Kubernetes cluster

A Vagrant script for setting up a barebones Kubernetes cluster with a load-balancer and dynamic provisioner using Kubeadm.

Pre-requisites

• Vagrant 2.1.4+
• Virtualbox 5.2.18+

Start the Base Cluster

Run the following command using CMD/Powershell in the dir where your Vagrantfile lives.

vagrant up

• When this command finishes you will have (4) running VMs joined together as a K8s cluster.
• If more than three worker nodes are required, you can edit the servers array in the Vagrantfile

servers = [
    {
        :name => "k8s-node3",
        :type => "node",
        :box => "ubuntu/bionic64",
        :eth1 => "192.168.205.13",
        :mem => "2048",
        :cpu => "2"
    }
]

• As you can see above, you can also configure a static IP address, memory and CPU in the servers array.

Check Cluster Health and Update Admin Service Account

PS C:\users\djx\Documents\GitHub\kubernetes-cluster> vagrant ssh k8s-head
Welcome to Ubuntu 18.04.1 LTS (GNU/Linux 4.15.0-38-generic x86_64)
 
<snip output>

vagrant@k8s-head:~$ kubectl cluster-info
Kubernetes master is running at https://192.168.205.10:6443
KubeDNS is running at https://192.168.205.10:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy
 
To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.
 
vagrant@k8s-head:~$ kubectl get nodes
NAME         STATUS   ROLES    AGE   VERSION
k8s-head     Ready    master   14m   v1.14.2
k8s-node-1   Ready    <none>   10m   v1.14.2
k8s-node-2   Ready    <none>   5m    v1.14.2
k8s-node-3   Ready    <none>   34s   v1.14.2
 
vagrant@k8s-head:~$ kubectl create clusterrolebinding default-admin --clusterrole cluster-admin --serviceaccount=default:default
clusterrolebinding.rbac.authorization.k8s.io/default-admin created

Install MetalLB Load Balancer

You can also use the included YAML files to pull and deploy MetalLB, a load balancer that will distribute IPs in a given range. This has a lot more functionality than we are using, and you can see the other examples at the project page.

vagrant@k8s-head:~$ kubectl apply -f https://raw.githubusercontent.com/jprdonnelly/kubernetes-cluster/master/metallb/metallb.yaml
namespace/metallb-system created
serviceaccount/controller created
serviceaccount/speaker created
clusterrole.rbac.authorization.k8s.io/metallb-system:controller created
clusterrole.rbac.authorization.k8s.io/metallb-system:speaker created
role.rbac.authorization.k8s.io/config-watcher created
clusterrolebinding.rbac.authorization.k8s.io/metallb-system:controller created
clusterrolebinding.rbac.authorization.k8s.io/metallb-system:speaker created
rolebinding.rbac.authorization.k8s.io/config-watcher created
daemonset.apps/speaker created
deployment.apps/controller created
 
vagrant@k8s-head:~$ kubectl apply -f https://raw.githubusercontent.com/jprdonnelly/kubernetes-cluster/master/metallb/layer-2.yaml
configmap/config created

Install NFS Provisioner

vagrant@k8s-head:~$ kubectl label nodes k8s-node1 role=nfs
node/k8s-node1 labeled
 
vagrant@k8s-head:~$ kubectl apply -f https://raw.githubusercontent.com/jprdonnelly/kubernetes-cluster/master/nfs-provisioner/nfs-deployment.yaml
service/nfs-provisioner created
deployment.apps/nfs-provisioner created
 
vagrant@k8s-head:~$ kubectl apply -f https://raw.githubusercontent.com/jprdonnelly/kubernetes-cluster/master/nfs-provisioner/nfs-class.yaml
storageclass.storage.k8s.io/nfs-dynamic created
vagrant@k8s-head:~$ kubectl get svc
NAME              TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)                              AGE
kubernetes        ClusterIP   10.96.0.1        <none>        443/TCP                              18m
nfs-provisioner   ClusterIP   10.109.234.184   <none>        2049/TCP,20048/TCP,111/TCP,111/UDP   11s
 
vagrant@k8s-head:~$ kubectl patch storageclass nfs-dynamic -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"true"}}}'
storageclass.storage.k8s.io/nfs-dynamic patched
 
vagrant@k8s-head:~$ kubectl apply -f https://raw.githubusercontent.com/jprdonnelly/kubernetes-cluster/master/qseok/nfs-vol-pvc.yaml
persistentvolumeclaim/qseok-vol created
 
vagrant@k8s-head:~$ kubectl get pvc
NAME        STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
qseok-vol   Bound    pvc-60cd4de4-e372-11e8-84e2-02c44c503abe   5Gi        RWX            nfs-dynamic    38s
 
vagrant@k8s-head:~$ kubectl get pv
NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM               STORAGECLASS   REASON   AGE
pvc-60cd4de4-e372-11e8-84e2-02c44c503abe   5Gi        RWX            Delete           Bound    default/qseok-vol   nfs-dynamic

Clean-up

Execute the following command to remove the virtual machines created for the Kubernetes cluster.

vagrant destroy -f

You can destroy individual machines by

vagrant destroy k8s-node3 -f

Licensing

Apache License, Version 2.0.