https://github.com/olafwrieden/telemetry-data-generator
A repository for simulating device telemetry with an Azure Function and feeding it into an Azure Event Hub.
https://github.com/olafwrieden/telemetry-data-generator
azure data-generator iot ot telemetry
Last synced: about 1 month ago
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A repository for simulating device telemetry with an Azure Function and feeding it into an Azure Event Hub.
- Host: GitHub
- URL: https://github.com/olafwrieden/telemetry-data-generator
- Owner: olafwrieden
- Created: 2023-10-17T06:32:41.000Z (over 2 years ago)
- Default Branch: main
- Last Pushed: 2024-01-22T01:22:25.000Z (over 2 years ago)
- Last Synced: 2025-05-23T00:39:56.479Z (about 1 year ago)
- Topics: azure, data-generator, iot, ot, telemetry
- Language: TypeScript
- Homepage: https://medium.com/@olafwrieden/build-your-own-telemetry-data-generator-to-simulate-iot-and-ot-devices-43eaa954f1f8
- Size: 91.8 KB
- Stars: 3
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# Telemetry Data Generator
This is a simple telemetry generator that can be used to generate telemetry data for testing purposes. It was built for the Azure Data Explorer Microhack as a replacement for the IoT Central dependency.
## Read the Blog
This repository accompanies my blog post on Medium titled _[Build your own Telemetry Data Generator to Simulate IoT and OT Devices](https://medium.com/@olafwrieden/build-your-own-telemetry-data-generator-to-simulate-iot-and-ot-devices-43eaa954f1f8)_ which it walks you through customising this generator to suit the unique shape of your data - this way you can mimic your real-world data in a test environment.
[](https://medium.com/@olafwrieden/build-your-own-telemetry-data-generator-to-simulate-iot-and-ot-devices-43eaa954f1f8)
## Deploy to Azure
To deploy this generator to Azure, click the button below. You will need an Azure Subscription and permission to create the resources shown in the image.
[](https://portal.azure.com/#create/Microsoft.Template/uri/https%3A%2F%2Fraw.githubusercontent.com%2Folafwrieden%2Ftelemetry-data-generator%2Fmain%2Finfra%2Fmain.json)
## How it works
The generator simulates telemetry from 30 devices whose ids are defined in the [`src/deviceIds.ts`](/src/deviceIds.ts) file. We want the generator to emit payloads for the same simulated devices each time, thus we hardcode the device ids to keep them consistent between runs.
Every 1 minute, the [`src/functions/TelemetryGenerator.ts`](src/functions/TelemetryGenerator.ts) runs and emits a payload for each device ID. The payload is a JSON object which matches the expected format for the IoT Central API.
The payload array is then written onto the Event Hub for later ingestion into a KQL Database (or other downstream system).
## How to use
To adjust the Event Hub name and connection string, edit the [`src/functions/TelemetryGenerator.ts`](src/functions/TelemetryGenerator.ts) file. Here you can also adjust the frequency of the payload generation.
```typescript
...
// Schedule the function to run every minute and push into the iotdata Event Hub.
app.timer("TelemetryGenerator", {
schedule: "0 */1 * * * *",
handler: TelemetryGenerator,
return: output.eventHub({
eventHubName: "iotdata", // <-- Name of the Azure Event Hub
connection: "EventHubConnection", // <-- Environment variable (connection string)
}),
});
```
Be sure to supply the `EventHubConnection` environment variable when deploying the function app. The value is the connection string of your Azure Event Hubs Namespace.
### In Development
Locally this can be supplied in a `local.settings.json` file like so:
```json
{
"IsEncrypted": false,
"Values": {
"AzureWebJobsStorage": "DefaultEndpointsProtocol=...",
"FUNCTIONS_WORKER_RUNTIME": "node",
"AzureWebJobsFeatureFlags": "EnableWorkerIndexing",
"EventHubConnection": "Endpoint=sb://..."
}
}
```
### In Production
Add the `EventHubConnection` environment variable in the Azure Function's Configuration settings. The value should be the Azure Event Hub connection string, e.g.
| Key | Value |
| -------------------- | ------------------- |
| `EventHubConnection` | `Endpoint=sb://...` |