This repository contains two methods of getting a working Kubernetes cluster on Oracle Cloud using their Always Free resources.
- Using their managed Kubernetes service: Oracle Container Engine for Kubernetes (OKE)
- Using k3s with a highly available (embedded etcd) control plane
In both cases the nodes will be of the Ampere ARM64 variety, because you get 4 cores and 24GB RAM worth of nodes this way. You only get a couple of 1 core 1GB RAM nodes using x86 processors.
I make no promises to keep this repo up to date, but it should serve as a good example of how to get started with Kubernetes on Oracle Cloud Infrastructure.
You will need an account on Oracle Cloud. You'll be given some credits (£250 in the UK) initially but you shouldn't see them being used by anything in this repository; everything should be covered by the Always Free resources and OKE is free anyway.
When your account is activated you'll need to install and configure the OCI CLI get some details to populate the terraform.tfvars file, which are used to authentiate to your account. The information of how to get these details are in Oracle's Documentation.
At the end of the trial period you will need to convert your account to a paid account rather than leaving it as a free tier account. This is because whilst OKE is free, it is not supported (yet) on a free account. The documentation also says that the Ampere instances will be terminated and need reprovisioning, although I didn't encounter this.
I recommend you setup Budgets on your account to ensure you get alerted if you are running up a bill. Unfortunately I am currently being billed £0.05 a day for the boot volume of one of my nodes, but I can live with that. This might be down to the many things I've tried on my account and I'd be interested to hear if others also get the same issue.
With the account created and terraform.tfvars file populated, creating your cluster should then be as simple as opening a terminal in the relevant directory and running terraform init followed by terraform apply.
If you want to use Remote State for your Terraform state file you will need to perform additional configuration. I am storing mine in OCI Object Storage using a Pre Authenticated Request URL, using the method in this medium post. You could also use Oracle Cloud's Resource Manager managed Terraform service.
The Terraform creates a generated directory containing your kubeconfig file. You can either use this where it is by running export KUBECONFIG=/path/to/generated/kubeconfig or copy it to the default path used by kubectl at ~/.kube/config.
At this point you will need to make sure you have the OCI CLI installed, as that is used for authentication to your new cluster.
You should now be able to run commands like kubectl get no and see you have a cluster up and running with two nodes.
You will need to use Oracle managed bastion service (already configured by the terraform) to SSH into one of the control plane nodes. The username will be opc. You will find a kubeconfig file in /etc/rancher/k3s/k3s.yaml but for it to work locally you will need to change the IP address to that of your Load Balancer using https on port 6443.
You will see there are 4 nodes; 3 control plane and 1 worker. All with 1 CPU core and 6 GB RAM.