⚠️ Deprecation notice

This preview integration of IoT Edge 1.x and Kubernetes will not be made generally available, and is no longer supported. The recommended way to run IoT Edge 1.x on Kubernetes is noted in the product's official docs

This example demonstrates how to expose an in-cluster Kubernetes Service from an IoT Edge module. It requires a Kubernetes cluster with Helm initialized and kubectl installed as noted in the prerequisites. You'll also be using VS Code with Azure IoT tools to work with the edge workload (deployment) manifest.

Setup steps

  1. As needed, follow the steps to register an IoT Edge device. Take note of the device connection string.

  2. Set up VS Code and tools, associate with IoT Hub from the previous step.

  3. Follow steps, or a subset as needed, to install edge deployment into the cluster.

    For simplicity, this tutorial doesn't specify a persistent store for iotedged during install. However, for any serious/PoC deployment, follow the best practice example shown in the iotedged failure resilience tutorial.

    
# Create K8s namespace
kubectl create ns internal-service

# Install IoT Edge CRD, if not already installed
helm install --repo https://edgek8s.blob.core.windows.net/staging edge-crd edge-kubernetes-crd

# Store the device connection string in a variable (enclose in single quotes)
export connStr='replace-with-device-connection-string-from-step-1'


# Install the edge workload into the cluster namespace
helm install --repo https://edgek8s.blob.core.windows.net/staging internal-service-example edge-kubernetes \
  --namespace internal-service \
  --set "provisioning.deviceConnectionString=$connStr"

  4. In the Visual Studio Code command palette (View menu -> Command Palette...), search for and select Azure IoT Edge: New IoT Edge Solution. Follow the prompts and use the following values to create your solution:

    FieldValue
    Select folderChoose the location on your development machine for VS Code to create the solution files.
    Provide a solution nameEnter a descriptive name for your solution or accept the default EdgeSolution.
    Select module templateChoose Empty solution.

    You'll update deployment.template.json (see navigation pane on the left) to add a sample module that exposes an in-cluster endpoint as a Kubernetes Service.

  5. Add a sample aspnetapp module under edgeAgent's properties.desired section as shown below.

    The PortBindings section of module's createOptions is translated to a Kubernetes Service of type ClusterIP by default. This type of service is not accessible outside the cluster directly.

    You can change HostPort in the module's createOptions to configure the port exposed by the service.

    {
  "$schema-template": "2.0.0",
  "modulesContent": {
    "$edgeAgent": {
      "properties.desired": {
        "schemaVersion": "1.0",
        "runtime": {
          "type": "docker",
          "settings": {
            "minDockerVersion": "v1.25",
            "loggingOptions": "",
            "registryCredentials": {}
          }
        },
        "systemModules": {
          "edgeAgent": {
            "type": "docker",
            "settings": {
              "image": "mcr.microsoft.com/azureiotedge-agent:1.0",
              "createOptions": {}
            }
          },
          "edgeHub": {
            "type": "docker",
            "status": "running",
            "restartPolicy": "always",
            "settings": {
              "image": "mcr.microsoft.com/azureiotedge-hub:1.0",
              "createOptions": {
                "HostConfig": {
                  "PortBindings": {
                    "5671/tcp": [
                      {
                        "HostPort": "5671"
                      }
                    ],
                    "8883/tcp": [
                      {
                        "HostPort": "8883"
                      }
                    ],
                    "443/tcp": [
                      {
                        "HostPort": "443"
                      }
                    ]
                  }
                }
              }
            }
          }
        },
        "modules": {
+         "aspnetapp": {
+           "settings": {
+             "image": "mcr.microsoft.com/dotnet/core/samples:aspnetapp",
+             "createOptions": {
+               "HostConfig": {
+                 "PortBindings": {
+                   "80/tcp": [
+                     {
+                       "HostPort": "8082"
+                     }
+                   ]
+                 }
+               }
+             }
+           },
+           "type": "docker",
+           "version": "1.0",
+           "status": "running",
+           "restartPolicy": "always"
+         }
        }
      }
    },
    "$edgeHub": {
      "properties.desired": {
        "schemaVersion": "1.0",
        "routes": {},
        "storeAndForwardConfiguration": {
          "timeToLiveSecs": 7200
        }
      }
    }
  }
}

  6. Generate the workload deployment config by right-clicking the deployment.template.json in the left navigation pane and selecting Generate IoT Edge Deployment Manifest. This will generate the minified deployment.amd64.json under the config directory.

  7. Update the configuration for the device by right-clicking deployment.amd64.json and selecting Create Deployment for Single Device. In the displayed list, choose the device created in step 1 to complete the operation.

  8. In a few seconds, you'll see a new pods and services instantiated as defined in the deployment manifest. Check the Services in the namespace to confirm that there's an entry for aspnetapp.

    kubectl get services -n internal-service

Cleanup


# Cleanup
helm del internal-service-example -n internal-service && \
kubectl delete ns internal-service

...will remove all the Kubernetes resources deployed as part of the edge deployment in this example (IoT Edge CRD will not be deleted).