Kubernetes cluster

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

Pre-requisites

• Vagrant 2.2.4+

• Virtualbox 6+

• Do NOT install the proprietary extension pack from Oracle - it is non-free and they have started to track IP addresses and demand license fees.

• Do NOT use Powershell ISE - when attempting to SSH, ISE will lockup. Please use CMD/Powershell or a *nix OS.

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

PS> 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   68m   v1.15.2
k8s-nfs     Ready    <none>   53m   v1.15.2
k8s-node1   Ready    <none>   65m   v1.15.2
k8s-node2   Ready    <none>   61m   v1.15.2

Install Helm

vagrant@k8s-master:~$ curl -LO https://git.io/get_helm.sh
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
100  7034  100  7034    0     0  40425      0 --:--:-- --:--:-- --:--:-- 40425
vagrant@k8s-master:~$ chmod +x ./get_helm.sh
vagrant@k8s-master:~$ ./get_helm.sh --version v2.14.3
Downloading https://get.helm.sh/helm-v2.14.3-linux-amd64.tar.gz
Preparing to install helm and tiller into /usr/local/bin
helm installed into /usr/local/bin/helm
tiller installed into /usr/local/bin/tiller
Run 'helm init' to configure helm.
vagrant@k8s-master:~$ helm init --service-account tiller --wait
Creating /home/vagrant/.helm
Creating /home/vagrant/.helm/repository
Creating /home/vagrant/.helm/repository/cache
Creating /home/vagrant/.helm/repository/local
Creating /home/vagrant/.helm/plugins
Creating /home/vagrant/.helm/starters
Creating /home/vagrant/.helm/cache/archive
Creating /home/vagrant/.helm/repository/repositories.yaml
Adding stable repo with URL: https://kubernetes-charts.storage.googleapis.com
Adding local repo with URL: http://127.0.0.1:8879/charts
$HELM_HOME has been configured at /home/vagrant/.helm.

Tiller (the Helm server-side component) has been installed into your Kubernetes Cluster.

Please note: by default, Tiller is deployed with an insecure 'allow unauthenticated users' policy.
To prevent this, run `helm init` with the --tiller-tls-verify flag.
For more information on securing your installation see: https://docs.helm.sh/using_helm/#securing-your-helm-installation
vagrant@k8s-master:~$

Install NFS Provisioner

vagrant@k8s-head:~$ kubectl taint nodes k8s-nfs key=value:NoSchedule
node/k8s-nfs tainted

vagrant@k8s-head:~$ kubectl apply -f \
https://raw.githubusercontent.com/jprdonnelly/kubernetes-cluster/master/nfs-provisioner/nfs-helm-pvc.yaml
persistentvolume/nfs-provisioner-vol created

vagrant@k8s-head:~$ helm install -n nfs stable/nfs-server-provisioner \
-f https://raw.githubusercontent.com/jprdonnelly/kubernetes-cluster/master/nfs-provisioner/nfs-helm-values.yaml
NAME:   nfs
LAST DEPLOYED: Mon Sep  9 12:59:26 2019
NAMESPACE: default
STATUS: DEPLOYED

RESOURCES:
==> v1/ClusterRole
NAME                        AGE
nfs-nfs-server-provisioner  1s

==> v1/ClusterRoleBinding
NAME                        AGE
nfs-nfs-server-provisioner  1s

==> v1/Pod(related)
NAME                          READY  STATUS   RESTARTS  AGE
nfs-nfs-server-provisioner-0  0/1    Pending  0         1s

==> v1/Service
NAME                        TYPE       CLUSTER-IP     EXTERNAL-IP  PORT(S)                                 AGE
nfs-nfs-server-provisioner  ClusterIP  10.105.237.23  <none>       2049/TCP,20048/TCP,51413/TCP,51413/UDP  1s

==> v1/ServiceAccount
NAME                        SECRETS  AGE
nfs-nfs-server-provisioner  1        1s

==> v1/StorageClass
NAME                   PROVISIONER            AGE
nfs-dynamic (default)  provisioner.local/nfs  1s

==> v1beta2/StatefulSet
NAME                        READY  AGE
nfs-nfs-server-provisioner  0/1    1s


NOTES:
The NFS Provisioner service has now been installed.

A storage class named 'nfs-dynamic' has now been created
and is available to provision dynamic volumes.

You can use this storageclass by creating a `PersistentVolumeClaim` with the
correct storageClassName attribute. For example:

    ---
    kind: PersistentVolumeClaim
    apiVersion: v1
    metadata:
      name: test-dynamic-volume-claim
    spec:
      storageClassName: "nfs-dynamic"
      accessModes:
        - ReadWriteOnce
      resources:
        requests:
          storage: 100Mi

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 configured

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.