Setup cluster with kubeadm

Disable swap for kubelet to work properly

swapoff -a

Install prerequisites

sudo apt-get update
sudo apt-get install -y apt-transport-https ca-certificates curl

sudo curl -fsSLo /usr/share/keyrings/kubernetes-archive-keyring.gpg https://packages.cloud.google.com/apt/doc/apt-key.gpg

echo "deb [signed-by=/usr/share/keyrings/kubernetes-archive-keyring.gpg] https://apt.kubernetes.io/ kubernetes-xenial main" | sudo tee /etc/apt/sources.list.d/kubernetes.list

sudo apt-get update
sudo apt-get install -y containerd conntrack socat kubelet kubeadm kubectl 

Kubelet 1.26 requires containerd 1.6.0 or later.

Initialise cluster

We are going to use cilium in place of kube-proxy https://docs.cilium.io/en/v1.12/gettingstarted/kubeproxy-free/

sudo kubeadm init --skip-phases=addon/kube-proxy

Set up kubectl

https://kubernetes.io/docs/tasks/tools/

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

For remote kubectl copy the config file to local machine

scp veh@192.168.1.12:/home/veh/.kube/config ~/.kube/config

(Optional) Remove taint for single node use

Get taints on nodes

kubectl get nodes -o json | jq '.items[].spec.taints'

Remove taint on master node to allow scheduling of all deployments

kubectl taint nodes --all node-role.kubernetes.io/control-plane-

Install Cilium as Container Network Interface (CNI)

kubectl kustomize --enable-helm infra/cilium | kubectl apply -f -

https://docs.cilium.io/en/stable/gettingstarted/k8s-install-default/

Install Cilium CLI

CILIUM_CLI_VERSION=$(curl -s https://raw.githubusercontent.com/cilium/cilium-cli/master/stable.txt)
CLI_ARCH=amd64
if [ "$(uname -m)" = "aarch64" ]; then CLI_ARCH=arm64; fi
curl -L --fail --remote-name-all https://github.com/cilium/cilium-cli/releases/download/${CILIUM_CLI_VERSION}/cilium-linux-${CLI_ARCH}.tar.gz{,.sha256sum}
sha256sum --check cilium-linux-${CLI_ARCH}.tar.gz.sha256sum
sudo tar xzvfC cilium-linux-${CLI_ARCH}.tar.gz /usr/local/bin
rm cilium-linux-${CLI_ARCH}.tar.gz{,.sha256sum}

Install Cilium

cilium install

Validate install

cilium status

MetalLB

For load balancing

https://metallb.universe.tf/installation/

kubectl apply -k infra/metallb

Sealed Secrets

Used to create encrypted secrets

kubectl apply -k infra/sealed-secrets

Be sure to store the generated sealed secret key in a safa place!

kubectl -n kube-system get secrets

NB!: There will be errors if you use my sealed secrets as you (hopefully) don't have the decryption key

Traefik

Install Traefik

kubectl kustomize --enable-helm infra/traefik | kubectl apply -f -

Port forward Traefik

Port forward Traefik ports in router from 8000 to 80 for http and 4443 to 443 for https. IP can be found with kubectl get svc.

Test-application

Generate secret

apiVersion: v1
kind: Secret
metadata:
  name: traefik-forward-auth-secrets
  namespace: whoami
type: Opaque
data:
  google-client-id: <...>
  google-client-secret: <...>
  secret: <...>

Deploy a test-application by running

kubectl apply -k apps/whoami

An unsecured test-application whoami should be available at https://test.${DOMAIN}. If you configured apps/whoami/traefik-forward-auth correctly a secured version should be available at https://whoami.${DOMAIN}

ArgoCD

ArgoCD is configured to bootstrap the rest of the cluster

kubectl apply -k infra/argocd

Get ArgoCD initial secret

kubectl -n argocd get secrets argocd-initial-admin-secret -o json | jq -r .data.password | base64 -d

Kubernetes Dashboard

An OIDC (traefik-forward-auth) protected Kubernetes Dashboard can be deployed using

kubectl apply -k infra/dashboard

Create a token

kubectl -n kubernetes-dashboard create token admin-user

ApplicationSets

Once you've tested everything get the ball rolling with

kubectl apply -k sets

Cleanup

kubectl drain gauss --delete-emptydir-data --force --ignore-daemonsets
sudo kubeadm reset
sudo iptables -F && sudo iptables -t nat -F && sudo iptables -t mangle -F && sudo iptables -X
sudo ipvsadm -C

Troubleshooting

Kubernetes 1.26 requires containerd 1.6.0 or later due to the removal of support for CRI version v1alpha2 (link).

Make sure that runc is properly configured in containerd.

NB: Make sure the correct containerd daemon is running. (Check the loaded containerd service definition as reported by systemctl status containerd) Follow https://github.com/containerd/containerd/blob/main/docs/getting-started.md for further instructions.

sudo cat /etc/containerd/config.toml

[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc]
runtime_path = "/usr/bin/runc"
runtime_type = "io.containerd.runc.v2"

Wrong containerd version

1.7.x doesn't work?

Sealed Secrets

Restart pod after applying master-key