iot-edge-module

Introduction

This repository contains the code of an example Azure IoT Edge module - it demonstrates the boilerplate code for the module itself as well as the service.

Preconditions

To install the IoT Edge CLI extension run the following command:

az extension add --name azure-cli-iot-ext

You must already have an Azure IoT Hub and Azure IoT Edge Device resources created.

Running the code

To build and push the Docker container image of the Azure IoT Edge module the following environment variables must be set:

• IOTEDGE_MODULE_IMAGE_URI

To build and push the Docker container image of the Azure IoT Edge module run the following commands:

docker build -t $IOTEDGE_MODULE_IMAGE_URI .
docker push $IOTEDGE_MODULE_IMAGE_URI

To create a Azure IoT Edge module deployment the following environment variables must be set:

• IOTHUB_NAME
• IOTEDGE_DEPLOYMENT_ID
• IOTEDGE_DEVICE_ID
• IOTEDGE_MODULE_NAME
• IOTEDGE_MODULE_IMAGE_URI

To create a Azure IoT Edge module deployment run the following commands:

envsubst '$IOTEDGE_MODULE_NAME$IOTEDGE_MODULE_IMAGE_URI' < iot-edge-deployment.json.template > iot-edge-deployment.json
az iot edge deployment create --hub-name $IOTHUB_NAME --deployment-id $IOTEDGE_DEPLOYMENT_ID --content iot-edge-deployment.json --target-condition "deviceId='$IOTEDGE_DEVICE_ID'"

To adjust the value in the module twin the following environment variables must be set:

• IOTHUB_SERVICE_CONNECTION_STRING
• IOTEDGE_DEVICE_ID
• IOTEDGE_MODULE_NAME
• IOTEDGE_MODULE_IMAGE_URI

To adjust the value in the module twin run the following command:

docker run --rm -it -e IOTHUB_SERVICE_CONNECTION_STRING=$IOTHUB_SERVICE_CONNECTION_STRING -e IOTEDGE_DEVICE_ID=$IOTEDGE_DEVICE_ID -e IOTEDGE_MODULE_NAME=$IOTEDGE_MODULE_NAME $IOTEDGE_MODULE_IMAGE_URI "$RANDOM"

This will result in the following (Docker) log entry of the module:

info: module.Program[0]
      Desired property change: {"value":8498,"$version":2}
info: module.Program[0]
      Sending current value as reported property

To find the connection string (for the IOTHUB_SERVICE_CONNECTION_STRING variable) follow this path on the Azure portal:

Iot Hub -> [Your IoT Hub Instance] -> Shared access policies -> service -> Connection string—primary key

Other materials

Cross-compiled Docker containers: https://docs.resin.io/reference/base-images/resin-base-images/#resin-xbuild-qemu