Communicate with the Greengrass nucleus, other components, and AWS IoT Core

This page was generated from content adapted from the AWS Developer Guide

Publish/subscribe local messages

• Note You can't use this publish/subscribe IPC service to publish or subscribe to AWS IoT Core MQTT. For more information about how to exchange messages with AWS IoT Core MQTT, see Publish/subscribe AWS IoT Core MQTT messages.

Publish/subscribe AWS IoT Core MQTT messages

• Note This MQTT messaging IPC service lets you exchange messages with AWS IoT Core. For more information about how to exchange messages between components, see Publish/subscribe local messages.

Interact with component lifecycle

• Important Local deployments don't notify components before updates.

• Tip You can follow a tutorial to learn how to develop a component that conditionally defers component updates. For more information, see Tutorial: Develop a Greengrass component that defers component updates.

• Tip You can follow a tutorial to learn how to develop a component that conditionally defers component updates. For more information, see Tutorial: Develop a Greengrass component that defers component updates.

• Note This operation can't pause containerized processes, such as Docker containers. To pause and resume a Docker container, you can use the docker pause and docker resume commands.

• Important To use this operation, you must define an authorization policy that grants permission to use this operation. For more information, see Authorization.

• Important To use this operation, you must define an authorization policy that grants permission to do so. For more information, see Authorization.

Interact with component configuration

• Important Local deployments don't notify components of updates.

Retrieve secret values

• Important This example component prints the value of a secret, so use it only with secrets that store test data. Don't use this component to print the value of a secret that stores important information.

• NoteWe recommend that in a production environment, you reduce the scope of the authorization policy, so that the component retrieves only the secrets that it uses. You can change the * wildcard to a list of secret ARNs when you deploy the component.

Interact with local shadows

• NoteTo enable a core device to interact with client device shadows, you must also configure and deploy the MQTT bridge component. For more information, see Enable shadow manager to communicate with client devices.

Manage local deployments and components

• Note This feature is available for v2.6.0 and later of the Greengrass nucleus component.

• Note While you can restart any component, we recommend that you restart only generic components.

• Note While you can stop any component, we recommend that you stop only generic components.

Authenticate and authorize client devices

• Note This feature is available for v2.6.0 and later of the Greengrass nucleus component.