Token exchange service - Amazon IoT Greengrass
VersionsTypeOperating systemDependenciesConfigurationLocal log fileChangelog
Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

Token exchange service

The token exchange service component (aws.greengrass.TokenExchangeService) provides Amazon credentials that you can use to interact with Amazon services in your custom components.

The token exchange service runs an Amazon Elastic Container Service (Amazon ECS) container instance as a local server. This local server connects to the Amazon IoT credentials provider using the Amazon IoT role alias that you configure in the Greengrass core nucleus component. The component provides two environment variables, AWS_CONTAINER_CREDENTIALS_FULL_URI and AWS_CONTAINER_AUTHORIZATION_TOKEN. AWS_CONTAINER_CREDENTIALS_FULL_URI defines the URI to this local server. When a component creates an Amazon SDK client, the client recognizes this URI environment variable and uses the token in the AWS_CONTAINER_AUTHORIZATION_TOKEN to connect to the token exchange service and retrieve Amazon credentials. This allows Greengrass core devices to call Amazon service operations. For more information about how to use this component in custom components, see Interact with Amazon services.

Important

Support to acquire Amazon credentials in this way was added to the Amazon SDKs on July 13th, 2016. Your component must use an Amazon SDK version that was created on or after that date. For more information, see Using a supported Amazon SDK in the Amazon Elastic Container Service Developer Guide.

Versions

This component has the following versions:

  • 2.0.x

Type

This component is a generic component (aws.greengrass.generic). The Greengrass nucleus runs the component's lifecycle scripts.

For more information, see Component types.

Operating system

This component can be installed on core devices that run the following operating systems:

  • Linux

  • Windows

Dependencies

This component doesn't have any dependencies.

Configuration

This component provides the following configuration parameters that you can customize when you deploy the component.

port

The port to use for token exchange service connections. The token exchange service will restart after port configuration changes.

Example: Configuration merge update
{
   "port": 2020
}

Local log file

This component uses the same log file as the Greengrass nucleus component.

Linux
/greengrass/v2/logs/greengrass.log
Windows
C:\greengrass\v2\logs\greengrass.log
To view this component's logs

  • Run the following command on the core device to view this component's log file in real time. Replace /greengrass/v2 or C:\greengrass\v2 with the path to the Amazon IoT Greengrass root folder.

    Linux
    sudo tail -f /greengrass/v2/logs/greengrass.log
    Windows (PowerShell)
    Get-Content C:\greengrass\v2\logs\greengrass.log -Tail 10 -Wait

Changelog

The following table describes the changes in each version of the component.

Version

Changes

2.0.3

Initial version.