Verify the Lambda function is running on the core device - AWS IoT Greengrass

You are viewing the documentation for AWS IoT Greengrass Version 1. AWS IoT Greengrass Version 2 is the latest major version of AWS IoT Greengrass. For more information about using AWS IoT Greengrass V2, see the AWS IoT Greengrass Version 2 Developer Guide.

Verify the Lambda function is running on the core device

  1. From the navigation pane of the AWS IoT console, choose Test.

    
                            Screenshot of AWS IoT console with Test highlighted.
  2. Choose Subscribe to topic, and configure the following fields:

    • For Subscription topic, enter hello/world. (Don't choose Subscribe yet.)

    • For Quality of Service, choose 0.

    • For MQTT payload display, choose Display payloads as strings.

     

    
                            Screenshot of MQTT test client page with topic subscription
                                information.
  3. Under Subscriptions, choose the hello/world topic.

Assuming the Lambda function is running on your device, it publishes messages similar to the following to the hello/world topic:


                    Screenshot of message sent to the hello/world topic with message
                        highlighted.

Although the Lambda function continues to send MQTT messages to the hello/world topic, don't stop the AWS IoT Greengrass daemon. The remaining modules are written with the assumption that it's running.

You can delete the function and subscription from the group:

  • From the Lambdas page, choose the ellipsis (), and then choose Remove function.

  • From the Subscriptions page, choose the ellipsis (), and then choose Delete.

The function and subscription are removed from the core during the next group deployment.