Single-node Kubernetes Cluster

This project shows how to run and manage a single-node Kubernetes cluster using RancherOS and RKE.

Prerequisites:

Optional Hypervisor, e.g. Hyper-V
RKE
Helm
Kubectl

Setup RancherOS VM

Download RancherOS ISO from the Rancher website and setup the cloud-config.yml according to the docs.

From your VM, validate and install the cloud-config to disk:

sudo ros config validate -i ./cloud-config.yml
sudo ros install -c ./cloud-config.yml -d /dev/sda

Init/Update RKE cluster

(Optional) Get the RKE CLI configuration to upgrade an existing cluster:

kubectl --kubeconfig kube_config_cluster-minimal.yml -n kube-system get cm full-cluster-state -o json | jq -r .data.\"full-cluster-state\" | jq -r . > cluster-minimal.rkestate

Apply latest changes to cluster (etcd, control plane, worker):

rke up --config rke/config-minimal.yml

Setup Rancher Server

Create namespace:

kubectl --kubeconfig rke/kube_config_cluster-minimal.yml create namespace cattle-system

(Optional) Create self-signed cert:

openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout tls.key -out tls.crt -subj "/CN=<HOST>/O=<HOST>"

Note: See custom ingress tls configurations here

Add cert to Rancher ingress:

kubectl --kubeconfig rke/kube_config_cluster-minimal.yml -n cattle-system create secret tls tls-rancher-ingress \
  --cert=tls.crt \
  --key=tls.key

Install Rancher Server in Kubernetes cluster:

helm repo add rancher-stable https://releases.rancher.com/server-charts/stable
helm repo update
helm install --kubeconfig rke/kube_config_cluster-minimal.yml --namespace cattle-system -f helm/rancher-server/values.yaml rancher-server rancher-stable/rancher --version 2.4.3

Update existing instance

Modify configuration values in helm/rancher-server/values.yaml then apply changes: