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.

Production-Grade Container Orchestration

Production-Grade Container Orchestration

Synopsis Set the selector on a resource. Note that the new selector will overwrite the old selector if the resource had one prior to the invocation of 'set selector'. A selector must begin with a letter or number, and may contain letters, numbers, hyphens, dots, and underscores, up to 63 characters. If --resource-version is specified, then updates will use this resource version, otherwise the existing resource-version will be used. Note: currently selectors can only be set on Service objects.

Synopsis The Kubernetes API server validates and configures data for the api objects which include pods, services, replicationcontrollers, and others. The API Server services REST operations and provides the frontend to the cluster's shared state through which all other components interact. kube-apiserver [flags] Options --admission-control-config-file string File with admission control configuration. --advertise-address string The IP address on which to advertise the apiserver to members of the cluster. This address must be reachable by the rest of the cluster.

Synopsis Roll back to a previous rollout. kubectl rollout undo (TYPE NAME | TYPE/NAME) [flags] Examples # Roll back to the previous deployment kubectl rollout undo deployment/abc # Roll back to daemonset revision 3 kubectl rollout undo daemonset/abc --to-revision=3 # Roll back to the previous deployment with dry-run kubectl rollout undo --dry-run=server deployment/abc Options --allow-missing-template-keys     Default: true If true, ignore any errors in templates when a field or map key is missing in the template.

Production-Grade Container Orchestration

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.

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.

Use kubectl patch to update Kubernetes API objects in place. Do a strategic merge patch or a JSON merge patch.