DOKS_challenge

Hi, My name is Magnus, also known as nigma1337, and this is my explaination of the Digitalocean kubernetes challenge, upgrade inside a vcluster.

Step 0.5

First off, we need to create a cluster. Personally, I made a terraform configuration to create a cluster on digitalocean, just as a small added challenge, just add your API key (which can be gotten via the DO website, under the API menu) to terraform.tfvars and do terraform apply. You can also just create the cluster via the digitalocean website. I'm gonna go with DOKS version 1.19.15-do.0, and as i'm planning to upgrade it to version 1.21.5-do.0, because I need to make sure my workflow is compatible with Kubernetes version 1.21.5

Also made sure to grab the kubeconfig file, via doctl kubernetes cluster kubeconfig show -t <API-KEY-HERE> terraform-do-cluster >> ~/.kube/config, which will also set our current context to the new cluster

I didn't use doctl kubernetes cluster kubeconfig save, as that didn't work for me, throwing an error about the cluster not being found

Step 1

Now, let's get to the real part. Install the vcluster CLI via

curl -s -L "https://github.com/loft-sh/vcluster/releases/latest" | sed -nE 's!.*"([^"]*vcluster-linux-amd64)".*!https://github.com\1!p' | xargs -n 1 curl -L -o vcluster && chmod +x vcluster;
sudo mv vcluster /usr/local/bin;

(commands taken from https://www.vcluster.com/docs/getting-started/setup)

Step 2

Time to create the vcluster.

The command we'll run looks like this: vcluster create <name> -n <namespace> --k3s-image <k3s image name>

So after filling out the blanks, we'll end up with this, as we want k3s version 1.21.5: vcluster create testcluster -n virtual-cluster --k3s-image rancher/k3s:v1.21.5-k3s2

Then, run kubectl get pods -n virtual-cluster to check the status of our virtual cluster, it should look something like this

NAME                                                   READY   STATUS    RESTARTS   AGE
coredns-7448499f4d-d5vs6-x-kube-system-x-testcluster   1/1     Running   0          67s
testcluster-0                                          2/2     Running   0          99s

Step 3

Let's connect to the cluster!

The output of our create commands tells us to use vcluster connect testcluster --namespace virtual-cluster to access the cluster.

This writes a kubeconfig.yaml file to your current directory, which allows kubectl access to the cluster, and forwards local port 8443 to port 8443 on the cluster.

Cleanup

To cleanup, remove the cluster via terraform destroy or via the digitalocean website. Keep in mind, you also have to manually delete the volume vcluster created.

Nigma1337 / DOKS_challenge