Differentiating Messages from aws.greengrass.telemetry.NucleusEmitter in a multi-core deployment

Question

We have multiple greengrass core devices that each have their own deploment. In each deployment, the 'aws.greengrass.telemetry.NucleusEmitter' is configured as follows:
{
  "reset": [],
  "merge": {
    "pubSubPublish": "false",
    "mqttTopic": "",
    "telemetryPublishIntervalMs": 
  }
}
.

This allows us to distinguish between the different MQTT messages returned by the edge devices as they each arrive on a different topic. 
If we were to place all gg cores under the same deployment, is there a way of distinguishing between the messages that will be published on that topic ? 
Our requirement is to identify individual gg core devices that have memory/component issues, using the  'aws.greengrass.telemetry.NucleusEmitter' component, while having all devices under one deployment.

Accepted Answer

Nucleus 2.6 will support interpolation in component configuration (currently it is only supported in the component recipe Lifecycle section). That will enable you to use the `{iot:thingName}` variable in the `mqttTopic` config. Unfortunately, this hasn't been released yet and I can't share a release date. But once that happens, this will definitely be the easiest way.

https://docs.aws.amazon.com/greengrass/v2/developerguide/component-recipe-reference.html#recipe-variables

In the interim, you can either create individual Thing deployments containing only the `aws.greengrass.telemetry.NucleusEmitter` component. Or, you can write your own custom bridge component that forwards messages from `$local/greengrass/telemetry` to an MQTT topic of your choice. This component can read Nucleus ThingName information from environment variables.

Answer

This does not appear to be working yet as far as I can tell.  I have a deployment that includes the NucleusEmitter component, as well as Nucleus 2.6.0.  I have the configuration for `mqttTopic` set to `device/{iot:ThingName}/telemetry`.  However using the MQTT test client subscribed to `device/+/#`, I can see that the thing name is not being interpolated.

Differentiating Messages from aws.greengrass.telemetry.NucleusEmitter in a multi-core deployment

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