eventmaker

Utility to mock events with configurable format, random metric range, and frequency. The supported event publishers are

• stdout - prints events to the console
• http - posts events to specified URL (how-to)
• iothub - sends events to Azure IoT Hub (how-to)
• eventhub - sends events to Azure Event Hub (how-to)
• iotcore - sends events to GCP IoT Core
• pubsub - sends events to GCP Pub/Sub (how-to)
• sns - sends events to AWS SNS
• sqs - sends events to AWS SQS

usage

To run eventmaker and publish events to the console run

./eventmaker stdout --file conf/thermostat.yaml

The file parameter can be local file path or a remote URL (e.g. thermostat.yaml). For more information about all the flags and commands supported by the eventmaker use the --help or -h flag

./eventmaker -h

For instructions how to publish events to other targets see the how-to links above

events

The mocked event look like this

{
    "id": "fdf612b9-34a5-445e-9941-59c404ea9bef",
    "src_id": "device-1",
    "time": 1589745397,
    "label": "temp",
    "data": 70.79129651786347,
    "unit": "celsius"
}

• id - is a globally unique ID generated for each event
• src_id - is the device ID or name (configured using the --device flag at launch)
• time - is the epoch (aka Unix time) of when the event was generated

The label, data, and unit elements are based on the metrics defined in the template (see metrics section below)

metrics

eventmaker dynamically configures metrics based on template where you can

To create events, define one or more metrics in a template file where you configure the frequency in which that metric should be generated along with its type and range of value. For example, configuration for a virtual thermostat with temperature and humidity metrics would look like this

--- 
metrics: 
- label: temperature
  frequency: "1s"
  unit: celsius
  template: 
    type: float
    min: 86.1
    max: 107.5
- label: humidity
  frequency: "1s"
  unit: percent
  template: 
    type: int
    min: 0
    max: 100

That file where you define these metrics cab be either local (e.g. --file conf/example.yaml) or loaded from a remote URL (e.g. --file https://raw.githubusercontent.com/mchmarny/eventmaker/master/conf/thermostat.yaml)

example

To use eventmaker as a library, start by importing the package

go get -u github.com/mchmarny/eventmaker

Then create some metric templates

metrics := []event.MetricTemplate{
  {
    Label:     "temperature",
    Unit:      "celsius",
    Frequency: time.Duration(1 * time.Second),
    Template: event.ValueTemplate{
      Type: "float",
      Min:  39.1,
      Max:  73.5,
    },
  },
  {
    Label:     "humidity",
    Unit:      "percent",
    Frequency: time.Duration(1 * time.Minute),
    Template: event.ValueTemplate{
      Type: "int",
      Min:  0,
      Max:  100,
    },
  },
}

Create a publisher target using one of the event senders (stdout, iothub, http)

target, err := stdout.NewEventSender(ctx)
if err != nil {
  panic(err)
}

And finally create an instance of mocker with the previously created metrics and target and start it

mocker, err := mock.New("demo-device-1", metrics, target)
if err != nil {
  panic(err)
}

mocker.Start(ctx)

A complete working example is available here

Disclaimer

This is my personal project and it does not represent my employer. I take no responsibility for issues caused by this code. I do my best to ensure that everything works, but if something goes wrong, my apologies is all you will get.

License

This software is released under the Apache v2 License