, and controller-manager run on a control plane node. However, add-ons must run on a regular cluster node. Some of these add-ons are critical to a fully functional cluster, such as metrics-server, DNS, and UI. A cluster may stop working properly if a critical add-on is evicted (either manually or as a side effect of another operation like upgrade) and becomes pending (for example when the cluster is highly utilized and either there are other pending pods that schedule into the space vacated by the evicted critical add-on pod or the amount of resources available on the node changed for some other reason).

This page provides an example of how to provision and configure swap memory on a Kubernetes node using kubeadm. Objectives Provision swap memory on a Kubernetes node using kubeadm. Learn to configure both encrypted and unencrypted swap. Learn to enable swap on boot. Before you begin You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. It is recommended to run this tutorial on a cluster with at least two nodes that are not acting as control plane hosts.

The Kubernetes model for connecting containers Now that you have a continuously running, replicated application you can expose it on a network. Kubernetes assumes that pods can communicate with other pods, regardless of which host they land on. Kubernetes gives every pod its own cluster-private IP address, so you do not need to explicitly create links between pods or map container ports to host ports. This means that containers within a Pod can all reach each other's ports on localhost, and all pods in a cluster can see each other without NAT.

Understand how to protect traffic within your cluster using Transport Layer Security (TLS).