Building an Acorn Development Environment with Multipass and K3s

Acorn can be installed in environments such as Docker Desktop, Minikube, or MicroK8s running on a developer workstation. There are instances where you may want to emulate a multi-node cluster that mimics the production environment to deploy and test Acorn apps.

This tutorial walks you through the steps involved in creating a multi-node Kubernetes cluster based on Multipass and K3s that expose the services through MetalLB and Nginx Ingress.

You can configure the cluster on macOS based on the Intel chip or Apple Silicon. It works identically in both architectures.

Step 1 – Installing Multipass and Launching Ubuntu VMs

Multipass is a tool from Canonical to launch Ubuntu virtual machines in Windows, macOS, and Linux OS. It abstracts the steps involved in downloading the images, configuring the VM, and launching it.

Multipass uses Hyper-V on Windows, QEMU and HyperKit on macOS, and LXD on Linux for minimal overhead and the fastest possible start time.

Assuming you have Brew installed on your Mac, run the below command to install Multipass:

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Once Multipass is installed, it’s time to launch three Ubuntu 20.04 VMs with 4 CPUs, 4GB of RAM, and 20G of storage.

multipass launch 20.04 --name node-2 --cpus 4 --disk 20G --mem 4G
multipass launch 20.04 --name node-3 --cpus 4 --disk 20G --mem 4G

Let’s verify that the VMs are ready.

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Step 2 – Installing and Configuring K3s Cluster

With the VMs already launched, let’s install K3s. Node-1 will act as the server, while the remaining two runs the agent.

To SSH into the first node, run the below command:

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Let’s install the K3s server in this node. Since we plan to use Nginx as Ingress and MetalLB as the load balancer, we will disable Traefik and ServiceLB.

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SSH into the remaining two nodes and run the following command:

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The IP address 192.168.64.7 corresponds to node-1, that’s running the server.

On node-1, run the following command to verify that the K3s cluster is up and running:

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While you are still within the SSH session on node-1, copy the contents K3s configuration file to access the cluster from your workstation through kubectl.

Create the kubeconfig file on your Mac by replacing 127.0.0.1 with the IP address of node-1.

Set the KUBECONFIG environment variable to the file you updated. On my machine, I copied k3s.yaml to k3s-kubeconfig.

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Verify that you can access the K3s cluster from Mac.

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Our ingress is available at 192.168.64.200 , which is the first IP address in the pool.

With the Kubernetes environment and the prerequisites in place, let’s go ahead and install Acorn.

Step 3 – Installing Acorn and Running Apps

Assuming you have the latest version of Acorn CLI, run the below command to install it.

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Let’s run a simple web server based on the below Acornfile to check the installation:

 "default": {
  image: "nginx"
  ports: publish: "80/http"
  files: {
   // Simple index.html file
   "/usr/share/nginx/html/index.html": "<h1>My First Acorn!</h1>"
  }
 }
}

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Wait for the service to get associated with the ingress.

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Hit the endpoint with curl to test the service.

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We have successfully configured a multi-node development and test environment to deploy Acorn apps. To learn more about using acorn, visit our getting started guide, or join us for an upcoming meetup or training.

Janakiram is a practicing architect, analyst, and advisor focusing on emerging infrastructure technologies. He provides strategic advisory to hyperscalers, technology platform companies, startups, ISVs, and enterprises. As a practitioner working with a diverse Enterprise customer base across cloud native, machine learning, IoT, and edge domains, Janakiram gains insight into the enterprise challenges, pitfalls, and opportunities involved in emerging technology adoption. Janakiram is an Amazon, Microsoft, and Google certified cloud architect, as well as a CNCF Ambassador and Microsoft Regional Director. He is an active contributor at Gigaom Research, Forbes, The New Stack, and InfoWorld.