Create a production-quality Kubernetes cluster

Kubernetes objects are persistent entities in the Kubernetes system. Kubernetes uses these entities to represent the state of your cluster. Learn about the Kubernetes object model and how to work with these objects.

FEATURE STATE: Kubernetes v1.30 [beta] This page explains how user namespaces are used in Kubernetes pods. A user namespace isolates the user running inside the container from the one in the host. A process running as root in a container can run as a different (non-root) user in the host; in other words, the process has full privileges for operations inside the user namespace, but is unprivileged for operations outside the namespace.

Note: Dockershim has been removed from the Kubernetes project as of release 1.24. Read the Dockershim Removal FAQ for further details. You need to install a container runtime into each node in the cluster so that Pods can run there. This page outlines what is involved and describes related tasks for setting up nodes. Kubernetes 1.33 requires that you use a runtime that conforms with the Container Runtime Interface (CRI).

The Kubernetes API lets you query and manipulate the state of objects in Kubernetes. The core of Kubernetes' control plane is the API server and the HTTP API that it exposes. Users, the different parts of your cluster, and external components all communicate with one another through the API server.

This page provides an overview of best practices when it comes to enforcing Pod Security Standards. Using the built-in Pod Security Admission Controller FEATURE STATE: Kubernetes v1.25 [stable] The Pod Security Admission Controller intends to replace the deprecated PodSecurityPolicies. Configure all cluster namespaces Namespaces that lack any configuration at all should be considered significant gaps in your cluster security model. We recommend taking the time to analyze the types of workloads occurring in each namespace, and by referencing the Pod Security Standards, decide on an appropriate level for each of them.

Field selectors let you select Kubernetes objects based on the value of one or more resource fields. Here are some examples of field selector queries: metadata.name=my-service metadata.namespace!=default status.phase=Pending This kubectl command selects all Pods for which the value of the status.phase field is Running: kubectl get pods --field-selector status.phase=Running Note:Field selectors are essentially resource filters. By default, no selectors/filters are applied, meaning that all resources of the specified type are selected.

This page describes the lifecycle of a Pod. Pods follow a defined lifecycle, starting in the Pending phase, moving through Running if at least one of its primary containers starts OK, and then through either the Succeeded or Failed phases depending on whether any container in the Pod terminated in failure. Like individual application containers, Pods are considered to be relatively ephemeral (rather than durable) entities. Pods are created, assigned a unique ID (UID), and scheduled to run on nodes where they remain until termination (according to restart policy) or deletion.

Technology for packaging an application along with its runtime dependencies.

A Deployment manages a set of Pods to run an application workload, usually one that doesn't maintain state.