Azure IoT Edge- Who is cooler? dotnet, node or python?

Series

Part 1 - dotnet vs python vs node - temperature emission - who is cooler?
Part 2 - Developing modules
Part 3 - Custom Containers using Apache Nifi
Part 4 - Custom Module using TimescaleDB
Part 5 - Custom Module using Grafana

Intro

This code will run through creating an end to end demo of building & deploying an Azure IoT Edge solution solution.

Code for this example lives here

https://github.com/chrismckelt/edgy

What are we building?

This solution demonstrates an air-conditioning monitoring system where 3 room sensors are publishing their temperature over time. When a room gets too hot the air conditioner for that room is turned on. Once the room is cooled it is turned off.

Three ‘data generator’ modules publish a message with the following properties.

Timestamp
Temperature – room temp in Celsius
IsAirConditionerOn – true/false
TagKey – room name (in this case dotnet, node, python)

Three ‘data recorder’ modules subscribe to the published temperature messages and save the data in a time series database.

A custom module will listen to all temperature messages and analyse when a room is too hot. Sending a message to turn the rooms air conditioner on.

Demo Focus Areas

show local debug/development options & remote/real deployment
how to create and configure an Azure IOT Hub environment in Azure using Azure CLI scripts
coding custom modules in .Net, Python, NodeJS (sorry Java)
using existing Azure IoT Edge marketplace modules
using non-edge marketplace modules (docker images) to save data with Timescale
connecting a data flow engine ( Apache Nifi) to the Edge MQTT Broker
viewing the data through a Grafana dashboard.

Getting started

In order to develop solutions for the edge:

Read Developing custom modules
Setup your machine using the Azure IoT EdgeHub Dev Tool
I recommend installing these VS code extensions
I recommend using Portainer for docker management both locally & on the deployed edge solution

Portainer running on http://localhost:9000/

Solution Overview

Azure Setup

You will need an Azure IoT Hub setup in Azure. For this demo I am using the free tier

The IoT Hub Free Edition is intended to encourage proof of concept projects. It enables you to transmit up to a total of 8,000 messages per day, and register up to 500 device identities. The device identity limit is only present for the Free Edition.

To build the environment I have used the Azure CLI and created scripts found here. Run the top 3 on your selected subscription to create the artefacts in Azure below:

Running

Modules

The code contains the docker build files , code & scripts to create the following modules

Code

Descriptions of folders and files

Folder / File	Description
config	automatically generate files from the deployment.templates.json (debug or prod) that are used to deploy the solution
modules	custom code, docker images for your IOT Edge solution
scripts	code to create the environment, build the code/docker images and deploy the solution
tools	certificate generator and other tools for solution support
.env	holds environment variables that populate the generated config files from the templates
deployment.debug.template.json	creates a file in the /config folder called ‘deployment.debug.json’ that populates environment variables, used for local development
deployment.prod.template.json	creates a file in the /config folder called ‘deployment.prod.json’ that populates environment variables, used for production like deployment