Use wasmCloud on Azure Kubernetes Service (AKS)

WebAssembly components are a new way to build and deploy applications. They're designed to be a portable compilation target for programming languages and can run in various environments. WebAssembly components are sandboxed by design and expose their functionality using defined interfaces. Components differ from containers in that they single binaries that are much smaller and faster to start. Find the full description of the model and what a component in the specification.

wasmCloud is a Cloud Native Computing Foundation (CNCF) project designed to fast-track the development, deployment, and orchestration of WebAssembly components. This document details instructions on how to deploy wasmCloud on an Azure Kubernetes Service (AKS) cluster.

Before you begin

Prerequisites

  • You can't use the Azure portal to deploy wasmCloud to an AKS cluster.

Deploy wasmCloud

To deploy wasmCloud on an AKS cluster, you need to install the all in one Helm chart into your cluster. This installs the following services into a single namespace:

  • NATS: NATS provides the backbone for all communication between components in wasmCloud.
  • wadm: the wasmCloud Application Manager, otherwise known as wadm is the orchestrator for managing applications running on top of wasmCloud.
  • the wasmCloud Operator: the wasmCloud Operator is a Kubernetes operator that manages the lifecycle of wasmCloud hosts.

We recommend deploying wasmCloud into a dedicated Kubernetes namespace.

  1. Create a namespace for wasmCloud using kubectl:

    kubectl create namespace wasmcloud

  2. Install NATS and wadm into the wasmCloud namespace using the helm upgrade command:

    # By default, the chart installs NATS, Wadm, and wasmCloud Operator subcharts
 helm upgrade --install \
      wasmcloud-platform \
      --values https://raw.githubusercontent.com/wasmCloud/wasmcloud/main/charts/wasmcloud-platform/values.yaml \
      oci://ghcr.io/wasmcloud/charts/wasmcloud-platform:0.1.2 \
      --dependency-update

    The output from this command should look similar to the following:

    NAME: wasmcloud-platform
LAST DEPLOYED: Thu Nov  7 14:58:54 2024
NAMESPACE: default
STATUS: deployed
REVISION: 1
NOTES:

  3. Wait for all of the pods to start using kubectl:

    kubectl rollout status deploy,sts -l app.kubernetes.io/name=nats
kubectl wait --for=condition=available --timeout=600s deploy -l app.kubernetes.io/name=wadm
kubectl wait --for=condition=available --timeout=600s deploy -l app.kubernetes.io/name=wasmcloud-operator

  4. Start a wasmCloud host using a CRD and kubectl:

    cat << EOF | kubectl apply -f -
apiVersion: k8s.wasmcloud.dev/v1alpha1
kind: WasmCloudHostConfig
metadata:
  name: wasmcloud-host
spec:
  lattice: default
  version: "1.4.1"
EOF

  5. Verify that the wasmCloud host is running:

    kubectl get pod -l app.kubernetes.io/instance=wasmcloud-host

    Your output should look similar to the following:

    NAME                             READY   STATUS    RESTARTS   AGE
wasmcloud-host-f9d67b8cf-lvsq6   2/2     Running   0          84s

  6. Verify that you can connect to the wasmCloud host using wash:

    In a separate shell use run the following command to port forward to one of the running NATS pods:

    kubectl port-forward nats-0 4222

    This command forwards all traffic on port 4222 locally to the NATS pod running in your cluster. You must have this port forwarded in order to connect to wasmCloud using wash.

    In your original shell, run the following command with wash to verify that your wasmCloud host is running:

    wash get hosts

    Your output should look similar to the following:

      Host ID                                                      Friendly name           Uptime (seconds)
  ND2G4FRXLBCV3YL52OD4NRSS66Z5YOR3JOSL3Q7T5I6ZJM4EII3Y73CZ     frosty-resonance-6227   312

Deploy a wasmCloud application

Now that wasmCloud is running on your AKS cluster, you can deploy a wasmCloud application. A wasmCloud application is a collection of WebAssembly components that are orchestrated by the wasmCloud Application Manager (wadm).

  1. Create a wasmCloud application manifest file. This file describes components that comprise your application. Save the following yaml file as hello-world.yaml.

    apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
  name: hello-world
  annotations:
    description: 'HTTP hello world demo in Rust, using the WebAssembly Component Model and WebAssembly Interfaces Types (WIT)'
spec:
  components:
    - name: http-component
      type: component
      properties:
        image: ghcr.io/wasmcloud/components/http-hello-world-rust:0.1.0
      traits:
        # Govern the spread/scheduling of the component
        - type: spreadscaler
          properties:
            instances: 1

    # Add a capability provider that enables HTTP access
    - name: httpserver
      type: capability
      properties:
        image: ghcr.io/wasmcloud/http-server:0.23.2
      traits:
        # Establish a unidirectional link from this http server provider (the "source")
        # to the `http-component` component (the "target") so the component can handle incoming HTTP requests,
        #
        # The source (this provider) is configured such that the HTTP server listens on 0.0.0.0:8080
        - type: link
          properties:
            target: http-component
            namespace: wasi
            package: http
            interfaces: [incoming-handler]
            source_config:
              - name: default-http
                properties:
                  address: 0.0.0.0:8080

  2. Deploy the wasmCloud application using wash:

    wash app deploy hello-world.yaml

    Your output should look similar to the following:

    Deployed application "hello-world", version "01JC44TVDBC2V6MJ1NJTKNNX1J"

  3. Verify that the application is running using wash:

    wash app status hello-world

    Your output should look similar to the following:

    Name                                         Kind           Status
http_component                               SpreadScaler   Deployed
httpserver -(wasi:http)-> http_component     LinkScaler     Deployed
httpserver                                   SpreadScaler   Deployed

    Repeat this command if necessary until all components are in the Deployed state.

  4. Invoke the http component using curl and kubectl port-forward:

    In a separate shell, run the following command to port forward to the hello-world application

    kubectl port-forward port-forward deployment/wasmcloud-host 8080

    This command forwards all traffic on port 8080 locally to the wasmCloud host running in your cluster. You must have this port forwarded in order to connect to wasmCloud using curl.

    In your original shell, run the following command to invoke the http component:

    curl http://localhost:8080

    Your output should look similar to the following:

    Hello from Rust!

  5. Clean up the installed resources

    To clean up the resources you created, run the following commands:

    kubectl delete namespace wasmcloud

    This command removes the wasmCloud components from your AKS cluster.

Next steps

You can continue to learn by following the wasmCloud Quickstart Guide, which walks you though creating a WebAssembly component from scratch, using different wasmCloud capabilities and scaling your application.

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