Schedule on specific nodes - Deploy Azure IoT Edge on Kubernetes (preview)

⚠️ 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 assign modules to run on specific nodes. 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

As needed, follow the steps to register an IoT Edge device. Take note of the device connection string.
Set up VS Code and tools, associate with IoT Hub from the previous step.

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 nodeselector

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

Deploy the edge workload into the previously created K8s namespace.


helm install --repo https://edgek8s.blob.core.windows.net/staging node-selector-example edge-kubernetes \
  --namespace nodeselector \
  --set "provisioning.deviceConnectionString=$connStr"

List the nodes in your cluster.
```
kubectl get nodes
```

Pick one of the nodes and add a label to it like so:


kubectl label nodes <node-name> edgehub=true

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:

Field	Value
Select folder	Choose the location on your development machine for VS Code to create the solution files.
Provide a solution name	Enter a descriptive name for your solution or accept the default EdgeSolution.
Select module template	Choose Empty solution.

Make updates to the deployment.template.json (see navigation pane on the left) to configure the edgeHub module to schedule on a node with a specific label.

{
  "$schema-template": "2.0.0",
  "modulesContent": {
    "$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": "azureiotedge/azureiotedge-hub:latest",
              "createOptions": {
                "HostConfig": {
                  "PortBindings": {
                    "5671/tcp": [{
                      "HostPort": "5671"
                    }],
                    "8883/tcp": [{
                      "HostPort": "8883"
                    }],
                    "443/tcp": [{
                      "HostPort": "443"
                    }]
                  }
                },
+               "k8s-experimental": {
+                 "nodeSelector": {
+                   "edgehub": "true"
+                 }
+               }
              }
            }
          }
        },
        "modules": {}
      }
    },
    "$edgeHub": {
      "properties.desired": {
        "schemaVersion": "1.0",
        "routes": {
          "upstream": "FROM /messages/* INTO $upstream"
        },
        "storeAndForwardConfiguration": {
          "timeToLiveSecs": 7200
        }
      }
    }
  }
}

🗒

We've used edgeHub as an example here, however you can specify K8s extended createOptions for any module in the edge deployment.

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.
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.
In a few seconds, you'll see a new edgeHub container instantiated on the node you added the edgehub=true label to. You can confirm this by checking the NODE column the edgehub pod in the output from below:
```
kubectl get pods -n nodeselector -o wide
```

Cleanup

# Cleanup
helm del node-selector-example -n nodeselector && \
kubectl delete ns nodeselector

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