DigitalOcean Terraform MicroK8s

This currently works for 1.19+ channel.

Use only with terraform v0.14

Bootstrap a Highly Available MicroK8s cluster in DigitalOcean with Terraform.

For example to bootstrap a 7 node cluster.

module "microk8s" {
  source = "git::https://github.com/balchua/do-microk8s?ref=master"
  node_count                   = "7"
  os_image                     = "ubuntu-20-04-x64"
  node_size                    = "s-4vcpu-8gb"
  node_disksize                = "2"
  region                       = "sgp1"
  dns_zone                     = "geeks.sg"
  microk8s_channel             = "latest/edge"
  cluster_token                = "PoiuyTrewQasdfghjklMnbvcxz123409"
  cluster_token_ttl_seconds    = 3600
  digitalocean_ssh_fingerprint = var.digitalocean_ssh_fingerprint
  digitalocean_private_key     = var.digitalocean_private_key
  digitalocean_token           = var.digitalocean_token
  digitalocean_pub_key         = var.digitalocean_pub_key
}

The cluster_token must be 32 alphanumeric characters long.

DigitalOcean TF environment variables

You must have these environment variables present.

TF_VAR_digitalocean_token=<your DO access token>
TF_VAR_digitalocean_ssh_fingerprint=<Your private key fingerprint>
TF_VAR_digitalocean_private_key=<location of your private key>
TF_VAR_digitalocean_pub_key=<location of your public key>

Creating the cluster

Simply run the terraform plan and then terraform apply

Once terraform completes, you should be able to see the cluster.

Login to one of the node using ssh root@node, then issue the command below.

root@microk8s-node-cetacean-0:~# microk8s kubectl get no
NAME                       STATUS   ROLES    AGE     VERSION
microk8s-node-cetacean-0   Ready    <none>   6m36s   v1.20.4-38+85035ca77e3c6e
microk8s-node-cetacean-2   Ready    <none>   4m33s   v1.20.4-38+85035ca77e3c6e
microk8s-node-cetacean-6   Ready    <none>   4m47s   v1.20.4-38+85035ca77e3c6e
microk8s-node-cetacean-5   Ready    <none>   4m21s   v1.20.4-38+85035ca77e3c6e
microk8s-node-cetacean-4   Ready    <none>   4m15s   v1.20.4-38+85035ca77e3c6e
microk8s-node-cetacean-3   Ready    <none>   4m12s   v1.20.4-38+85035ca77e3c6e
microk8s-node-cetacean-1   Ready    <none>   4m6s    v1.20.4-38+85035ca77e3c6e

Downloading Kube config file

The module automatically downloads the kubeconfig file to your local machine in /tmp/client.config In order to access the Kubernetes cluster from your local machine, simple do export KUBECONFIG=/tmp/client.config

This will connect using the load balancer fronting the api servers. The dns entry will be microk8s-cluster.<domain name>

Example: microk8s-cluster.geeks.sg

MicroK8s High Availability

It requires node counts to be greater than or equal to 3 to form a majority. Each node can be a control plane, hence there is really no concept of control plane.

Check documentation on MicroK8s Discuss HA

Digitalocean attached volume

This terraform also creates and attach a volume to each droplet. This will let you setup Rook + Ceph storage. This way you can freely create volumes that you can share to your pods.

Persistent Volumes

The following sections describes how to install Rook/Ceph, Longhorn and OpenEBS with MicroK8s

Using Rook / Ceph

Some instructions on how to use Rook

Using Longhorn storage

Some instructions on how to use Longhorn

Using OpenEBS

Instructions on how to install OpenEBS