Create Cluster

Here is a brief overview of how you can create a simple functional cluster. Including prerequisites and step by step instructions .

3 minute read

How to create a working cluster?

Pre-requisites

maintenance packages installed?
network connection?
LIMAROOT set

Steps

create yaml file
create cluster with multiple nodes
add nodes to created cluster
delete nodes when needed

Once you have completed the KubeOps installation, you are ready to dive into the KubeOps-Platform.

How to use LIMA

Downloaded all maintenance packages? If yes, then you are ready to use LIMA for managing your Kubernetes clusters!

In the following sections we will walk you through a quick cluster setup and adding nodes.

So the first thing to do is to create a YAML file that contains the specifications of your cluster. Customize the file below according to your downloaded maintenance packages, e.g. the parameters kubernetesVersion, firewall, containerRuntime. Also adjust the other parameters like masterPassword, masterHost, apiEndpoint to your environment.

createCluster.yaml

apiVersion: lima/clusterconfig/v1alpha2
spec:
  clusterName: ExampleClusterName
  masterUser: root
  masterPassword: "myPassword"
  masterHost: 10.2.1.11
  kubernetesVersion: 1.22.2
  registry: registry1.kubernative.net/kubeops
  useInsecureRegistry: false
  ignoreFirewallError: false
  firewall: firewalld
  apiEndpoint: 10.2.1.11:6443
  serviceSubnet: 192.168.128.0/20
  podSubnet: 192.168.144.0/20
  debug: true
  logLevel: v
  systemCpu: 100m
  systemMemory: 100Mi
  sudo: false
  containerRuntime: crio
  pluginNetwork:
    type: weave
    parameters:
      weavePassword: re4llyS7ron6P4ssw0rd
  auditLog: false
  serial: 1
  seLinuxSupport: true

Most of these parameters are optional and can be left out. If you want to know more about each parameter please refer to our Full Documentation

Set up a single node cluster

To set up a single node cluster we need our createCluster.yaml file from above.
Run the create cluster command on the admin node to create a cluster with one node.

lima create cluster -f createCluster.yaml

Done! LIMA is setting up your Kubernetes cluster. In a few minutes you have set up a regular single master cluster.

If LIMA is successfully finished you can check with kubectl get nodes your Kubernetes single node cluster.

It looks very alone and sad right? Jump to the next section to add some friends to your cluster!

Optional step

The master node which you used to set up your cluster is only suitable as an example installation or for testing. To use this node for production workloads remove the taint from the master node.

kubectl taint nodes --all node-role.kubernetes.io/master-

Add nodes to your cluster

Let’s give your single node cluster some friends. What we need for this is another YAML file. We can call the YAML file whatever we want - we call it addNode.yaml.

addNode.yaml

apiVersion: lima/nodeconfig/v1alpha1
clusterName: ExampleClusterName
spec: 
  masters:
  - host: 10.2.1.12
    user: root
    password: "myPassword"
  workers:
  - host: 10.2.1.13 #IP-address of the node you want to add
    user: root
    password: "myPassword"

We do not need to pull any other maintenance packages. We already did that and are using the same specifications from our single node cluster. The only thing to do is to use the create nodes command

lima create nodes -f addNode.yaml

Done! LIMA adds the nodes to your single node cluster. After LIMA is finished check again with kubectl get nodes the state of your Kubernetes cluster. Your master node should not be alone anymore!