Install Kubernetes

This is how to install a Kubernetes cluster with kubeadm.

Installation instructions

Bootstrap the cluster

IP=your-ip-address

wget -O install.sh https://raw.githubusercontent.com/peterconnects/kubernetes-scripts/master/install.sh 
chmod u=rwx install.sh

sudo ./install.sh kubelab $IP  2>&1 | tee outfile

Reset

sudo kubeadm reset --force && \
  sudo rm -rf kubeadm-config.yaml helm* install.sh && \
  sudo rm -rf /tmp/installed
sudo rm -rf ~/.kube && sudo rm -rf ~/.helm

Increase disksize for the Vagrantbox

Thanks to this plugin: https://github.com/sprotheroe/vagrant-disksize.

vagrant plugin install vagrant-disksize

Example:

Vagrant.configure('2') do |config|
  config.vm.box = 'ubuntu/xenial64'
  config.disksize.size = '50GB'
end

Network instructions for the Vagrant box(es)

Edit the Vagrantfile. Adjust the variables on top to match your IP config and cluster- and SAN names**:

• to find a free IP address in your subnet, type e.g. nmap -sP 192.168.1.0/24
• to find your bridge interface, type net add
• to find your Gateway type netstat -rn or ip r
• to find your DNS type nmcli dev show | grep DNS

In Windows ipconfig /all will do the trick.

Then bootstrap the cluster like so:

vagrant up

What is installed

Kubernetes cluster

Kubernetes is installed with the following customizations:

• The ingress controller will also listen to 1433 (mssql). See the configmap.
• The ingress controller is set to use hostnetwork = true to have it work on a single node bare metal cluster
• The dashboard is set to use NodePort to be able to browse to it via its TCP port instead of using kubectl proxy.

Software and tools

The following packages are installed on top of Ubuntu 18.04.03 LTS:

• Build tools
• Misc tools like vim, wget, curl, git, tcpdump, nmap
• Docker
• Kubeadm
• Kubelet
• Flannel
• Nginx Ingress controller
• Kubernetes Dashboard
• Helm
• Azure CLI
• Mozilla SOPS

Ingress & SQL Server on a single node cluster without a load balancer

What if we want to expose MSSQL over port 1433?

We need to set the hostNetwork to true, as documented here:
https://kubernetes.github.io/ingress-nginx/deploy/baremetal/#via-the-host-network

We need to expose the extra TCP port like so:
https://kubernetes.github.io/ingress-nginx/user-guide/exposing-tcp-udp-services

The tcp service configmap looks like so:

kind: ConfigMap
apiVersion: v1
metadata:
  name: tcp-services
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
data:
  1433: "default/mssql-service:1433"

When deploying mssql, we need to expose mssql via a service like so:

apiVersion: v1
kind: Service
metadata:
  name: mssql-service
  labels:
    release: {{ .Release.Name }}-mssql
spec:
  selector:
    app: mssql
  ports:
    - protocol: TCP
      port: 1433
      targetPort: 1433
  type: NodePort