K8S on KVM

Create create-vm.sh:

#!/bin/sh

dist='bionic'

if [ -z "$1" ] ;
then
 echo Specify a virtual-machine name.
 exit 1
fi

sudo virt-install \
--name $1 \
--ram 4096 \
--disk path=/mnt/A/images/$1.img,size=30 \
--vcpus 2 \
--os-type linux \
--os-variant ubuntu18.04 \
--network bridge:br0,model=virtio \
--location "http://gb.archive.ubuntu.com/ubuntu/dists/${dist}/main/installer-amd64/" \
--graphics vnc,listen=192.168.2.13 \
--noautoconsole \
--extra-args "ip=192.168.2.30::192.168.2.1:255.255.255.0:${1}.internal.stroila.net:eth0:none"

Run create-vm.sh

./create-vm.sh k8s-master

Get the vnc display

virsh vncdisplay k8s-master

Turn off swap (edit /etc/fstab) and comment out the line that says swap.

and...

swapoff -a

Set static ip

$ cat /etc/netplan/01-netcfg.yaml 
# This file describes the network interfaces available on your system
# For more information, see netplan(5).
network:
  version: 2
  renderer: networkd
  ethernets:
    ens3:
      dhcp4: no
      dhcp6: no
      addresses: [192.168.2.30/24, '2001:1::1/64']
      gateway4: 192.168.2.1
      nameservers:
        addresses: [192.168.2.1]

Configure the nodes

#!/bin/sh

sudo apt update \
  && sudo apt install -qy docker.io

systemctl enable docker.service

sudo apt install gnupg2 -y
  
sudo apt update \
  && sudo apt install -y apt-transport-https \
  && curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -


echo "deb http://apt.kubernetes.io/ kubernetes-xenial main" \
  | sudo tee -a /etc/apt/sources.list.d/kubernetes.list \
  && sudo apt update 
  
  sudo apt update \
  && sudo apt-get install -y \
  kubelet \
  kubeadm \
  kubernetes-cni

Clone the vm

virt-clone --original k8s-master --name k8s-w1 --auto-clone
virt-clone --original k8s-master --name k8s-w2 --auto-clone
virt-clone --original k8s-master --name k8s-w3 --auto-clone
...

Set the static ip and hostname on the clones

hostnamectl set-hostname k8s-w1.internal.stroila.net
...

Create the cluster. On the master node:

sudo kubeadm init

Copy of the Kube config:

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

Install networking

kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d '\n')"

To alter the private subnet that Weavenet uses for allocating IP addresses to Pods (containers):

curl -SL "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d '\n')&env.IPALLOC_RANGE=172.16.8.64/27" \
| kubectl apply -f -

To join the workers run on each worker:

kubeadm join 192.168.2.30:6443 --token jwm5ss.drp2ohpl53anl8r2 \
    --discovery-token-ca-cert-hash sha256:39196d23b782299298b374ef8ec9637a2a1a29be286d98b820c34a30d073d2a3

Now you can list the nodes:

$ kubectl get nodes 
NAME                              STATUS   ROLES    AGE     VERSION
k8s-master.internal.stroila.net   Ready    master   21m     v1.15.2
k8s-w1.internal.stroila.net       Ready    <none>   4m      v1.15.2
k8s-w2.internal.stroila.net       Ready    <none>   2m26s   v1.15.2
k8s-w3.internal.stroila.net       Ready    <none>   95s     v1.15.2

Reference

https://kubernetes.io/docs/tasks/access-application-cluster/web-ui-dashboard/

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