Introduction to Kubernetes

This repository contains the source code for creating a local Kubernetes cluster setup using either K3d or Rancher Kubernetes Engine (RKE). It also contains a set of manifest files to deploy a basic application to your local K8s cluster.

Slide Deck

The slide deck for the Introduction to Kubernetes course can be found in the slide-deck folder.

Create Local Kubernetes Cluster with K3d

k3d is a lightweight wrapper to run k3s (Rancher Lab’s minimal Kubernetes distribution) in docker.

Requirements/Prerequisites

• Docker
• Install K3d

Provision Cluster with K3d

The first step is to ensure that the docker engine is running on your machine. Once you've verified that, you can proceed to create a cluster with the following command:

k3d cluster create example-cluster --servers 3 --agents 2

Delete Cluster with K3d

You can delete a cluster with the following command:

k3d cluster delete example-cluster

Create Local Kubernetes Cluster with RKE

RKE is a CNCF-certified Kubernetes distribution that runs entirely within Docker containers.

Requirements/Prerequisites

• Rancher Kubernetes Engine (RKE)
• Virtual Box
• Vagrant

Create Virtual Machines (VMs)

To spin up the virtual machines, run the following command at the root level of the project directory:

vagrant up

Once the VMs are up and running, you can check their status with vagrant status or by connecting to anyone of them using vagrant ssh [hostname]. Once you've confirmed that all machines are running with no issues, copy over the generated SSH keys from your workstation/host to each guest machine with the following commands:

ssh-copy-id root@[relevant ip address]

When prompted, enter the root user password configured in the bootstrap node script.

Provision/Create Kubernetes Cluster with RKE

To provision the cluster on the VMs, run the rke config command. You will be presented with a series of questions to which the answers will be used to declare the cluster config in a generated cluster.yml file upon completion. Alternatively, you can create the cluster.yml file and populate it with your desired configuration. Once you have the cluster.yml file, run the following command:

rke up

When the cluster has been provisioned, the following files will be generated in the root directory:

• cluster.rkestate - the cluster state file
• kube_config_cluster.yml - kube config file

To add the cluster to your context, copy the kube config file:

cp kube_config_cluster.yml ~/.kube/config

If you do not have a ./kube directory on your machine you will have to create one.

The last step will be to check that you can connect to your cluster:

kubectl cluster-info

or

kubectl config current-context

Manifests

The Kubernetes resources can be found inside the manifests folder.