Deploy Rancher Kubernetes Engine

Why use Rancher to deploy a Kubernetes Cluster?

RKE is more configurable than kubeadm, which requires manual configuration of several components, such as kube-dns, coredns, flannel, and storageClass. Upgrading can also be challenging, particularly in mixed-OS environments like my setup, which has servers running Ubuntu 20.04.3 LTS and Centos 7. Rancher makes it more convenient to manage these differences. Because all rancher’s k8s services will run in Docker.

Moreover, Rancher configures each node using ssh, eliminating the need to add worker nodes individually to the master node.

This is a RKE example config cluster.yml.

nodes:
    - address: 192.168.1.109
      user: node
      role:
        - controlplane
        - etcd
        - worker
    - address: 192.168.1.105
      user: node
      role:
        - worker
      ssh_key_path: /home/node/.ssh/udoo
      labels:
        app: ingress

cluster_name: mycluster
ignore_docker_version: false
ssh_key_path: /home/node/.ssh/rke_rsa
ssh_cert_path: /home/node/.ssh/rke_rsa.pub
kubernetes_version: "v1.20.11-rancher1-2"

ingress:
  provider: nginx
  network_mode: hostPort
  http_port: 8888
  https_port: 9999
  node_selector:
    app: ingress

private_registries:
     - url: registry.DOAMIN_NAME
       user: USER_NAME
       password: USER_PASSWORD 
       is_default: false

1. 192.168.1.109: controlplane, etcd, worker (master+worker)
2. 192.168.1.105: worker, ingress (worker)

Ingress will run on “192.168.1.105”.

Get the latest RKE binary.

RKE Binary

Installation note

1. To start building the cluster

Make sure you have your own cluster.yml file in the same folder. RKE runs on almost any Linux OS with Docker installed.

Reference: general-linux-requirements

$ ./rke up
INFO[0000] Building Kubernetes cluster
...
INFO[0101] Finished building Kubernetes cluster successfully

1. After RKE init our new kubernetes clsuter. kubectl will use this secret to connect our cluster.

   $ cp kube_config_cluster.yml ~/.kube/config
   

   By default, kubectl checks ~/.kube/config for a kubeconfig file, but you can use any directory you want using the –kubeconfig flag. For example:

   kubectl --kubeconfig /custom/path/kube.config get pods
   

2. Let’s check nodes status.

   ➜  $ kubectl get node
   NAME            STATUS   ROLES                      AGE   VERSION
   192.168.1.105   Ready    worker                     36d   v1.20.11
   192.168.1.109   Ready    controlplane,etcd,worker   36d   v1.20.11
   

Now you have a k8s cluster!!