K8S Bootstrap

Base OS system

Choice is made on auto-updating Fedora CoreOS.

Last version shall be available from the official web site: https://getfedora.org/en/coreos/download

Produce ignition file

Fedora CoreOS need to use ignition to setup the system at first boot.

You can write a FCCS, then convert it into ignition, using the converter. Please cf. to Producing an Ignition File

podman pull quay.io/coreos/fcct:release
podman run -i --rm quay.io/coreos/fcct:release --pretty --strict <exampel.fcc> example.ign

coreos-install

If you choose to boot from a vanilla image disk, you shall have to install the system on disk using the coreos-install.

After autologin, use this kind of command line.

sudo coreos-install /dev/sda --ignition-url https://pi.genesis.workoutperf.com/ignition/node.ign

Prepare system to install Kubernetes

After install and a reboot, you shall be able to connect through SSH. Copy the setup_system.sh file, and execute it on the fresh OS.

It will download requirements, make some system config and install kubeadm, kubelet and kubectl and the system.

Install Kubernetes

If you want to setup a new cluster, you shall use the cluster-config.yaml

RECOMMANDED, launch preflight checks

sudo kubeadm init phase preflight --config cluster-config.yaml

if no error, then launch for real

sudo kubeadm init --config cluster-config.yaml

Untaint master nodes

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

Install network

For now with use Calico. Cf. Calico Documentation

The installation for less than 50 nodes shall be enougth

 curl -fsSL https://docs.projectcalico.org/manifests/calico.yaml | sed -e "s/\/usr\/libexec/\/opt\/libexec/g" | kubectl create -f -

REMARQS: as Fedora COREOS mount the /usr in readonly, the path shall be changed

Wait for calico node become ready.

Install load-balancer

Install metalLB.

See what changes would be made, returns nonzero returncode if different

kubectl get configmap kube-proxy -n kube-system -o yaml | \
sed -e "s/strictARP: false/strictARP: true/" | \
sed -e "s/mode: \"\"/mode: \"ipvs\"/" | \
kubectl diff -f - -n kube-system

Actually apply the changes, returns nonzero returncode on errors only

kubectl get configmap kube-proxy -n kube-system -o yaml | \
sed -e "s/strictARP: false/strictARP: true/" | \
sed -e "s/mode: \"\"/mode: \"ipvs\"/" | \
kubectl apply -f - -n kube-system

Create a dedicated namespace, typicaly metallb-system and apply Kustomization of metalLB.

kubectl create namespace metallb-system
kubectl create -n metallb-system -k network/metallb/deploy

Install Cert-Manager

Retrieve last version

git clone --depth=1 --branch=v1.0.4 https://github.com/jetstack/cert-manager.git network/cert-manager/cert-manager

WARNING: You shall need to update chart version and appVersion before install. Edit with the expected version of branch extracted, in network/cert-manager/cert-manager/deploy/charts/cert-manager/Chart.yaml

apiVersion: v1
name: cert-manager
# The version and appVersion fields are set automatically by the release tool
version: v1.0.4
appVersion: v1.0.4
description: A Helm chart for cert-manager
home: https://github.com/jetstack/cert-manager
icon: https://raw.githubusercontent.com/jetstack/cert-manager/master/logo/logo.png
keywords:
  - cert-manager
  - kube-lego
  - letsencrypt
  - tls
sources:
  - https://github.com/jetstack/cert-manager
maintainers:
  - name: munnerz
    email: [email protected]

Edit the config in network/cert-manager/config.yaml

installCRDs: true

prometheus:
  enabled: false

create the cert-manager namespace, and install with Helm.

kubectl create namespace cert-manager
helm install -f network/cert-manager/config.yaml -n cert-manager cert-manager network/cert-manager/cert-manager/deploy/charts/cert-manager

Install Ingress (Treafik)

Retrieve last helm chart:

git clone --depth=1 --branch=master https://github.com/traefik/traefik-helm-chart network/traefik/traefik-helm-chart

Edit the config in network/traefik/config.yaml

ingressClass:
  enabled: true
  isDefaultClass: true

providers:
  kubernetesCRD:
    enabled: true

logs:
  general:
    level: INFO

ports:
  #web:
  #  redirectTo: websecure
  websecure:
    tls:
      enabled: true
      domains:
        - main: edge.fcos-k8s-single.genesis.workoutperf.com
          sans: 
            - traefik.edge.fcos-k8s-single.genesis.workoutperf.com
            - traefik.edge.fcos-k8s-single

service:
  spec:
    loadBalancerIP: "192.168.1.60"

create the traefik namespace, and install with Helm.

kubectl create namespace traefik-system
helm install -f network/traefik/config.yaml -n traefik-system traefik network/traefik/traefik-helm-chart/traefik