☁️ Oracle Cloud k8s (Free)

This repo utilizes the always free tier of the oracle cloud to provision a kubernetes cluster.

⚠️ This project uses arm instances, no x86 architecture. This means, that you can use only ARM images in your cluster (most bakers create also ARM images)

At oracle cloud the Kubernetes controlplane (oke) is free to use, you just pay for the workers, if you surpass the always free tier (which we don't).

You get 4 oCpus and 24GB memory which are split into two worker-instances (VM.Standard.A1.Flex -> arm), allowing good resource utilization. The boot partions are 100Gb each, allowing us to use around 60GB as in cluster storage.

The initial infra setup is inspired by this great tutorial: https://arnoldgalovics.com/free-kubernetes-oracle-cloud/

and this repo (big thanks @Ulli) https://github.com/nce/oci-free-cloud-k8s

Preconditions

The setup is based on Terraform, so you need experience with Terraform

Presteps

1. Create account at OCI - https://www.oracle.com/cloud/
2. Install oci-cli
3. Create oci-cli-Config. User and tenancy IDs from the web console. I chose eu-frankfurt-1 as region. Set a name for the

oci setup config 

4. Add the generated public key to your profile. Web console->My Profile->API Keys->Add API key

⌨️ Create the k8s-cluster (OKE)

This part is managed by infra

Create a terraform.tfvars in the infra folder

compartment_id = "ocid1.tenancy.oc1..*"
ssh_public_key = "your SSH key"

Than put terraform to work

cd infra
terraform init
terraform apply

If everything goes well, you should be the proud owner of a k8s cluster in OCI.

kubeconfig

With the following command we get the kubeconfig for terraform/direct access:

# in the infra folder
oci ce cluster create-kubeconfig --cluster-id $(terraform output --raw k8s_cluster_id) --file ~/.kube/configs/oci.kubeconfig --region eu-frankfurt-1 --token-version 2.0.0 --kube-endpoint PUBLIC_ENDPOINT

Test: check your k8s nodes.

1. Install kubectl
2. Run

kubectl --kubeconfig ~/.kube/configs/oci.kubeconfig get nodes

🔧 Additional tooling (optional)

• Nginx-Ingress (with the oracle Network Load Balancer, because that's free as well)
• Certmanager with letsencrypt
• Longhorn (Storage)

The tools are managed by terraform in config

Create a terraform.tfvars in the infra folder

compartment_id   = "ocid1.tenancy.oc1..*"
k8s_config_path = "~/.kube/configs/oci.kubeconfig"
letsencrypt_email = "myemail"

Than put terraform again to work

cd config
terraform init
terraform apply

Test your ingress

The whoami-ingress folder contains a test-deployment for your new k8s cluster (terraform + helm). Replace example.com bellow with your domain.

1. Get the external IP of the LB

kubectl get services -n ingress-nginx \
ingress-nginx-controller \
--output jsonpath='{.status.loadBalancer.ingress[0].ip}'

2. Create DNS record type A in your example.com DNS zone like this: *.oci.example.com with value == the external IP from previous step and check until your record is being published. Something like this should be helpful.

dig foobar.oci.example.com

3. Create a terraform.tfvars in the folder

host = "whoami.oci.example.com"

4. Than put terraform again to work

cd examples/whoami-ingress
terraform init
terraform apply

5. At the end you should be able to reach your new deployment via browser or in terminal (curl => no cache issues):

curl https://whoami.oci.example.com

Optimisations & Ideas

• Put your terraform state file to a remote backend (GitLab, GitHub, S3 ... ). There are many backends available.
• Use eternal-dns