Since release v1.32, we introduced configurable version compatibility and emulation options to Kubernetes control plane components to make upgrades safer by providing more control and increasing the granularity of steps available to cluster administrators. Emulated Version The emulation option is set by the --emulated-version flag of control plane components. It allows the component to emulate the behavior (APIs, features, ...) of an earlier version of Kubernetes. When used, the capabilities available will match the emulated version:

Different ways to change the behavior of your Kubernetes cluster.

System component logs record events happening in cluster, which can be very useful for debugging. You can configure log verbosity to see more or less detail. Logs can be as coarse-grained as showing errors within a component, or as fine-grained as showing step-by-step traces of events (like HTTP access logs, pod state changes, controller actions, or scheduler decisions). Warning:In contrast to the command line flags described here, the log output itself does not fall under the Kubernetes API stability guarantees: individual log entries and their formatting may change from one release to the next!

This page shows how to enable and configure autoscaling of the DNS service in your Kubernetes cluster. 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. If you do not already have a cluster, you can create one by using minikube or you can use one of these Kubernetes playgrounds:

This page shows how to install and use Antrea CNI plugin on Kubernetes. For background on Project Antrea, read the Introduction to Antrea. Before you begin You need to have a Kubernetes cluster. Follow the kubeadm getting started guide to bootstrap one. Deploying Antrea with kubeadm Follow Getting Started guide to deploy Antrea for kubeadm. What's next Once your cluster is running, you can follow the Declare Network Policy to try out Kubernetes NetworkPolicy.

This page explains how to configure your DNS Pod(s) and customize the DNS resolution process in your cluster. 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. If you do not already have a cluster, you can create one by using minikube or you can use one of these Kubernetes playgrounds:

This page shows how to use Kube-router for NetworkPolicy. Before you begin You need to have a Kubernetes cluster running. If you do not already have a cluster, you can create one by using any of the cluster installers like Kops, Bootkube, Kubeadm etc. Installing Kube-router addon The Kube-router Addon comes with a Network Policy Controller that watches Kubernetes API server for any NetworkPolicy and pods updated and configures iptables rules and ipsets to allow or block traffic as directed by the policies.

Production-Grade Container Orchestration

kubectl is the Kubernetes cli version of a swiss army knife, and can do many things. While this Book is focused on using kubectl to declaratively manage applications in Kubernetes, it also covers other kubectl functions. Command Families Most kubectl commands typically fall into one of a few categories: Type Used For Description Declarative Resource Management Deployment and operations (e.g. GitOps) Declaratively manage Kubernetes workloads using resource configuration Imperative Resource Management Development Only Run commands to manage Kubernetes workloads using Command Line arguments and flags Printing Workload State Debugging Print information about workloads Interacting with Containers Debugging Exec, attach, cp, logs Cluster Management Cluster operations Drain and cordon Nodes Declarative Application Management The preferred approach for managing resources is through declarative files called resource configuration used with the kubectl Apply command.

If you configure a Service, you can select from any network protocol that Kubernetes supports. Kubernetes supports the following protocols with Services: SCTP TCP (the default) UDP When you define a Service, you can also specify the application protocol that it uses. This document details some special cases, all of them typically using TCP as a transport protocol: HTTP and HTTPS PROXY protocol TLS termination at the load balancer Supported protocols There are 3 valid values for the protocol of a port for a Service: