This documentation is about investigating and diagnosing kubectl related issues. If you encounter issues accessing kubectl or connecting to your cluster, this document outlines various common scenarios and potential solutions to help identify and address the likely cause. Before you begin You need to have a Kubernetes cluster. You also need to have kubectl installed - see install tools Verify kubectl setup Make sure you have installed and configured kubectl correctly on your local machine.

To scale an application and provide a reliable service, you need to understand how the application behaves when it is deployed. You can examine application performance in a Kubernetes cluster by examining the containers, pods, services, and the characteristics of the overall cluster. Kubernetes provides detailed information about an application's resource usage at each of these levels. This information allows you to evaluate your application's performance and where bottlenecks can be removed to improve overall performance.

This page shows how to write and read a Container termination message. Termination messages provide a way for containers to write information about fatal events to a location where it can be easily retrieved and surfaced by tools like dashboards and monitoring software. In most cases, information that you put in a termination message should also be written to the general Kubernetes logs. Before you begin You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster.

This page shows you how to run a single-instance stateful application in Kubernetes using a PersistentVolume and a Deployment. The application is MySQL. Objectives Create a PersistentVolume referencing a disk in your environment. Create a MySQL Deployment. Expose MySQL to other pods in the cluster at a known DNS name. Before you begin You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster.

This page shows how to define dependent environment variables for a container in a Kubernetes Pod. 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 a Pod can use environment variables to expose information about itself to containers running in the Pod, using the downward API. You can use environment variables to expose Pod fields, container fields, or both. In Kubernetes, there are two ways to expose Pod and container fields to a running container: Environment variables, as explained in this task Volume files Together, these two ways of exposing Pod and container fields are called the downward API.

In this example, you will run a Job in Indexed completion mode configured such that the pods created by the Job can communicate with each other using pod hostnames rather than pod IP addresses. Pods within a Job might need to communicate among themselves. The user workload running in each pod could query the Kubernetes API server to learn the IPs of the other Pods, but it's much simpler to rely on Kubernetes' built-in DNS resolution.

This page shows how to use kubectl to list all of the Container images for Pods running in a 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 perform a rollback on a DaemonSet. 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:

FEATURE STATE: Kubernetes v1.21 [stable] This page shows how to limit the number of concurrent disruptions that your application experiences, allowing for higher availability while permitting the cluster administrator to manage the clusters nodes. Before you begin Your Kubernetes server must be at or later than version v1.21. To check the version, enter kubectl version. You are the owner of an application running on a Kubernetes cluster that requires high availability.