Integrating With Rancher Desktop

Rancher Desktop is an open-source application that provides all the essentials to work with containers and Kubernetes on your desktop.

Prerequisites

The prerequisites for this tutorial are Rancher Desktop and assets listed in the SpinKube quickstart. Let’s dive in.

Rancher Desktop

First, install the latest version of Rancher Desktop.

Rancher Desktop Preferences

Check the “Container Engine” section of your “Preferences” to ensure that containerd is your runtime and that “Wasm” is enabled. As shown below.

Also, select rancher-desktop from the Kubernetes Contexts configuration in your toolbar.

SpinKube

The following commands are from the SpinKube Quickstart guide. Please refer to the quickstart if you have any queries.

The following commands install all of the necessary items that can be found in the quickstart:

kubectl apply -f https://github.com/cert-manager/cert-manager/releases/download/v1.14.3/cert-manager.yaml
kubectl apply -f https://github.com/spinkube/spin-operator/releases/download/v0.1.0/spin-operator.crds.yaml
kubectl apply -f https://github.com/spinkube/spin-operator/releases/download/v0.1.0/spin-operator.runtime-class.yaml
kubectl apply -f https://github.com/spinkube/spin-operator/releases/download/v0.1.0/spin-operator.shim-executor.yaml

helm install spin-operator \
  --namespace spin-operator \
  --create-namespace \
  --version 0.1.0 \
  --wait \
  oci://ghcr.io/spinkube/charts/spin-operator
helm repo add kwasm http://kwasm.sh/kwasm-operator/

helm install \
  kwasm-operator kwasm/kwasm-operator \
  --namespace kwasm \
  --create-namespace \
  --set kwasmOperator.installerImage=ghcr.io/spinkube/containerd-shim-spin/node-installer:v0.14.1

kubectl annotate node --all kwasm.sh/kwasm-node=true

Creating Our Spin Application

Next, we create a new Spin app using the Javascript template:

spin new -t http-js hello-k3s --accept-defaults
cd hello-k3s
npm install

We then edit the Javascript source file (the src/index.js file) to match the following:

export async function handleRequest(request) {
    return {
        status: 200,
        headers: {"content-type": "text/plain"},
        body: "Hello from Rancher Desktop" // <-- This changed
    }
}

All that’s left to do is build the app:

spin build

Deploying Our Spin App to Rancher Desktop with SpinKube

We publish our application using the spin registry command:

spin registry push ttl.sh/hello-k3s:0.1.0

Once published, we can read the configuration of our published application using the spin kube scaffold command:

spin kube scaffold --from ttl.sh/hello-k3s:0.1.0

The above command will return something similar to the following YAML:

apiVersion: core.spinoperator.dev/v1alpha1
kind: SpinApp
metadata:
  name: hello-k3s
spec:
  image: "ttl.sh/hello-k3s:0.1.0"
  executor: containerd-shim-spin
  replicas: 2

Now, we can deploy the app into our cluster:

spin kube deploy --from ttl.sh/hello-k3s:0.1.0

If we click on the Rancher Desktop’s “Cluster Dashboard”, we can see hello-k3s:0.1.0 running inside the “Workloads” dropdown section:

To access our app outside of the cluster, we can forward the port so that we access the application from our host machine:

kubectl port-forward svc/hello-k3s 8083:80

To test locally, we can make a request as follows:

curl localhost:8083

The above curl command will return the following:

Hello from Rancher Desktop