Using Terraform to Deploy KinD Kubernetes Clusters

In this post we will use Terraform to deploy a 2 node KinD Kubernetes cluster.

If you are looking for related content, you can look under my kind tags for related tutorials.

Assumptions

I will make the assumption that you already have the following tools installed:

KinD runs kubernetes nodes as docker containers, which is why we need docker to be installed if you are following this tutorial.

Write Terraform Code

We will create the directory where we will be defining our terraform code:

mkdir workspace

Then change to our directory:

cd workspace

Then we need to find a kind terraform provider, there are a couple online, but I went with tehcyx/kind.

Then we will define our providers.tf:

providers.tf

terraform {
  required_providers {
    kind = {
      source = "tehcyx/kind"
      version = "0.4.0"
    }
  }
}

provider "kind" {}

Then we can define our kind_cluster resource in our main.tf, where we want to define the following:

Write the kubeconfig file to /tmp/config
Define the cluster name
Define the kubernetes version (versions: kind/releases )
Define the node roles
Define the port mappings from the host to the container

For more configuration see the provider documentation.

main.tf

resource "kind_cluster" "default" {
    name            = "test-cluster"
    node_image      = "kindest/node:v1.27.1"
    kubeconfig_path = pathexpand("/tmp/config")
    wait_for_ready  = true

    kind_config {
      kind        = "Cluster"
      api_version = "kind.x-k8s.io/v1alpha4"

      node {
          role = "control-plane"
          extra_port_mappings {
              container_port = 80
              host_port      = 80
          }
      }

      node {
          role = "worker"
      }
  }
}

If you are using terraform to consume outputs such as the cluster ca certificate, client certificate etc, from kubernetes like the helm provider you can do that, but I will just reference them as outputs as demonstration in outputs.tf.

outputs.tf

output "kubeconfig" {
  value = kind_cluster.default.kubeconfig
}

output "endpoint" {
  value = kind_cluster.default.endpoint
}

output "client_certificate" {
  value = kind_cluster.default.client_certificate
}

output "client_key" {
  value = kind_cluster.default.client_key
}

output "cluster_ca_certificate" {
  value = kind_cluster.default.cluster_ca_certificate
}

Initialize Terraform

Now that we have defined our terraform configuration, we can run a terraform init which will download the providers:

terraform init

We can then run terraform plan which will show us what terraform will want to deploy:

terraform plan

Which in my case shows the following:

Terraform will perform the following actions:

  # kind_cluster.default will be created
  + resource "kind_cluster" "default" {
      + client_certificate     = (known after apply)
      + client_key             = (known after apply)
      + cluster_ca_certificate = (known after apply)
      + completed              = (known after apply)
      + endpoint               = (known after apply)
      + id                     = (known after apply)
      + kubeconfig             = (known after apply)
      + kubeconfig_path        = "/tmp/config"
      + name                   = "test-cluster"
      + node_image             = "kindest/node:v1.27.1"
      + wait_for_ready         = true

      + kind_config {
          + api_version = "kind.x-k8s.io/v1alpha4"
          + kind        = "Cluster"

          + node {
              + role                   = "control-plane"

              + extra_port_mappings {
                  + container_port = 80
                  + host_port      = 80
                }
            }
          + node {
              + role = "worker"
            }
        }
    }

Plan: 1 to add, 0 to change, 0 to destroy.

If you are happy with the proposed changes, you can run a terraform apply:

terraform apply -auto-approve

This took about 2 minutes for me to have a cluster deployed. This will depend on your internet speed and if the kind container image has been downloaded before.

Interact with your Kubernetes Cluster

First we need to set our KUBECONFIG environment variable to point to the config file that terraform created:

export KUBECONFIG=/tmp/config

Now we can use kubectl to view our nodes:

kubectl get nodes -o wide

This should output something like the following:

test-cluster-control-plane   Ready    control-plane   3m46s   v1.27.1   172.24.0.3    <none>        Debian GNU/Linux 11 (bullseye)   5.15.0-101-generic   containerd://1.6.21
test-cluster-worker          Ready    <none>          3m22s   v1.27.1   172.24.0.2    <none>        Debian GNU/Linux 11 (bullseye)   5.15.0-101-generic   containerd://1.6.21

We can test our cluster by creating a nginx deployment:

kubectl create deployment demo --image=nginx --port=80 --namespace=default

We can then view our pods:

kubectl get pods -n default -o wide

Which will show us this output:

NAME                   READY   STATUS    RESTARTS   AGE   IP           NODE                   NOMINATED NODE   READINESS GATES
demo-59989484f-rtbdk   1/1     Running   0          67s   10.244.1.2   test-cluster-worker    <none>           <none>

Cleanup

We can tear down the cluster by running terraform destroy:

terraform destroy -auto-approve

Thank You

The code for this demonstration can be found in my quick-starts repository.

Thanks for reading, if you like my content, feel free to check out my website, and subscrube to my newsletter or follow me at @ruanbekker on Twitter.

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