Prepare the VM

Change to root:

sudo su

Turn off swap: To do this, you will first need to turn it off directly …

swapoff -a

… then comment out the reference to swap in /etc/fstab. Start by editing the file:

nano /etc/fstab

Then comment out the appropriate line, as in:

# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/ubuntu-vg/ubuntu-lv during curtin installation
/dev/disk/by-id/dm-uuid-LVM-W0C3VzBJbs6WPOkDRZyucwwkYeHnydeaHiM0Ralee7dstLYLUp0P1LGH6yd3h7wo / ext4 defaults 0 0
# /boot was on /dev/sda2 during curtin installation
/dev/disk/by-uuid/f5e207f7-b282-4684-8966-8ddb1e765db2 /boot ext4 defaults 0 0
# /swap.img     none    swap    sw      0       0 <- this line

Now configure iptables to receive bridged network traffic. First edit the sysctl.conf file:

nano /etc/ufw/sysctl.conf

And add the following lines to the end:

net/bridge/bridge-nf-call-ip6tables = 1
net/bridge/bridge-nf-call-iptables = 1
net/bridge/bridge-nf-call-arptables = 1

Reboot so the changes take effect. Install ebtables and ethtool:

sudo su
apt-get install ebtables ethtool

Reboot once more.

Kubeadm install

Install Docker:

sudo su

apt-get update
apt-get install -y docker.io

Install HTTPS support components (if necessary):

apt-get update 
apt-get install -y apt-transport-https

Install Curl (if necessary):

apt-get install curl

Retrieve the key for the Kubernetes repo and add it to your key manager:

curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -

Add the kubernetes repo to your system.

cat <<EOF >/etc/apt/sources.list.d/kubernetes.list
deb http://apt.kubernetes.io/ kubernetes-xenial main
EOF

Actually install the three pieces you’ll need, kubeadm, kubelet, and kubectl:

apt-get update
apt-get install -y kubelet kubeadm kubectl

At this point you should have all the tools you need, so you should be ready to go ahead and actually deploy a k8s cluster.

Now that the Kubeadm installation is complete, we’ll go ahead and create a new cluster using kubeadm init. Part of this process is choosing a network provider, and there are several choices; we’ll use Calico for this kubeadm init example.

Create the actual cluster. For Calico, we need to add the –pod-network-cidr switch as command line arguments to kubeadm init, as in:

kubeadm init --pod-network-cidr=192.168.0.0/16

This will crank for a while, eventually giving you output something like this:

[init] Using Kubernetes version: v1.20.2
[preflight] Running pre-flight checks
    [WARNING Service-Docker]: docker service is not enabled, please run 'systemctl enable docker.service'
    [WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/
[preflight] Pulling images required for setting up a Kubernetes cluster
[preflight] This might take a minute or two, depending on the speed of your internet connection
[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'
.
.
.

Your Kubernetes control-plane has initialized successfully!

To start using your cluster, you need to run the following as a regular user:

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

Alternatively, if you are the root user, you can run:

  export KUBECONFIG=/etc/kubernetes/admin.conf

You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
  https://kubernetes.io/docs/concepts/cluster-administration/addons/

Then you can join any number of worker nodes by running the following on each as root:

kubeadm join 10.0.2.15:6443 --token ... \
    --discovery-token-ca-cert-hash sha256:...

Prepare your system for adding workloads, including the network plugin. Open a NEW terminal window and execute the commands kubeadm gave you:

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

Install the Tigera Calico operator and custom resource definitions. (from https://docs.projectcalico.org/getting-started/kubernetes/quickstart)

kubectl create -f https://docs.projectcalico.org/manifests/tigera-operator.yaml

Install Calico by creating the necessary custom resource.

kubectl create -f https://docs.projectcalico.org/manifests/custom-resources.yaml

Check to see if the pods are running:

kubectl get pods --all-namespaces

The pods will start up over a short period of time. Untaint the master so that it will be available for scheduling workloads:

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

Confirm that you now have a node in your cluster with the following command.

kubectl get nodes -o wide

It should return something like the following.

NAME        STATUS   ROLES                  AGE   VERSION   INTERNAL-IP   EXTERNAL-IP   OS-IMAGE             KERNEL-VERSION     CONTAINER-RUNTIME
maquiloca   Ready    control-plane,master   33m   v1.20.2   10.0.2.15     <none>        Ubuntu 18.04.5 LTS   5.4.0-42-generic   docker://19.3.6

Teardown

Drain the node

kubectl drain <node name> --delete-local-data --force --ignore-daemonsets

Revert changes made by kubeadm init

kubeadm reset

lucianozablocki/install-init-kubeadm.md

Prepare the VM

Kubeadm install

Teardown