This tutorial shows you how to run Apache Cassandra on Kubernetes. Cassandra, a database, needs persistent storage to provide data durability (application state). In this example, a custom Cassandra seed provider lets the database discover new Cassandra instances as they join the Cassandra cluster. StatefulSets make it easier to deploy stateful applications into your Kubernetes cluster. For more information on the features used in this tutorial, see StatefulSet. Note:Cassandra and Kubernetes both use the term node to mean a member of a cluster.

This command initializes a new Kubernetes node and joins it to the existing cluster. Run this on any machine you wish to join an existing cluster Synopsis When joining a kubeadm initialized cluster, we need to establish bidirectional trust. This is split into discovery (having the Node trust the Kubernetes Control Plane) and TLS bootstrap (having the Kubernetes Control Plane trust the Node). There are 2 main schemes for discovery.

The status of a node in Kubernetes is a critical aspect of managing a Kubernetes cluster. In this article, we'll cover the basics of monitoring and maintaining node status to ensure a healthy and stable cluster. Node status fields A Node's status contains the following information: Addresses Conditions Capacity and Allocatable Info You can use kubectl to view a Node's status and other details: kubectl describe node <insert-node-name-here> Each section of the output is described below.

kubeadm join phase enables you to invoke atomic steps of the join process. Hence, you can let kubeadm do some of the work and you can fill in the gaps if you wish to apply customization. kubeadm join phase is consistent with the kubeadm join workflow, and behind the scene both use the same code. kubeadm join phase phase Synopsis Use this command to invoke single phase of the "join" workflow

To allow Kubernetes workloads to use swap, on a Linux node, you must disable the kubelet's default behavior of failing when swap is detected, and specify memory-swap behavior as LimitedSwap: The available choices for swap behavior are: NoSwap (default) Workloads running as Pods on this node do not and cannot use swap. However, processes outside of Kubernetes' scope, such as system daemons (including the kubelet itself!) can utilize swap. This behavior is beneficial for protecting the node from system-level memory spikes, but it does not safeguard the workloads themselves from such spikes.

kubeadm upgrade is a user-friendly command that wraps complex upgrading logic behind one command, with support for both planning an upgrade and actually performing it. kubeadm upgrade guidance The steps for performing an upgrade using kubeadm are outlined in this document. For older versions of kubeadm, please refer to older documentation sets of the Kubernetes website. You can use kubeadm upgrade diff to see the changes that would be applied to static pod manifests.

Production-Grade Container Orchestration

Synopsis Set a cluster entry in kubeconfig. Specifying a name that already exists will merge new fields on top of existing values for those fields. kubectl config set-cluster NAME [--server=server] [--certificate-authority=path/to/certificate/authority] [--insecure-skip-tls-verify=true] [--tls-server-name=example.com] Examples # Set only the server field on the e2e cluster entry without touching other values kubectl config set-cluster e2e --server=https://1.2.3.4 # Embed certificate authority data for the e2e cluster entry kubectl config set-cluster e2e --embed-certs --certificate-authority=~/.

Synopsis Create a role with single rule. kubectl create role NAME --verb=verb --resource=resource.group/subresource [--resource-name=resourcename] [--dry-run=server|client|none] Examples # Create a role named "pod-reader" that allows user to perform "get", "watch" and "list" on pods kubectl create role pod-reader --verb=get --verb=list --verb=watch --resource=pods # Create a role named "pod-reader" with ResourceName specified kubectl create role pod-reader --verb=get --resource=pods --resource-name=readablepod --resource-name=anotherpod # Create a role named "foo" with API Group specified kubectl create role foo --verb=get,list,watch --resource=rs.

Synopsis Create a cluster role binding for a particular cluster role. kubectl create clusterrolebinding NAME --clusterrole=NAME [--user=username] [--group=groupname] [--serviceaccount=namespace:serviceaccountname] [--dry-run=server|client|none] Examples # Create a cluster role binding for user1, user2, and group1 using the cluster-admin cluster role kubectl create clusterrolebinding cluster-admin --clusterrole=cluster-admin --user=user1 --user=user2 --group=group1 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. Only applies to golang and jsonpath output formats.